on master help sign in
.github/workflows/build.yamlnew file+26
since splitsnapshots
unifiedsplit
@@ -0,0 +1,26 @@
1+name: Build
2+on: [push, pull_request, release]
3+jobs:
4+ build:
5+ runs-on: ubuntu-latest
6+ steps:
7+ - uses: actions/checkout@v2.3.4
8+ with:
9+ persist-credentials: false
10+ submodules: true
11+
12+ - uses: cachix/install-nix-action@v14.1
13+ with:
14+ nix_path: nixpkgs=channel:nixos-unstable
15+ extra_nix_config: |
16+ trusted-public-keys = cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY= hydra.iohk.io:f/Ea+s+dFdN+3Y/G+FDgSq+a5NEWhJGzdjvKNGv0/EQ=
17+ substituters = https://cache.nixos.org/ https://cache.iog.io
18+
19+ - uses: cachix/cachix-action@v10
20+ with:
21+ name: rel8
22+ authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
23+
24+ - run: nix-build -A hsPkgs.rel8.components.library
25+ - run: nix-build -A hsPkgs.rel8.checks.tests
26+ - run: nix-build shell.nix
Changelog.mdnew file+159
@@ -0,0 +1,159 @@
1+# 1.4.0.0 (2002-08-17)
2+
3+## Breaking changes
4+
5+* The behavior of `greatest`/`least` has been corrected, and was previously flipped. ([#183](https://github.com/circuithub/rel8/pull/183))
6+
7+## New features
8+
9+* `NullTable`/`HNull` have been added. This is an alternative to `MaybeTable` that doesn't use a tag columns. It's less flexible (no `Functor` or `Applicative` instance) and is meaningless when used with a table that has no non-nullable columns (so nesting `NullTable` is redundant). But in situations where the underlying `Table` does have non-nullable columns, it can losslessly converted to and from `MaybeTable`. It is useful for embedding into a base table when you don't want to store the extra tag column in your schema. ([#173](https://github.com/circuithub/rel8/pull/173))
10+* Add `fromMaybeTable`. ([#179](https://github.com/circuithub/rel8/pull/179))
11+* Add `alignMaybeTable`. ([#196](https://github.com/circuithub/rel8/pull/196))
12+
13+## Improvements
14+
15+* Optimize implementation of `AltTable` for `Tabulation` ([#178](https://github.com/circuithub/rel8/pull/178))
16+
17+## Other
18+
19+* Documentation improvements for `HADT`. ([#177](https://github.com/circuithub/rel8/pull/177))
20+* Document example usage of `groupBy`. ([#184](https://github.com/circuithub/rel8/pull/184))
21+* Build with and require Opaleye >= 0.9.3.3. ([#190](https://github.com/circuithub/rel8/pull/190))
22+* Build with `hasql` 1.6. ([#195](https://github.com/circuithub/rel8/pull/195))
23+
24+# 1.3.1.0 (2022-01-20)
25+
26+## Other
27+
28+* Rel8 now requires Opaleye >= 0.9.1. ([#165](https://github.com/circuithub/rel8/pull/165))
29+
30+# 1.3.0.0 (2022-01-31)
31+
32+## Breaking changes
33+
34+* `div` and `mod` have been changed to match Haskell semantics. If you need the PostgreSQL `div()` and `mod()` functions, use `quot` and `rem`. While this is not an API change, we feel this is a breaking change in semantics and have bumped the major version number. ([#155](https://github.com/circuithub/rel8/pull/155))
35+
36+## New features
37+
38+* `divMod` and `quotRem` functions have been added, matching Haskell's `Prelude` functions. ([#155](https://github.com/circuithub/rel8/pull/155))
39+* `avg` and `mode` aggregation functions to find the mean value of an expression, or the most common row in a query, respectively. ([#152](https://github.com/circuithub/rel8/pull/152))
40+* The full `EqTable` and `OrdTable` classes have been exported, allowing for instances to be manually created. ([#157](https://github.com/circuithub/rel8/pull/157))
41+* Added `like` and `ilike` (for the `LIKE` and `ILIKE` operators). ([#146](https://github.com/circuithub/rel8/pull/146))
42+
43+## Other
44+
45+* Rel8 now requires Opaleye 0.9. ([#158](https://github.com/circuithub/rel8/pull/158))
46+* Rel8's test suite supports Hedgehog 1.1. ([#160](https://github.com/circuithub/rel8/pull/160))
47+* The documentation for binary operations has been corrected. ([#162](https://github.com/circuithub/rel8/pull/162))
48+
49+# 1.2.2.0 (2021-11-21)
50+
51+## Other
52+
53+* Support GHC 9.2 ([#145](https://github.com/circuithub/rel8/pull/145))
54+* Correct the documentation for `except` ([#147](https://github.com/circuithub/rel8/pull/147))
55+* Support `hasql` 1.5 ([#149](https://github.com/circuithub/rel8/pull/149))
56+
57+# 1.2.1.0 (2021-11-21)
58+
59+## New features
60+
61+* `castTable` has been added, which casts all columns selected from in `Query` according to the types of columns. This can occasionally be useful when using `many`/`some` on older PostgreSQL versions. ([#137](https://github.com/circuithub/rel8/pull/137))
62+
63+* Added `<:`, `<=:`, `>:`, `>=:`, `greatest` and `least`, which sort all columns in a table lexicographically. These operators are like the `<.` operators which operate on `Expr`s, but the `<:` operate on entire tables. ([#139](https://github.com/circuithub/rel8/pull/139))
64+
65+## Other
66+
67+* Support opaleye-0.8 ([#142](https://github.com/circuithub/rel8/pull/142))
68+
69+# 1.2.0.0 (2021-10-22)
70+
71+## New features
72+
73+* New `$*` and `$+` operators for projecting out of `ListTable` and `NonEmptyTable` respectively (analogous to the existing `$?` for `MaybeTable`). ([#125](https://github.com/circuithub/rel8/pull/125))
74+
75+## Bug fixes
76+
77+* Fix `UPSERT` support (and add tests), which was broken due to a typo inside Rel8 that made it impossible to construct `Projection`s which are needed by `UPSERT`. ([#134](https://github.com/circuithub/rel8/pull/134))
78+
79+* Remove `DBMin` and `DBMax` instances for `Bool`, which are invalid as far as Postgres is concerned. `and` and `or` can be used to achieve the same thing. ([#126](https://github.com/circuithub/rel8/pull/126))
80+
81+* Fix `aggregateMaybeTable`, `aggregateEitherTable` and `aggregateTheseTable`, which generated invalid SQL previously. ([#127](https://github.com/circuithub/rel8/pull/127))
82+
83+## Breaking changes
84+
85+* `rebind` now takes an additional argument for the "name" of the binding. ([#128](https://github.com/circuithub/rel8/pull/128))
86+
87+# 1.1.0.0 (2021-07-16)
88+
89+## New features
90+
91+* You can derive `Rel8able` for "vanilla" higher-kinded data types - data types that don't use the `Column` type family. For example, the following is now possible:
92+
93+ ```haskell
94+ data MyTable f = MyTable
95+ { myTableX :: f Int32
96+ , myTableY :: f Text
97+ } deriving (Generic, Rel8able)
98+ ```
99+
100+* The `Projectable` and `Biprojectable` type classes have been introduced. These classes model a type of functors and bifunctors (respectively) on tables, where the mapping function is only able to rearrange columns. For example, the following is now possible:
101+
102+ ```haskell
103+ x <- project myTableX <$> many ...
104+ ```
105+
106+* `Insert`'s `onConflict` field now has a new option - `DoUpdate`. This maps to PostgreSQL's `ON CONFLICT DO UPDATE` syntax, which provides upsert support. ([#85](https://github.com/circuithub/rel8/pull/85))
107+
108+* `Insert`, `Update` and `Delete` has all been expanded to work with `Query`s. In particular:
109+
110+ * `Delete` now supports a `USING` sub-query
111+ * `Update` now supports a `FROM` sub-query
112+ * `Insert` can delete the result of any arbitrary `Query` (providing the types match)
113+
114+* The new `Rel8.Tabulate` module has been added, which gives a `Map`-esque interface to writing and composing queries. ([#70](https://github.com/circuithub/rel8/pull/70))
115+
116+* The new `indexed` `Query -> Query` function was added. This function augments each row in a query with it's 0-based index. ([#117](https://github.com/circuithub/rel8/pull/117))
117+
118+## Breaking changes
119+
120+* `Insert`, `Delete` and `Update` have all changed. In particular, for `Insert` users should now replace `rows = xs` with `rows = values xs`. ([#85](https://github.com/circuithub/rel8/pull/85))
121+
122+* Rename `whereExists` and `whereNotExists` to `present` and `absent` respectively. ([#57](https://github.com/circuithub/rel8/pull/57))
123+
124+* Simplify `evaluate` to run directly inside the `Query` monad, rendering the `Evaluate` monad unnecessary. ([#56](https://github.com/circuithub/rel8/pull/56))
125+
126+* The `Labelable` type class has been removed as it's no longer necessary. This class was mostly internal, though was visible in some public API functions. ([#76](https://github.com/circuithub/rel8/pull/76))
127+
128+* `EitherTable`, `ListTable`, `MaybeTable`, `NonEmptyTable` and `TheseTable` now all have an extra parameter which tracks the context of the table. If you manually specified any types before, you need to provide this parameter - usually `Expr` will be the correct choice. ([#101](https://github.com/circuithub/rel8/pull/101))
129+
130+* We've done a lot of work to simplify the internals of Rel8, but some of these are breaking changes. However, most of these API changes shouldn't affect users as they are mostly types used in type inference, or affect classes where users don't need to define their own instances.
131+
132+ * The kind of a `Rel8able` is now `(Type -> Type) -> Type`. Previously it was `(X -> Type) -> Type`.
133+ * `Table` has a new associated type - `FromExprs`. This was previously an open type family.
134+ * `Table` has a new associated type - `Transpose` - and `Recontextualise` has been renamed to `Transposes`. This `Transposes` class now operates in terms of `Transpose`.
135+
136+* `select`, `insert`, `update` and `delete` now produce Hasql `Statement`s, rather than actually running the statement as IO. This allows Rel8 to be used with transaction/connection-managing monads like [`hasql-transaction`](https://hackage.haskell.org/package/hasql-transaction). ([#94](https://github.com/circuithub/rel8/pull/94))
137+
138+## Bug fixes
139+
140+* Fixes a bug where cartesian products of queries using `catListTable`, `catNonEmptyTable`, `catList` and `catNonEmpty` would incorrectly be zipped instead. ([#61](https://github.com/circuithub/rel8/pull/61))
141+
142+* Require Opaleye 0.7.3.0. This version has better support for lateral queries, which can improve query plans, especially in `optional`/`LEFT JOIN` ([#72](https://github.com/circuithub/rel8/pull/72))
143+
144+* Rel8 now compiles with GHC 9. ([#97](https://github.com/circuithub/rel8/pull/97))
145+
146+## Other changes
147+
148+* `exists` is now implemented in terms of the SQL `EXISTS` keyword. ([#69](https://github.com/circuithub/rel8/pull/69))
149+
150+* `alignBy` no longer requires `Table`s. ([#67](https://github.com/circuithub/rel8/pull/67))
151+
152+
153+# 1.0.0.1 (2021-06-21)
154+
155+This release contains various fixes for documentation.
156+
157+# 1.0.0.0 (2021-06-18)
158+
159+* Initial release.
Doctest.hsdeleted−53
@@ -1,53 +0,0 @@
1−{-# language BlockArguments #-}
2−{-# language OverloadedStrings #-}
3−
4−module Main where
5−
6−-- base
7−import Control.Exception ( bracket, throwIO )
8−import Data.Foldable ( traverse_ )
9−import System.Environment ( lookupEnv, setEnv )
10−
11−-- base-compat
12−import System.Environment.Compat ( unsetEnv )
13−
14−-- bytestring
15−import Data.ByteString.Char8 ( unpack )
16−
17−-- doctest
18−import Test.DocTest ( doctest )
19−
20−-- hasql
21−import Hasql.Connection ( acquire, release )
22−import Hasql.Session ( run, sql )
23−
24−-- rel8
25−import Build_doctests ( flags, module_sources, pkgs )
26−
27−-- tmp-postgres
28−import Database.Postgres.Temp ( toConnectionString, verboseConfig, with, withConfig )
29−
30−
31−main :: IO ()
32−main = do
33− nixGhcLibdir <- lookupEnv "NIX_GHC_LIBDIR"
34− unsetEnv "GHC_ENVIRONMENT"
35− either throwIO return =<< with \db -> do
36− setEnv "TEST_DATABASE_URL" (unpack (toConnectionString db))
37− bracket (either (error . show) return =<< acquire (toConnectionString db)) release \conn -> do
38− flip run conn do
39− sql "create table author ( author_id serial primary key, name text not null, url text )"
40− sql "create table project ( author_id int not null references author (author_id), name text not null )"
41−
42− sql "insert into author ( name, url ) values ( 'Ollie', 'https://ocharles.org.uk' )"
43− sql "insert into author ( name, url ) values ( 'Bryan O''Sullivan', null )"
44− sql "insert into author ( name, url ) values ( 'Emily Pillmore', 'https://cohomolo.gy' )"
45− sql "insert into project ( author_id, name ) values ( 1, 'rel8' )"
46− sql "insert into project ( author_id, name ) values ( 2, 'aeson' )"
47− sql "insert into project ( author_id, name ) values ( 2, 'text' )"
48−
49− doctest (args nixGhcLibdir)
50−
51− where
52− args nixGhcLibdir =
53− flags ++ pkgs ++ foldMap (\x -> ["-package-db" <> x <> "/package.conf.d"]) nixGhcLibdir ++ module_sources
LICENSE+1−1
@@ -1,4 +1,4 @@
1−Copyright 2020 Oliver Charles
1+Copyright 2021 Oliver Charles
2
2
3All rights reserved.
3All rights reserved.
4
4
README.mdnew file+17
@@ -0,0 +1,17 @@
1+# Welcome!
2+
3+Welcome to Rel8! Rel8 is a Haskell library for interacting with PostgreSQL databases, built on top of the fantastic Opaleye library.
4+
5+The main objectives of Rel8 are:
6+
7+* *Conciseness*: Users using Rel8 should not need to write boiler-plate code. By using expressive types, we can provide sufficient information for the compiler to infer code whenever possible.
8+
9+* *Inferrable*: Despite using a lot of type level magic, Rel8 aims to have excellent and predictable type inference.
10+
11+* *Familiar*: writing Rel8 queries should feel like normal Haskell programming.
12+
13+Rel8 was presented at ZuriHac 2021. If you want to have a brief overview of what Rel8 is, and a tour of the API - check out the video below:
14+
15+[![Rel8 presentation at ZuriHac 2021](https://img.youtube.com/vi/3uwrtjxiq6E/hqdefault.jpg)](http://www.youtube.com/watch?v=3uwrtjxiq6E)
16+
17+For more details, check out the [official documentation](https://rel8.readthedocs.io/en/latest/).
Setup.hsdeleted−6
@@ -1,6 +0,0 @@
1−module Main where
2−
3−import Distribution.Extra.Doctest (defaultMainWithDoctests)
4−
5−main :: IO ()
6−main = defaultMainWithDoctests "doctests"
cabal.project.haskell-nixnew file+4
@@ -0,0 +1,4 @@
1+-- Haskell.nix overrides. We don't put these in cabal.project, because Cabal
2+-- will interpret them as local packages, and try to build them when we cabal
3+-- build. The only reason we have to specify these is for Haskell.nix to know to
4+-- override these packages by fetching them rather than using Hackage.
default.nix+7−5
@@ -1,24 +1,26 @@
1−let
1+let
2 haskellNix = import (import ./nix/sources.nix)."haskell.nix" {};
2 haskellNix = import (import ./nix/sources.nix)."haskell.nix" {};
3
3
4− nixpkgsSrc = haskellNix.sources.nixpkgs-2009;
4+ nixpkgsSrc = haskellNix.sources.nixpkgs-unstable;
5
5
6 nixpkgsArgs = haskellNix.nixpkgsArgs;
6 nixpkgsArgs = haskellNix.nixpkgsArgs;
7
7
8− compiler-nix-name = "ghc8103";
8+ compiler-nix-name = "ghc924";
9
9
10 pkgs = import nixpkgsSrc nixpkgsArgs;
10 pkgs = import nixpkgsSrc nixpkgsArgs;
11
11
12−in
12+in
13pkgs.haskell-nix.project {
13pkgs.haskell-nix.project {
14 inherit compiler-nix-name;
14 inherit compiler-nix-name;
15
15
16+ cabalProjectLocal = builtins.readFile ./cabal.project.haskell-nix;
17+
16 src = pkgs.haskell-nix.haskellLib.cleanGit {
18 src = pkgs.haskell-nix.haskellLib.cleanGit {
17 name = "rel8";
19 name = "rel8";
18 src = ./.;
20 src = ./.;
19 };
21 };
20
22
21− modules = [
23+ modules = [
22 { packages.rel8 = {
24 { packages.rel8 = {
23 preCheck = ''
25 preCheck = ''
24 export PATH="${pkgs.postgresql}/bin:${"$PATH"}"
26 export PATH="${pkgs.postgresql}/bin:${"$PATH"}"
docs/Makefilenew file+19
@@ -0,0 +1,19 @@
1+# Minimal makefile for Sphinx documentation
2+#
3+
4+# You can set these variables from the command line.
5+SPHINXOPTS =
6+SPHINXBUILD = sphinx-build
7+SOURCEDIR = .
8+BUILDDIR = _build
9+
10+# Put it first so that "make" without argument is like "make help".
11+help:
12+ @$(SPHINXBUILD) -M help "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)
13+
14+.PHONY: help Makefile
15+
16+# Catch-all target: route all unknown targets to Sphinx using the new
17+# "make mode" option. $(O) is meant as a shortcut for $(SPHINXOPTS).
18+%: Makefile
19+ @$(SPHINXBUILD) -M $@ "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)
docs/concepts/dbtype.rstnew file+175
@@ -0,0 +1,175 @@
1+``DBType``
2+==========
3+
4+The ``DBType`` type class provides a bridge between database expression values
5+and Haskell values. Rel8 comes with stock instances for most types that come
6+predefined with PostgreSQL, such as `int4` (which is represented as by
7+``Data.Int.Int32``) and timestamptz (which is ``UTCTime`` from ``Data.Time``).
8+This means that you need at least one ``DBType`` instance per database type,
9+though most of these primitive ``DBType``\s should already be available.
10+
11+Combining ``newtype`` and ``DBType``
12+------------------------------------
13+
14+You can define new instances of ``DBType`` by using Haskell "generalized
15+newtype deriving" strategy. This is useful when you have a common database
16+type, but need to interpret this type differently in different contexts. A very
17+common example here is with auto-incrementing ``id`` counters. In PostgreSQL,
18+it's common for a table to have a primary key that uses the ``serial`` type,
19+which means the key is an ``int8`` with a default value for ``INSERT``. In
20+Rel8, we could use ``Int64`` (as ``Int64`` is the ``DBType`` instance for
21+``int8``), but we can be even clearer if we make a ``newtype`` for each *type*
22+of id.
23+
24+If our database has users and orders, these tables might both have ids, but
25+they are clearly not meant to be treated as a common type. Instead, we can make
26+these types clearly different by writing::
27+
28+ newtype UserId = UserId { getUserId :: Int64 }
29+ deriving newtype DBType
30+
31+ newtype OrderId = OrderId { getOrderId :: Int64 }
32+ deriving newtype DBType
33+
34+Now we can use ``UserId`` and ``OrderId`` in our Rel8 queries and definitions,
35+and Haskell will make sure we don't accidentally use an ``OrderId`` when we're
36+looking up a user.
37+
38+If you would like to use this approach but can't use generalized newtype
39+deriving, the same can be achived by using ``mapTypeInformation``::
40+
41+ instance DBType UserId where
42+ typeInformation = mapTypeInformation UserId getUserId typeInformation
43+
44+Parsing with ``DBType``
45+-----------------------
46+
47+``DBType``\s can also *refine* database types with parsing, which allows you to
48+map more structured Haskell types to a PostgreSQL database. This allows you to
49+use the capabalities of Haskell's rich type system to make it harder to write
50+incorrect queries. For example, we might have a database where we need to store
51+the status of an order. In Haskell, we might write:
52+
53+.. code-block:: haskell
54+
55+ data OrderStatus = PaymentPending | Paid | Packed | Shipped
56+
57+In our PostgreSQL we have a few choices, but for now we'll assume that they are
58+stored as ``text`` values.
59+
60+In order to use this type in Rel8 queries, we need to write an instance of
61+``DBType`` for ``OrderStatus``. One approach is to use
62+``parseTypeInformation``, which allows you to refine an existing ``DBType``::
63+
64+ instance DBType OrderStatus where
65+ typeInformation = parseTypeInformation parser printer typeInformation
66+ where
67+ parser :: Text -> Either String OrderStatus
68+ parser "PaymentPending" = Right PaymentPending
69+ parser "Paid" = Right Paid
70+ parser "Packed" = Right Packed
71+ parser "Shipped" = Right Shipped
72+ parser other = Left $ "Unknown OrderStatus: " <> unpack other
73+
74+ printer :: OrderStatus -> Text
75+ printer PaymentPending = "PaymentPending"
76+ printer Paid = "Paid"
77+ printer Packed = "Packed"
78+ printer Shipped = "Shipped"
79+
80+Deriving ``DBType`` via ``ReadShow``
81+------------------------------------
82+
83+The ``DBType`` definition for ``OrderStatus`` above is a perfectly reasonable
84+definition, though it is quite verbose and tedious. Rel8 makes it easy to map
85+Haskell types that are encoded using ``Read``/``Show`` via the ``ReadShow``
86+wrapper. An equivalent ``DBType`` definition using ``ReadShow`` is::
87+
88+ data OrderStatus = PaymentPending | Paid | Packed | Shipped
89+ deriving stock (Read, Show)
90+ deriving DBType via ReadShow OrderStatus
91+
92+Storing structured data with ``JSONEncoded``
93+--------------------------------------------
94+
95+It can occasionally be useful to treat PostgreSQL more like a document store,
96+storing structured documents as JSON objects. Rel8 comes with support for
97+serializing values into structured representations through the ``JSONEncoded``
98+and ``JSONBEncoded`` deriving-via helpers.
99+
100+There usage is very similar to ``ReadShow`` - simply derive ``DBType via
101+JSONEncoded``, and Rel8 will use ``ToJSON`` and ``FromJSON`` instances (from
102+``aeson``) to serialize the given type.
103+
104+For example, a project might use event sourcing with a table of events. Each
105+row in this table is an event, but this event is stored as a JSON object. We
106+can use this type with Rel8 by writing::
107+
108+ data Event = UserCreated UserCreatedData | OrderCreated OrderCreatedData
109+ deriving stock Generic
110+ deriving anyclass (ToJSON, FromJSON)
111+ deriving DBType via JSONBEncoded Event
112+
113+Here we used ``JSONBEncoded``, which will serialize to PostgreSQL ``jsonb``
114+(binary JSON) type, which is generally the best choice.
115+
116+The ``DBType`` subtypes
117+-----------------------
118+
119+``DBEq``
120+^^^^^^^^
121+
122+The ``DBEq`` type class represents the subclass of database types that support
123+equality. By supporting equality, we mean that a type supports the ``=``
124+operator, and also has a suitable notion of equality for operations like
125+``GROUP BY`` and ``DISTINCT``. On the one hand, this class is like Haskell's
126+``Eq`` type class. The main difference is that this class has no methods.
127+
128+``DBOrd``
129+^^^^^^^^^
130+
131+The ``DBOrd`` type class represents the subclass of database types that support
132+the normal comparison operators - ``<``, ``<=``, ``>=`` and ``>``.
133+
134+``DBMax`` and ``DBMin``
135+^^^^^^^^^^^^^^^^^^^^^^^
136+
137+The type classes indicate that a database type supports the ``min()`` and
138+``max()`` aggregation functions.
139+
140+``DBSemigroup`` and ``DBMonoid``
141+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
142+
143+These type classes exist to give Rel8's API a similar feel to Haskell
144+programming. Many database types have a sensible monoid structure, with the
145+presence of a ``mempty``-like expression, and an associative operation to
146+combine ``Expr``\s.
147+
148+``DBNum``, ``DBIntegral`` and ``DBFractional``
149+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
150+
151+These type classes are used to present a familiar numeric type hierarchy for
152+Haskell programmers.
153+
154+``DBNum``
155+ This class indicates that a type supports the ``+``, ``-``, and ``*``
156+ operators, along with the ``abs()``, ``negate()`` and ``sign()`` functions.
157+ Database types that are instances of ``DBNum`` allow ``Num (Expr a)`` to be
158+ used (allowing you to combine expressions with Haskell's normal ``+``
159+ function).
160+
161+``DBIntegral``
162+ If a type is an instance of ``DBIntegral``, it means that the type stores
163+ integral (whole) numbers. The ``Rel8.Expr.Num`` module provides familiar
164+ ``Expr`` functions like ``fromIntegral`` to convert between types.
165+
166+``DBFractional``
167+ If a type is an instance of ``DBFraction``, it means that the type supports
168+ the ``/`` operator, and literals can be created via Haskell's ``Rational``
169+ type class. This type class provides the ``Fracitonal (Expr a)`` instance.
170+
171+``DBString``
172+^^^^^^^^^^^^
173+
174+This type class indicates that a database type supports the ``string_agg()``
175+aggregation function.
docs/concepts/expr.rstnew file+74
@@ -0,0 +1,74 @@
1+``Expr`` and ``Sql``
2+====================
3+
4+``Expr``
5+--------
6+
7+Now that we've seen how types are bridged between a database and Haskell via
8+``DBType``, we can start looking at how expressions are modelled. In Rel8, any
9+expression will be a value of the form ``Expr a``, where ``a`` is the type of
10+the expression. For example, the SQL expression ``user.id = 42`` is an ``Expr
11+Bool``, and the subexpressions ``user.id`` and ``42`` might be ``Expr
12+UserId``\s.
13+
14+``Expr``\s are usually created by combining other ``Expr``\s together, like
15+using numeric operations like `+` and `*`, or by quoting Haskell values into
16+queries with ``lit``. Continuing with the example of ``user.id = 42``, we can
17+write this in Rel8 as::
18+
19+ userId ==. lit (UserId 42)
20+
21+Here it's assumed that a ``userId :: Expr UserId`` expression is already in
22+scope, and we can compare that against another ``Expr UserId`` using the ``==.``
23+operator (which is like Haskell's normal ``==`` operator, but lifted to work on
24+``Expr``). The expression ``lit (UserId 42)`` quotes the Haskell term ``UserId
25+42`` literally as the SQL expression ``42``. This particular encoding is chosen
26+because ``UserId`` is simply a ``newtype`` around ``Int64``.
27+
28+``null``
29+--------
30+
31+So far we've only talked about ``DBType``, which represents database types
32+*excluding* ``null``. Rel8 chooses this encoding because ``null`` is rather
33+special in SQL, and doesn't really constitute a distinct type. For example,
34+there is no SQL notion of "stacking" nulls - which is to say a type like ``Maybe
35+(Maybe UserId))`` has no real analogous type in SQL.
36+
37+Of course, as ``null`` is pervasive in SQL queries, Rel8 does support ``null`` -
38+simply wrap up your type in ``Maybe``. ``Nothing`` will be translated as
39+``null``, and ``Just`` is used to represent non-null values.
40+
41+Rel8 comes with a set of functions to work with ``null`` values thash should
42+feel familiar to Haskell programmers:
43+
44+* ``null`` creates null values (you can also use ``lit Nothing``).
45+* ``nullify`` turns an ``Expr a`` into a ``Expr (Maybe a)`` (like ``Just``).
46+* ``nullable`` allows you to eliminate null values, like the ``maybe`` function.
47+* ``isNull`` and ``isNonNull`` work like ``isNothing`` and ``isJust``,
48+ respectively.
49+* ``mapNullable`` is like ``fmap`` for ``Maybe``, and allows you to map over
50+ non-null values.
51+* ``liftOpNullable`` is like ``liftA2`` for ``Maybe``, and allows you to combine
52+ expressions together, given a way to combine non-null expressions.
53+
54+``SQL`` and null-polymorphic expressions
55+----------------------------------------
56+
57+Through the API reference documentation for Rel8, you might encounter the
58+``Sql`` type class. For example, if we look at the type of ``litExpr``, we
59+have::
60+
61+ litExpr :: Sql DBType a => a -> Expr a
62+
63+Here ``Sql DBType a`` means that ``a`` can either be literally a type that has
64+an instance of ``DBType`` (like ``UserId`` or ``Bool``), *or* that same type
65+wrapped in ``Maybe`` (so ``Maybe UserId`` or ``Maybe Bool``). ``Maybe`` here
66+encodes the SQL concept of ``null``.
67+
68+Some functions work regardless of whether or not a value is null, and in these
69+cases you'll see ``Sql DBType a``. ``Sql`` can be used with any ``DBType``
70+subtype. For example, the type of ``div`` is::
71+
72+ div :: Sql DBIntegral a => Expr a -> Expr a -> Expr a
73+
74+Which means ``div`` works on any ``DBIntegral a``, including ``Maybe a``.
docs/concepts/insert.rstnew file+181
@@ -0,0 +1,181 @@
1+``INSERT``, ``UPDATE`` and ``DELETE``
2+=====================================
3+
4+While the majority of Rel8 is about building and executing ``SELECT``
5+statement, Rel8 also has support for ``INSERT``, ``UPDATE`` and ``DELETE``.
6+These statements are all executed using the ``insert``, ``update`` and
7+``delete`` functions, all of which take a record of parameters.
8+
9+.. note::
10+
11+ This part of Rel8's API uses the ``DuplicateRecordFields`` language
12+ extension. In code that needs to use this API, you should also enable this
13+ language extension, or you may get errors about ambiguous field names.
14+
15+``DELETE``
16+----------
17+
18+To perform a ``DELETE`` statement, construct a ``Delete`` value and execute it
19+using ``delete``. ``Delete`` takes:
20+
21+``from``
22+ The ``TableSchema`` for the table to delete rows from.
23+
24+``using``
25+ This is a simple ``Query`` that forms the ``USING`` clause of the ``DELETE``
26+ statement. This can be used to join against other tables, and the results
27+ can be referenced in the ``deleteWhere`` parameter. For simple ``DELETE``\s
28+ where you don't need to do this, you can set ``using = pure ()``.
29+
30+``deleteWhere``
31+ The ``WHERE`` clause of the ``DELETE`` statement. This is a function that
32+ takes two inputs: the result of the ``using`` query, and the current value
33+ of the row.
34+
35+``returning``
36+ What to return - see :ref:`returning`.
37+
38+``UPDATE``
39+----------
40+
41+To perform a ``UPDATE`` statement, construct a ``Update`` value and execute it
42+using ``update``. ``Update`` takes:
43+
44+``target``
45+ The ``TableSchema`` for the table to update rows in.
46+
47+``from``
48+ This is a simple ``Query`` that forms the ``FROM`` clause of the ``UPDATE``
49+ statement. This can be used to join against other tables, and the results
50+ can be referenced in the ``set`` and ``updateWhere`` parameters. For simple
51+ ``UPDATE``\s where you don't need to do this, you can set ``from = pure ()``.
52+
53+``set``
54+ A row to row transformation function, indicating how to update selected rows.
55+ This function takes rows of the same shape as ``target`` but in the ``Expr``
56+ context. One way to write this function is to use record update syntax::
57+
58+ set = \from row -> row { rowName = "new name" }
59+
60+``updateWhere``
61+ The ``WHERE`` clause of the ``UPDATE`` statement. This is a function that
62+ takes two inputs: the result of the ``from`` query, and the current value of
63+ the row.
64+
65+``returning``
66+ What to return - see :ref:`returning`.
67+
68+``INSERT``
69+----------
70+
71+To perform a ``INSERT`` statement, construct a ``Insert`` value and execute it
72+using ``insert``. ``Insert`` takes:
73+
74+``into``
75+ The ``TableSchema`` for the table to insert rows into.
76+
77+``rows``
78+ The rows to insert. These are the same as ``into``, but in the ``Expr``
79+ context. You can construct rows from their individual fields::
80+
81+ rows = values [ MyTable { myTableA = lit "A", myTableB = lit 42 }
82+
83+ or you can use ``lit`` on a table value in the ``Result`` context::
84+
85+ rows = values [ lit MyTable { myTableA = "A", myTableB = 42 }
86+
87+``onConflict``
88+ What should happen if an insert clashes with rows that already exist. This
89+ corresponds to PostgreSQL's ``ON CONFLICT`` clause. You can specify:
90+
91+ ``Abort``
92+ PostgreSQL should abort the ``INSERT`` with an exception
93+
94+ ``DoNothing``
95+ PostgreSQL should not insert the duplicate rows.
96+
97+ ``DoUpdate``
98+ PostgreSQL should instead try to update any existing rows that conflict
99+ with rows proposed for insertion.
100+
101+``returning``
102+ What to return - see :ref:`returning`.
103+
104+.. _returning:
105+
106+``RETURNING``
107+-------------
108+
109+PostgreSQL has the ability to return extra information after a ``DELETE``,
110+``INSERT`` or ``UPDATE`` statement by attaching a ``RETURNING`` clause. A common
111+use of this clause is to return any automatically generated sequence values for
112+primary key columns. Rel8 supports ``RETURNING`` clauses by filling in the
113+``returning`` field and specifying a ``Projection``. A ``Projection`` is a row
114+to row transformation, allowing you to project out a subset of fields.
115+
116+For example, if we are inserting orders, we might want the order ids returned::
117+
118+ insert Insert
119+ { into = orderSchema
120+ , rows = values [ order ]
121+ , onConflict = Abort
122+ , returning = Projection orderId
123+ }
124+
125+If we don't want to return anything, we can use ``pure ()``::
126+
127+ insert Insert
128+ { into = orderSchema
129+ , rows = values [ order ]
130+ , onConflict = Abort
131+ , returning = pure ()
132+ }
133+
134+Default values
135+--------------
136+
137+It is fairly common to define tables with default values. While Rel8 does not
138+have specific functionality for ``DEFAULT``, there are a few options:
139+
140+``unsafeDefault``
141+~~~~~~~~~~~~~~~~~~~~~~~~~~~
142+
143+Rel8 does not have any special support for ``DEFAULT``. If you need to use
144+default column values in inserts, you can use ``unsafeDefault`` to
145+construct the ``DEFAULT`` expression::
146+
147+ insert Insert
148+ { into = orderSchema
149+ , rows = values [ Order { orderId = unsafeDefault, ... } ]
150+ , onConflict = Abort
151+ , returning = Projection orderId
152+ }
153+
154+.. warning::
155+ As the name suggests, this is an unsafe operation. In particular, Rel8 is not
156+ able to prove that this column does have a default value, so it may be
157+ possible to introduce a runtime error. Furthermore, ``DEFAULT`` is fairly
158+ special in SQL, and cannot be combined like other expressions. For example,
159+ the innocuous expression::
160+
161+ unsafeDefault + 1
162+
163+ will lead to a runtime crash.
164+
165+Reimplement default values in Rel8
166+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
167+
168+If you only need to access default values in Rel8, another option is to specify
169+them in Rel8, rather than in your database schema.
170+
171+.. hint::
172+ A common default value for primary keys is to use `nextval` to obtain the
173+ next value from a sequence. This can be done in Rel8 by using the ``nextval``
174+ function::
175+
176+ insert Insert
177+ { into = orderSchema
178+ , rows = values [ Order { orderId = nextval "order_id_seq", ... } ]
179+ , onConflict = Abort
180+ , returning = Projection orderId
181+ }
docs/concepts/queries.rstnew file+274
@@ -0,0 +1,274 @@
1+Writing queries with ``Query``
2+==============================
3+
4+To fetch data from a database, Rel8 allows you to write ``SELECT`` queries using
5+the ``Query`` monad. While this monad might look a little different from
6+ordinary SQL, it is equal in expressivity, but due to Haskell's ``do`` notation
7+we get to benefit from all the means of abstraction available.
8+
9+Understanding the ``Query`` monad
10+---------------------------------
11+
12+Before we look at special functions for working with ``Query``, we'll first take
13+a moment to understand how the ``Query`` monad works. First, what does the type
14+``Query a`` *mean*? To be a ``Query a`` means to be a SQL ``SELECT`` query that
15+selects rows of type ``a``. Usually ``a`` will be an instance of ``Table Expr``,
16+such as ``Expr Text``, or maybe ``BlogPostComment Expr``.
17+
18+As ``Query`` is an instance of ``Monad`` means that we already have three
19+familiar APIs to work with: ``Functor``, ``Applicative``, and ``Monad``.
20+
21+``Functor Query``
22+^^^^^^^^^^^^^^^^^
23+
24+The ``Functor`` instance gives us access to ``fmap``, and its type is::
25+
26+ fmap :: (a -> b) -> Query a -> Query b
27+
28+``fmap`` uniformly transforms rows of one type into rows of another type. In
29+SQL, this is corresponds to a *projection*. For example, if we have a ``Query
30+(User Expr)``, we might do ``fmap userId`` to transform this into a ``Query
31+(Expr UserId)``.
32+
33+``Applicative Query``
34+^^^^^^^^^^^^^^^^^^^^^
35+
36+The ``Applicative`` instance for ``Query`` gives us::
37+
38+ pure :: a -> Query a
39+ (<*>) :: Query (a -> b) -> Query a -> Query b
40+
41+``pure`` constructs a ``Query`` that returns exactly one row - a row containing
42+the ``a`` that was given. This might seem fairly pointless, but it's an
43+important ``Query`` when compared with ``(<*>)``. The ``<*>`` combines two
44+``Query``\s by taking their *cartesian product*, followed by a projection that
45+combines each row into a new row.
46+
47+One example of using the ``Applicative`` operators is to combine two ``Query``\s
48+into a tuple::
49+
50+ pure (,) <*> queryA <*> queryB
51+
52+``Monad Query``
53+^^^^^^^^^^^^^^^
54+
55+The final type class to discuss is ``Monad Query``. ``Monad Query`` has two
56+methods::
57+
58+ return :: a -> Query a
59+ (>>=) :: Query a -> (a -> Query b) -> Query b
60+
61+``return`` is the same ``pure``, so we won't discuss this further. The much more
62+interesting operation is ``>>=`` - commonly referred to as "bind". This operator
63+allows you to *extend* a ``Query`` with a new query. In SQL this is also similar
64+to a cartesian product, but uses the ``LATERAL`` modifier to allow the second
65+query to refer to columns from the first.
66+
67+This extension operator allows you to expand each row in the first query into
68+zero, one, or many rows, according to the given function. For example, if we
69+have a database of orders, we might write::
70+
71+ getAllOrders >>= \order -> getUserById (orderUserId order)
72+
73+This ``Query`` will return, for each ``Order``, the ``User`` who placed that
74+order. In this case, this is a one-to-one relationship, so we get back exactly
75+as many rows as there are orders.
76+
77+Going in the other direction, we have::
78+
79+ getAllUsers >>= \user -> getOrdersForUser (userId user)
80+
81+This is a different query, as we start by fetching all ``User``\s, and for each
82+user find all ``Order``\s they have placed. This ``Query`` has a different
83+cardinality, as we're following a one-to-many relationship: any ``User`` may
84+have zero, one, or many orders.
85+
86+Haskell has special syntax for working with monads - ``do`` notation. ``do``
87+notation allows you to write these queries in a simpler form, where we don't
88+have to introduce functions. Expanding on the latter query, we could write::
89+
90+ do user <- getAllUsers
91+ order <- getOrdersForUser user
92+ return (user, order)
93+
94+Now we have a query that, for each ``User``, fetches all orders for that user.
95+The final ``return`` means that for each ``User`` and ``Order``, we'll return a
96+single row.
97+
98+Selecting rows from tables
99+--------------------------
100+
101+With the more theoretical side of ``Query`` considered, we can start looking at
102+the more pragmatic side, and how ``Query`` can express some common SQL idioms.
103+
104+First, one of the most common operations is to select all rows from a *base
105+table*. In SQL, this is a ``SELECT * FROM x`` query, and in Rel8 we use ``each``
106+with a ``TableSchema``.
107+
108+Limit and offset
109+----------------
110+
111+The SQL ``LIMIT`` and ``OFFSET`` keywords are available in Rel8 as ``limit``
112+and ``offset``. Note that, like SQL, the order of these operations matters.
113+Usually, the correct thing to do is to first apply an offset with ``offset``,
114+and then use ``limit`` to limit the number of rows returned::
115+
116+ limit n . offset m . orderBy anOrdering
117+
118+These operations are similar to Haskell's ``take`` and ``drop`` operations.
119+
120+Filtering queries
121+-----------------
122+
123+Rel8 offers a few different ways to filter the rows selected by a query.
124+Perhaps the most familiar operation is to apply a ``WHERE`` clause to a query.
125+In Rel8, this is done using ``where_``, which takes any ``Expr Bool``, and
126+returns rows where that ``Expr`` is true. For example, to select all public
127+blog posts, we could write::
128+
129+ blogPost <- each blogPostSchema
130+ where_ $ blogPostIsPublic blogPost
131+
132+An alternative way to write ``WHERE`` clauses is to use ``filter``. This
133+operator is similar to the ``guard`` function in ``Control.Monad``, but also
134+returns the tested row. This allows us to easily chain a filtering operation on
135+a query. The above query could thus be written as::
136+
137+ blogPost <- filter blogPostIsPublic =<< each blogPostSchema
138+
139+``where_`` and ``filter`` allow you to filter rows based on an expression, but
140+sometimes we want to filter based on another query. For this, Rel8 offers
141+``present`` and ``absent``. For example, if all blog posts have a
142+list of tags, we could use ``present`` to find all blog posts that have been
143+tagged as "Haskell"::
144+
145+ blogPost <- each blogPostSchema
146+ present do
147+ filter (("Haskell" ==.) . tagName) =<< tagFromBlogPost blogPost
148+
149+Notice that this example uses ``present`` with a query that itself uses
150+``filter``. For each blog post, ``present`` causes that row to be selected
151+only if the associated query finds a tag for that blog post with the ``tagName``
152+"Haskell".
153+
154+Like ``filter`` there is also a chaining variant of ``present`` - ``with``.
155+We could rewrite the above query using ``with`` as::
156+
157+ haskellBlogPost <-
158+ each blogPostSchema >>=
159+ with (filter (("Haskell" ==.) . tagName) <=< tagFromBlogPost)
160+
161+Inner joins
162+-----------
163+
164+Inner joins are SQL queries of the form ``SELECT .. FROM x JOIN y ON ..``. Rel8
165+doesn't offer a special function for these queries, as the same query can be
166+expressed by selecting from two tables (this is called taking the *cartesian
167+product* of two queries) and then filtering the result.
168+
169+If we wanted to join each blog post with the author of the blog post, we would
170+write the SQL::
171+
172+ SELECT * FROM blog_post JOIN author ON author.id = blog_post.id
173+
174+The alternative way to write this query with ``WHERE`` is::
175+
176+ SELECT * FROM blog_post, author WHERE author.id = blog_post.id
177+
178+and this query can be written in Rel8 as::
179+
180+ blogPost <- each blogPostSchema
181+ author <- each authorSchema
182+ where_ $ blogPostAuthorId blogPost ==. authorId author
183+
184+.. hint::
185+
186+ A good pattern to adopt is to abstract out these joins as functions. A
187+ suggested way to write the above would be to extract out an "author for blog
188+ post" function::
189+
190+ blogPost <- each blogPostSchema
191+ author <- authorForBlogPost blogPost
192+
193+ where::
194+
195+ authorForBlogPost :: BlogPost Expr -> Query (Author Expr)
196+ authorForBlogPost blogPost =
197+ filter ((blogPostAuthorId blogPost ==.) . authorId) =<<
198+ each authorSchema
199+
200+ While this is a little more code over all, in our experience this style
201+ dramatically increases the readability of queries using joins.
202+
203+Left (outer) joins with ``optional``
204+------------------------------------
205+
206+A left join is like an inner join, but allows for the possibility of the join to
207+"fail". You use left joins when you want to join optional information against a
208+row.
209+
210+In Rel8, a ``LEFT JOIN`` is introduced by converting an inner join with
211+``optional``. While this approach might seem a little foreign at first, it has a
212+strong similarity with the ``Control.Applicative.optional`` function, and allows
213+you to reuse previous code.
214+
215+To see an example of this, let's assume that we want to get the latest comment
216+for each blog post. Not all blog posts are popular though, so some blog posts
217+might have no comment at all. To write this in Rel8, we could write::
218+
219+ blogPost <- each blogPostSchema
220+
221+ latestComment <-
222+ optional $ limit 1 $
223+ orderBy (commentCreatedAt >$< desc) $
224+ commentsForBlogPost blogPost
225+
226+``optional`` will transform a ``Query a`` into a ``Query (MaybeTable a)``.
227+``MaybeTable`` is similar to the normal ``Maybe`` data type in Haskell, and
228+represents the choice between a ``justTable x`` and a ``nothingTable`` (like
229+``Just x`` and ``Nothing``, respectively). When you execute a query containing
230+``MaybeTable x`` with ``select``, Rel8 will return ``Maybe x``. ``MaybeTable``
231+comes with a library of routines, similar to the functions that can be used to
232+operate on ``Maybe``. For more details, see the API documentation.
233+
234+.. hint::
235+
236+ ``optional`` converts an inner join into a ``LEFT JOIN``, but you can also go
237+ the other way - and turn a ``LEFT JOIN`` back into an inner join! To do this,
238+ you can use ``catMaybeTable``, which will select only the rows when the left
239+ join was successful.
240+
241+Ordering results
242+----------------
243+
244+Rel8 supports ordering the results returned by a ``Query``, using SQL's ``ORDER
245+BY`` syntax. To specify an ordering, you use ``orderBy`` and supply an
246+appropriate ``Order`` value.
247+
248+An ``Order`` is built by combining the order of individual columns, each of
249+which can be either ascending or descending. To order a single column, you
250+combine ``asc`` or ``desc`` with ``Order``\s *contravariant* interface. For
251+example, if we have a table with a ``orderId`` column, we can order a ``Query
252+(Order Expr)`` by ``orderId`` with::
253+
254+ orderBy (orderId >$< asc)
255+
256+To order by multiple columns, combine the individual orders with ``Order``\s
257+``Monoid`` instance. We could extend the above example to order by the order
258+date first (with the most recent orders first) with::
259+
260+ orderBy (mconcat [orderDate >$< desc, orderId >$< asc])
261+
262+Aggregating queries
263+-------------------
264+
265+.. todo::
266+
267+ Write this
268+
269+Set operations
270+--------------
271+
272+.. todo::
273+
274+ Write this
docs/concepts/tables.rstnew file+60
@@ -0,0 +1,60 @@
1+Tables
2+======
3+
4+So far we've seen that ``DBType`` bridges Haskell types to database types, and
5+``Expr`` lets us write SQL expressions using these types. The next concept is to
6+understand how tables are mapped into Rel8.
7+
8+In Rel8, we understand a table to be a list of columns. Each column has some
9+associated metadata - a column has a type, but it also has information as to
10+whether it can store ``null``, the name of the column, and whether this column
11+has a default value. All of this metadata can be configured when you define
12+custom table types, but first we'll look at some built in tables.
13+
14+``Expr`` is a single-column table
15+---------------------------------
16+
17+Any time you have an ``Expr``, you also have a table. All ``Expr``\s are tables
18+that consist of exactly one column. This means that whenever a table is
19+expected, you can usually use an ``Expr`` as well.
20+
21+Tuples combine tables
22+---------------------
23+
24+You can use Haskell's normal tuple syntax to combine tables into larger tables.
25+Now that we know that an ``Expr`` is a table with one column, we can use tuples
26+to build larger tables. For example, if we have ``userId :: Expr UserId`` and a
27+``name :: Expr Text``, we can pair these together as ``(userId, name) :: (Expr
28+UserId, Expr Text)``.
29+
30+Rel8 supports tuples with two, three, four and five elements. Beyond that, we
31+suggest writing a custom table type (though you can also nest tuples).
32+
33+Custom table types
34+------------------
35+
36+The primary way to define a table in Rel8 is to use the higher-kinded data
37+pattern. Rel8 advocates this system because it means you can define your data
38+type once, but use it in the context of Haskell expressions (for example, to
39+serialize it as JSON to use as a REST API call response type), and also within
40+Rel8 queries. This allows developers to share their understanding of a type in
41+multiple domains, while also reducing the amount of code that has to be written
42+and maintained.
43+
44+To define a custom table using this pattern, you define a Haskell data type that
45+has a single parameter (conventionally called ``f``). Next, we suggest using
46+record syntax to define the fields of your data type, and for each field use the
47+``Column`` type family to define the type of the column. Once all fields have
48+been defined, you can bridge this type with Rel8 by deriving ``Generic`` and
49+``Rel8able`` instance.
50+
51+A typical table definition might look like this::
52+
53+ data User f = User
54+ { userId :: Column f UserId
55+ , userName :: Column f Text
56+ , userCreatedAt :: Column f UTCTime
57+ , userEmail :: Column f (Maybe EmailAddress)
58+ }
59+ deriving stock (Generic)
60+ deriving anyclass (Rel8able)
docs/conf.pynew file+36
@@ -0,0 +1,36 @@
1+import sys
2+import os
3+import sphinx_rtd_theme
4+
5+# Support for :base-ref:, etc.
6+sys.path.insert(0, os.path.abspath('.'))
7+
8+version = "1.0.0"
9+
10+extensions = ['sphinx.ext.extlinks', 'sphinx.ext.todo', 'sphinx_rtd_theme']
11+
12+templates_path = ['_templates']
13+source_suffix = '.rst'
14+source_encoding = 'utf-8-sig'
15+master_doc = 'index'
16+
17+project = u'Rel8'
18+copyright = u'2021 CircuitHub'
19+release = version
20+
21+highlight_language = 'haskell'
22+primary_domain = 'haskell'
23+
24+exclude_patterns = ['.build', "*.gen.rst"]
25+
26+html_theme = 'sphinx_rtd_theme'
27+html_theme_options = {
28+ 'logo_only': True,
29+ 'navigation_depth': 5,
30+}
31+html_context = {}
32+
33+# on_rtd is whether we are on readthedocs.org, this line of code grabbed from docs.readthedocs.org
34+on_rtd = os.environ.get('READTHEDOCS', None) == 'True'
35+
36+todo_include_todos = True
docs/cookbook.rstnew file+169
@@ -0,0 +1,169 @@
1+Cookbook
2+========
3+
4+This cookbook exists to help you easily form Rel8 queries. It's main purpose is
5+to help those familiar with SQL to translate their queries into Rel8
6+``Query``\s.
7+
8+``SELECT * FROM table``
9+-----------------------
10+
11+To select from a table, use ``each``.
12+
13+Inner joins
14+-----------
15+
16+To perform an inner join against two queries, use ``where_`` with a join
17+condition. For example, the following SQL:
18+
19+.. code-block:: sql
20+
21+ SELECT * FROM table_a JOIN table_b ON table_a.x = table_b.y
22+
23+can be written as::
24+
25+ myQuery = do
26+ a <- each tableA
27+ b <- each tableB
28+ where_ $ tableAX a ==. tableBY b
29+
30+Left (outer) joins
31+------------------
32+
33+A ``LEFT JOIN`` query is performed by using ``optional``.
34+
35+For example, the query:
36+
37+.. code-block:: sql
38+
39+ SELECT * FROM table_a LEFT JOIN table_b ON table_a.x = table_b.y
40+
41+can be written as::
42+
43+ myQuery = do
44+ a <- each tableA
45+
46+ maybeB <- optional do
47+ b <- each tableB
48+ where_ $ tableAX a ==. tableBY b
49+
50+ return (a, maybeB)
51+
52+Note that ``maybeB`` here will be a ``MaybeTable``, which is the Rel8
53+``Query``-equivalent of ``Maybe``. This allows you to observe if a left join
54+has succeeded or failed.
55+
56+Ordering results
57+----------------
58+
59+A ``Query`` by default has no ordering - just like in SQL. If you rows back in
60+a certain order, you can use ``orderBy`` with an ``Order``.
61+
62+For example, the query:
63+
64+.. code-block:: sql
65+
66+ SELECT * FROM my_table ORDER BY my_table.id ASC, my_table.x DESC NULLS FIRST
67+
68+can be written as::
69+
70+ myQuery =
71+ orderBy (mconcat [ myTableId >$< asc, myTableX >$< nullsFirst desc ]) $
72+ each myTableSchema
73+
74+Note that we use ``>$<`` (from ``Data.Functor.Contravariant``) to select table
75+columns, and we can use ``mconcat`` to combine orderings.
76+
77+If all columns of a table have an ordering, you can also use ``ascTable`` and
78+``descTable``. For example::
79+
80+ myQuery = orderBy ascTable $ each myTableSchema
81+
82+Aggregations
83+------------
84+
85+Aggregations in Rel8 work by using ``aggregate``, which takes a ``Query
86+(Aggregate a)`` and gives you back a ``Query a``.
87+
88+The following query:
89+
90+.. code-block:: sql
91+
92+ SELECT sum(foo), count(distinct bar) FROM table_a
93+
94+can be written as::
95+
96+ myQuery = aggregate do
97+ a <- each tableA
98+ return $ liftF2 (,) (sum (foo a)) (countDistinct (bar a))
99+
100+where ``liftF2`` comes from ``Data.Functor.Apply`` from the ``semigroupoids``
101+library.
102+
103+Combining aggregations
104+----------------------
105+
106+As ``Aggregate`` is an instance of ``Apply`` (which is very similar to
107+``Applicative``), individual aggregations can be combined. For example, one way
108+to take the average rating would be to write the query:
109+
110+.. code-block:: sql
111+
112+ SELECT sum(rating.score) / count(rating.score) FROM rating
113+
114+In Rel8, we can write this as::
115+
116+ myQuery = aggregate do
117+ rating <- each ratingSchema
118+ return $ liftF2 (/) (sum (score rating)) (count (score rating))
119+
120+You can also use ``RebindableSyntax`` and ``ApplicativeDo``::
121+
122+ {-# language ApplicativeDo, RebindableSyntax #-}
123+
124+ import Data.Functor.Apply ((<.>))
125+
126+ myQuery = aggregate do
127+ rating <- each ratingSchema
128+ return do
129+ scoreSum <- sum (score rating)
130+ numberOfRatings <- count (score rating)
131+ return (scoreSum / numberOfRatings)
132+ where (<*>) = (<.>)
133+
134+For large aggregations, this can often make queries easier to read.
135+
136+Tree-like queries
137+-----------------
138+
139+Rel8 has a fairly unique feature in that it's able to return not just lists of
140+rows, but can also return *tree*\s.
141+
142+To understand what this means, we'll consider a small example query for blog
143+posts. We want our query to return:
144+
145+1. The latest 5 blog posts that have at least one tag each.
146+2. For each blog post, all tags.
147+3. For each blog post, the latest 3 comments if they exist.
148+
149+In Rel8, we can write this query as::
150+
151+ latestBlogPosts = do
152+ post <- each postSchema
153+
154+ -- Returns a `NonEmptyTable a` which ends up as a `Data.List.NonEmpty a` after the query is run
155+ tags <- some $ do
156+ tag <- each tagSchema
157+ where_ (tagPostId tag ==. postId post)
158+ return (tagName tag)
159+
160+ -- Returns a `ListTable a` which ends up as a `[a]` after the query is run
161+ latestComments <-
162+ many $
163+ limit 3 $
164+ orderBy (commentCreatedAt >$< desc) do
165+ comment <- each commentSchema
166+ where_ (commentPostId comment ==. postId post)
167+
168+ return (post, tags, latestComments)
169+
docs/index.rstnew file+53
@@ -0,0 +1,53 @@
1+Welcome to Rel8!
2+================
3+
4+Welcome to Rel8! Rel8 is a Haskell library for interacting with PostgreSQL
5+databases, built on top of the fantastic `Opaleye
6+<https://hackage.haskell.org/package/opaleye>`_ library.
7+
8+The main objectives of Rel8 are:
9+
10+* *Conciseness*: Users using Rel8 should not need to write boiler-plate code.
11+ By using expressive types, we can provide sufficient information for the
12+ compiler to infer code whenever possible.
13+
14+* *Inferrable*: Despite using a lot of type level magic, Rel8 aims to have
15+ excellent and predictable type inference.
16+
17+* *Familiar*: writing Rel8 queries should feel like normal Haskell programming.
18+
19+.. toctree::
20+ :caption: Getting Started
21+ :maxdepth: 2
22+
23+ tutorial
24+
25+.. toctree::
26+ :caption: Rel8 concepts
27+ :maxdepth: 2
28+
29+ concepts/dbtype
30+ concepts/expr
31+ concepts/tables
32+ concepts/queries
33+ concepts/insert
34+
35+.. toctree::
36+ :caption: Tips and tricks
37+ :maxdepth: 1
38+
39+ cookbook
40+
41+
42+More Resources
43+==============
44+
45+* The `Haskell API documentation <https://hackage.haskell.org/package/rel8>`_
46+ describes how individual functions are types are to be used.
47+
48+* If you have a question about how to use Rel8, feel free to open a `GitHub
49+ discussion <https://github.com/circuithub/rel8/discussions>`_.
50+
51+* If you think you've found a bug, confusing behavior, or have a feature
52+ request, please raise an issue at `Rel8's issue tracker
53+ <https://github.com/circuithub/rel8>`_.
docs/requirements.txtnew file+4
@@ -0,0 +1,4 @@
1+docutils == 0.16.*
2+sphinx == 3.5.*
3+sphinx_rtd_theme
4+
docs/tutorial.rstnew file+387
@@ -0,0 +1,387 @@
1+.. highlight:: haskell
2+
3+Getting Started
4+===============
5+
6+In this section, we'll take a look at using Rel8 to work with a small database
7+for Haskell packages. We'll take a look at idiomatic usage of Rel8, mapping
8+tables to Haskell, and then look at writing some simple queries.
9+
10+Before we get started, we'll be using the following language extensions and
11+imports throughout this guide::
12+
13+ {-# language BlockArguments #-}
14+ {-# language DeriveAnyClass #-}
15+ {-# language DeriveGeneric #-}
16+ {-# language DerivingStrategies #-}
17+ {-# language DerivingVia #-}
18+ {-# language DuplicateRecordFields #-}
19+ {-# language GeneralizedNewtypeDeriving #-}
20+ {-# language OverloadedStrings #-}
21+ {-# language StandaloneDeriving #-}
22+ {-# language TypeApplications #-}
23+ {-# language TypeFamilies #-}
24+
25+ import Prelude
26+ import Rel8
27+
28+The Example Schema
29+------------------
30+
31+Before we start writing any Haskell, let's take a look at the schema we'll work
32+with. The `author` table has three columns:
33+
34++-----------------+-------------+----------+
35+| Column Name | Type | Nullable |
36++=================+=============+==========+
37+| ``author_id`` | ``integer`` | not null |
38++-----------------+-------------+----------+
39+| ``name`` | ``text`` | not null |
40++-----------------+-------------+----------+
41+| ``url`` | ``text`` | |
42++-----------------+-------------+----------+
43+
44+and the `project` table has two:
45+
46++-----------------+-------------+----------+
47+| Column Name | Type | Nullable |
48++=================+=============+==========+
49+| ``author_id`` | ``integer`` | not null |
50++-----------------+-------------+----------+
51+| ``name`` | ``text`` | not null |
52++-----------------+-------------+----------+
53+
54+A ``project`` always has an ``author``, but not all ``author``\s have projects.
55+Each ``author`` has a name and (maybe) an associated website, and each project
56+has a name.
57+
58+Mapping Schemas to Haskell
59+--------------------------
60+
61+Now that we've seen our schema, we can begin writing a mapping in Rel8. The
62+idiomatic way to map a table is to use a record that is parameterised what Rel8
63+calls an *interpretation functor*, and to define each field with ``Column``.
64+For this type to be usable with Rel8 we need it to be an instance of
65+``Rel8able``, which can be derived with a combination of ``DeriveAnyClass`` and
66+``DeriveGeneric`` language extensions.
67+
68+Following these steps for ``author``, we have::
69+
70+ data Author f = Author
71+ { authorId :: Column f Int64
72+ , name :: Column f Text
73+ , url :: Column f (Maybe Text)
74+ }
75+ deriving stock (Generic)
76+ deriving anyclass (Rel8able)
77+
78+This is a perfectly reasonable definition, but cautious readers might notice a
79+problem - in particular, with the type of the ``authorId`` field. While
80+``Int64`` is correct, it's not the best type. If we had other identifier types
81+in our project, it would be too easy to accidentally mix them up and create
82+nonsensical joins. As Haskell programmers, we often solve this problem by
83+creating ``newtype`` wrappers, and we can also use this technique with Rel8::
84+
85+ newtype AuthorId = AuthorId { toInt64 :: Int64 }
86+ deriving newtype (DBEq, DBType, Eq, Show)
87+
88+Now we can write our final schema mapping. First, the ``author`` table::
89+
90+ data Author f = Author
91+ { authorId :: Column f AuthorId
92+ , authorName :: Column f Text
93+ , authorUrl :: Column f (Maybe Text)
94+ }
95+ deriving stock (Generic)
96+ deriving anyclass (Rel8able)
97+
98+And similarly, the ``project`` table::
99+
100+ data Project f = Project
101+ { projectAuthorId :: Column f AuthorId
102+ , projectName :: Column f Text
103+ }
104+ deriving stock (Generic)
105+ deriving anyclass (Rel8able)
106+
107+To show query results in this documentation, we'll also need ``Show`` instances:
108+Unfortunately these definitions look a bit scary, but they are essentially just
109+``deriving (Show)``::
110+
111+ deriving stock instance f ~ Result => Show (Author f)
112+ deriving stock instance f ~ Result => Show (Project f)
113+
114+These data types describe the structural mapping of the tables, but we also
115+need to specify a ``TableSchema`` for each table. A ``TableSchema`` contains
116+the name of the table and the name of all columns in the table, which will
117+ultimately allow us to ``SELECT`` and ``INSERT`` rows for these tables.
118+
119+To define a ``TableSchema``, we just need to fill construct appropriate
120+``TableSchema`` values. When it comes to the ``tableColumns`` field, we
121+construct values of our data types above, and set each field to the name of the
122+column that it maps to.
123+
124+First, ``authorSchema`` describes the column names of the ``author`` table when
125+associated with the ``Author`` type::
126+
127+ authorSchema :: TableSchema (Author Name)
128+ authorSchema = TableSchema
129+ { name = "author"
130+ , schema = Nothing
131+ , columns = Author
132+ { authorId = "author_id"
133+ , authorName = "name"
134+ , authorUrl = "url"
135+ }
136+ }
137+
138+And likewise for ``project`` and ``Project``::
139+
140+ projectSchema :: TableSchema (Project Name)
141+ projectSchema = TableSchema
142+ { name = "project"
143+ , schema = Nothing
144+ , columns = Project
145+ { projectAuthorId = "author_id"
146+ , projectName = "name"
147+ }
148+ }
149+
150+There is also some generics machinery available if you want to grab the field
151+information from your ``Rel8able`` type::
152+
153+ projectSchema :: TableSchema (Project Name)
154+ projectSchema = TableSchema
155+ { name = "project"
156+ , schema = Nothing
157+ , columns = namesFromLabels @(Project Name)
158+ }
159+
160+This will create a ``TableSchema`` for ``Project`` where every column name
161+corresponds exactly to the name of the field. If you need more flexibility, you
162+can use ``namesFromLabelsWith``, which takes a transformation function.
163+
164+.. note::
165+
166+ You might be wondering why this information isn't in the definitions of
167+ ``Author`` and ``Project`` above. Rel8 decouples ``TableSchema`` from the data
168+ types themselves, as not all tables you define will necessarily have a schema.
169+ For example, Rel8 allows you to define helper types to simplify the types of
170+ queries - these tables only exist at query time, but there is no corresponding
171+ base table. We'll see more on this idea later!
172+
173+With these table definitions, we can now start writing some queries!
174+
175+Writing Queries
176+---------------
177+
178+Simple Queries
179+~~~~~~~~~~~~~~
180+
181+First, we'll take a look at ``SELECT`` statements - usually the bulk of most
182+database heavy applications.
183+
184+In Rel8, ``SELECT`` statements are built using the ``Query`` monad. You can
185+think of this monad like the ordinary ``[]`` (List) monad - but this isn't
186+required knowledge.
187+
188+To start, we'll look at one of the simplest queries possible - a basic ``SELECT
189+* FROM`` statement. To select all rows from a table, we use ``each``, and
190+supply a ``TableSchema``. So to select all ``project`` rows, we can write::
191+
192+ >>> :t each projectSchema
193+ each projectSchema :: Query (Project Expr)
194+
195+Notice that ``each`` gives us a ``Query`` that yields ``Project Expr`` rows. To
196+see what this means, let's have a look at a single field of a ``Project Expr``::
197+
198+ >>> let aProjectExpr = undefined :: Project Expr
199+ >>> :t projectAuthorId aProjectExpr
200+ projectAuthorId aProjectExpr :: Expr AuthorId
201+
202+Recall we defined ``projectAuthorId`` as ``Column f AuthorId``. Now we have
203+``f`` is ``Expr``, and ``Column Expr AuthorId`` reduces to ``Expr AuthorId``.
204+We'll see more about ``Expr`` soon, but you can think of ``Expr a`` as "SQL
205+expressions of type ``a``\".
206+
207+To execute this ``Query``, we pass it to ``select``. This function takes both a
208+database connection (which can be obtained using hasql's ``acquire`` function),
209+and the ``Query`` to run::
210+
211+ >>> Right conn <- acquire "user=postgres"
212+ >>> :t select conn (each projectSchema)
213+ select conn (each projectSchema) :: MonadIO m => m [Project Result]
214+
215+When we ``select`` things containing ``Expr``\s, Rel8 builds a new response
216+table with the ``Result`` interpretation. This means you'll get back plain
217+Haskell values. Studying ``projectAuthorId`` again, we have::
218+
219+ >>> let aProjectResult = undefined :: Project Result
220+ >>> :t projectAuthorId aProjectResult
221+ projectAuthorId aProjectResult :: AuthorId
222+
223+Here ``Column Result AuthorId`` reduces to just ``AuthorId``, with no
224+wrappping type at all.
225+
226+Putting this all together, we can run our first query::
227+
228+ >>> select conn (each projectSchema) >>= mapM_ print
229+ Project {projectAuthorId = 1, projectName = "rel8"}
230+ Project {projectAuthorId = 2, projectName = "aeson"}
231+ Project {projectAuthorId = 2, projectName = "text"}
232+
233+We now know that ``each`` is the equivalent of a ``SELECT *`` query, but
234+sometimes we're only interested in a subset of the columns of a table. To
235+restrict the returned columns, we can specify a projection by using ``Query``\s
236+``Functor`` instance::
237+
238+ >>> select conn $ projectName <$> each projectSchema
239+ ["rel8","aeson","text"]
240+
241+Joins
242+~~~~~
243+
244+Another common operation in relational databases is to take the ``JOIN`` of
245+multiple tables. Rel8 doesn't have a specific join operation, but we can
246+recover the functionality of a join by selecting all rows of two tables, and
247+then using ``where_`` to filter them.
248+
249+To see how this works, first let's look at taking the product of two tables.
250+We can do this by simply calling ``each`` twice, and then returning a tuple of
251+their results::
252+
253+ >>> :{
254+ mapM_ print =<< select conn do
255+ author <- each authorSchema
256+ project <- each projectSchema
257+ return (projectName project, authorName author)
258+ :}
259+ ("rel8","Ollie")
260+ ("rel8","Bryan O'Sullivan")
261+ ("rel8","Emily Pillmore")
262+ ("aeson","Ollie")
263+ ("aeson","Bryan O'Sullivan")
264+ ("aeson","Emily Pillmore")
265+ ("text","Ollie")
266+ ("text","Bryan O'Sullivan")
267+ ("text","Emily Pillmore")
268+
269+This isn't quite right, though, as we have ended up pairing up the wrong
270+projects and authors. To fix this, we can use ``where_`` to restrict the
271+returned rows. We could write::
272+
273+ select conn $ do
274+ author <- each authorSchema
275+ project <- each projectSchema
276+ where_ $ projectAuthorId project ==. authorId author
277+ return (project, author)
278+
279+but doing this every time you need a join can obscure the meaning of the
280+query you're writing. A good practice is to introduce specialised functions
281+for the particular joins in your database. In our case, this would be::
282+
283+ projectsForAuthor :: Author Expr -> Query (Project Expr)
284+ projectsForAuthor a = each projectSchema >>= filter \p ->
285+ projectAuthorId p ==. authorId a
286+
287+Our final query is then::
288+
289+ >>> :{
290+ mapM_ print =<< select conn do
291+ author <- each authorSchema
292+ project <- projectsForAuthor author
293+ return (projectName project, authorName author)
294+ :}
295+ ("rel8","Ollie")
296+ ("aeson","Bryan O'Sullivan")
297+ ("text","Bryan O'Sullivan")
298+
299+Left Joins
300+~~~~~~~~~~
301+
302+Rel8 is also capable of performing ``LEFT JOIN``\s. To perform ``LEFT JOIN``\s,
303+we follow the same approach as before, but use the ``optional`` query
304+transformer to allow for the possibility of the join to fail.
305+
306+In our test database, we can see that there's another author who we haven't
307+seen yet::
308+
309+ >>> select conn $ authorName <$> each authorSchema
310+ ["Ollie","Bryan O'Sullivan","Emily Pillmore"]
311+
312+Emily wasn't returned in our earlier query because - in our database - she
313+doesn't have any registered projects. We can account for this partiality in our
314+original query by wrapping the ``projectsForAuthor`` call with ``optional``::
315+
316+ >>> :{
317+ mapM_ print =<< select conn do
318+ author <- each authorSchema
319+ mproject <- optional $ projectsForAuthor author
320+ return (authorName author, projectName <$> mproject)
321+ :}
322+ ("Ollie",Just "rel8")
323+ ("Bryan O'Sullivan",Just "aeson")
324+ ("Bryan O'Sullivan",Just "text")
325+ ("Emily Pillmore",Nothing)
326+
327+
328+Aggregation
329+~~~~~~~~~~~
330+
331+Aggregations are operations like ``sum`` and ``count`` - operations that reduce
332+multiple rows to single values. To perform aggregations in Rel8, we can use the
333+``aggregate`` function, which takes a ``Query`` of aggregated expressions, runs
334+the aggregation, and returns aggregated rows.
335+
336+To start, let's look at a simple aggregation that tells us how many projects
337+exist:
338+
339+.. todo::
340+
341+ >>> error "TODO"
342+
343+Rel8 is also capable of aggregating multiple rows into a single row by
344+concatenating all rows as a list. This aggregation allows us to break free of
345+the row-orientated nature of SQL and write queries that return tree-like
346+structures. Earlier we saw an example of returning authors with their projects,
347+but the query didn't do a great job of describing the one-to-many relationship
348+between authors and their projects.
349+
350+Let's look again at a query that returns authors and their projects, and
351+focus on the /type/ of that query::
352+
353+ projectsForAuthor a = each projectSchema >>= filter \p ->
354+ projectAuthorId p ==. authorId a
355+
356+ let authorsAndProjects = do
357+ author <- each authorSchema
358+ project <- projectsForAuthor author
359+ return (author, project)
360+ where
361+
362+ >>> :t select conn authorsAndProjects
363+ select conn authorsAndProjects
364+ :: MonadIO m => m [(Author Result, Project Result)]
365+
366+
367+Our query gives us a single list of pairs of authors and projects. However,
368+with our domain knowledge of the schema, this isn't a great type - what we'd
369+rather have is a list of pairs of authors and /lists/ of projects. That is,
370+what we'd like is::
371+
372+ [(Author Result, [Project Result])]
373+
374+This would be a much better type! Rel8 can produce a query with this type by
375+simply wrapping the call to ``projectsForAuthor`` with either ``some`` or
376+``many``. Here we'll use ``many``, which allows for the possibility of an
377+author to have no projects::
378+
379+ >>> :{
380+ mapM_ print =<< select conn do
381+ author <- each authorSchema
382+ projectNames <- many $ projectName <$> projectsForAuthor author
383+ return (authorName author, projectNames)
384+ :}
385+ ("Ollie",["rel8"])
386+ ("Bryan O'Sullivan",["aeson","text"])
387+ ("Emily Pillmore",[])
jobs.nixdeleted−5
@@ -1,5 +0,0 @@
1−let rel8 = (import ./.).hsPkgs.rel8;
2−in {
3− rel8 = rel8.components.library;
4− tests = rel8.checks.tests;
5−}
nix/sources.json+36−36
@@ -1,38 +1,38 @@
1{
1{
2− "haskell.nix": {
2+ "haskell.nix": {
3− "branch": "circuithub",
3+ "branch": "master",
4− "description": "Alternative Haskell Infrastructure for Nixpkgs",
4+ "description": "Alternative Haskell Infrastructure for Nixpkgs",
5− "homepage": "https://input-output-hk.github.io/haskell.nix",
5+ "homepage": "https://input-output-hk.github.io/haskell.nix",
6− "owner": "circuithub",
6+ "owner": "input-output-hk",
7− "repo": "haskell.nix",
7+ "repo": "haskell.nix",
8− "rev": "2902f9b49484a87afb0e1a33b1d88a2c7b8ca0a0",
8+ "rev": "0837156c56cb5350dd9bd84eb424187e00aa1e8a",
9− "sha256": "0a01g5b46z5yaf2mnl415hc4lciwiyqhj22qhgwgwd261w4068iy",
9+ "sha256": "1djmv5a0vfj78csw2cad6nicrs8iqrp928b9b3v4h7lwwhhzliwl",
10− "type": "tarball",
10+ "type": "tarball",
11− "url": "https://github.com/circuithub/haskell.nix/archive/2902f9b49484a87afb0e1a33b1d88a2c7b8ca0a0.tar.gz",
11+ "url": "https://github.com/input-output-hk/haskell.nix/archive/0837156c56cb5350dd9bd84eb424187e00aa1e8a.tar.gz",
12− "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
12+ "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
13− },
13+ },
14− "niv": {
14+ "niv": {
15− "branch": "master",
15+ "branch": "master",
16− "description": "Easy dependency management for Nix projects",
16+ "description": "Easy dependency management for Nix projects",
17− "homepage": "https://github.com/nmattia/niv",
17+ "homepage": "https://github.com/nmattia/niv",
18− "owner": "nmattia",
18+ "owner": "nmattia",
19− "repo": "niv",
19+ "repo": "niv",
20− "rev": "ba57d5a29b4e0f2085917010380ef3ddc3cf380f",
20+ "rev": "acdb1726783637852c01e0ad639ac9cbec28d8c8",
21− "sha256": "1kpsvc53x821cmjg1khvp1nz7906gczq8mp83664cr15h94sh8i4",
21+ "sha256": "1wszl8q70z6wfgkh2dvgmhhry6qp9nar421qq2ifd17hq2jj9ck3",
22− "type": "tarball",
22+ "type": "tarball",
23− "url": "https://github.com/nmattia/niv/archive/ba57d5a29b4e0f2085917010380ef3ddc3cf380f.tar.gz",
23+ "url": "https://github.com/nmattia/niv/archive/acdb1726783637852c01e0ad639ac9cbec28d8c8.tar.gz",
24− "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
24+ "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
25− },
25+ },
26− "nixpkgs": {
26+ "nixpkgs": {
27− "branch": "nixos-20.09",
27+ "branch": "nixos-20.09",
28− "description": "Nix Packages collection",
28+ "description": "Nix Packages collection",
29− "homepage": null,
29+ "homepage": null,
30− "owner": "nixos",
30+ "owner": "nixos",
31− "repo": "nixpkgs",
31+ "repo": "nixpkgs",
32− "rev": "6e7f25001fe6874f7ae271891f709bbf50a22c45",
32+ "rev": "1c1f5649bb9c1b0d98637c8c365228f57126f361",
33− "sha256": "1x04j4351pqiqbpkq6g308mxcvb5aqnwv8l2vmlxkgvq5phzky7z",
33+ "sha256": "0f2nvdijyxfgl5kwyb4465pppd5vkhqxddx6v40k2s0z9jfhj0xl",
34− "type": "tarball",
34+ "type": "tarball",
35− "url": "https://github.com/nixos/nixpkgs/archive/6e7f25001fe6874f7ae271891f709bbf50a22c45.tar.gz",
35+ "url": "https://github.com/nixos/nixpkgs/archive/1c1f5649bb9c1b0d98637c8c365228f57126f361.tar.gz",
36− "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
36+ "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
37− }
37+ }
38}
38}
nix/sources.nix+66−20
@@ -6,25 +6,53 @@ let
6 # The fetchers. fetch_<type> fetches specs of type <type>.
6 # The fetchers. fetch_<type> fetches specs of type <type>.
7 #
7 #
8
8
9− fetch_file = pkgs: spec:
9+ fetch_file = pkgs: name: spec:
10+ let
11+ name' = sanitizeName name + "-src";
12+ in
10− if spec.builtin or true then
13+ if spec.builtin or true then
11− builtins_fetchurl { inherit (spec) url sha256; }
14+ builtins_fetchurl { inherit (spec) url sha256; name = name'; }
12− else
15+ else
13− pkgs.fetchurl { inherit (spec) url sha256; };
16+ pkgs.fetchurl { inherit (spec) url sha256; name = name'; };
14
17
15 fetch_tarball = pkgs: name: spec:
18 fetch_tarball = pkgs: name: spec:
16 let
19 let
17− ok = str: ! builtins.isNull (builtins.match "[a-zA-Z0-9+-._?=]" str);
20+ name' = sanitizeName name + "-src";
18− # sanitize the name, though nix will still fail if name starts with period
19− name' = stringAsChars (x: if ! ok x then "-" else x) "${name}-src";
20 in
21 in
21 if spec.builtin or true then
22 if spec.builtin or true then
22 builtins_fetchTarball { name = name'; inherit (spec) url sha256; }
23 builtins_fetchTarball { name = name'; inherit (spec) url sha256; }
23 else
24 else
24 pkgs.fetchzip { name = name'; inherit (spec) url sha256; };
25 pkgs.fetchzip { name = name'; inherit (spec) url sha256; };
25
26
26− fetch_git = spec:
27+ fetch_git = name: spec:
28+ let
29+ ref =
30+ if spec ? ref then spec.ref else
31+ if spec ? branch then "refs/heads/${spec.branch}" else
32+ if spec ? tag then "refs/tags/${spec.tag}" else
33+ abort "In git source '${name}': Please specify `ref`, `tag` or `branch`!";
34+ submodules = if spec ? submodules then spec.submodules else false;
35+ submoduleArg =
36+ let
37+ nixSupportsSubmodules = builtins.compareVersions builtins.nixVersion "2.4" >= 0;
38+ emptyArgWithWarning =
39+ if submodules == true
40+ then
41+ builtins.trace
42+ (
43+ "The niv input \"${name}\" uses submodules "
44+ + "but your nix's (${builtins.nixVersion}) builtins.fetchGit "
45+ + "does not support them"
46+ )
47+ {}
48+ else {};
49+ in
50+ if nixSupportsSubmodules
51+ then { inherit submodules; }
52+ else emptyArgWithWarning;
53+ in
54+ builtins.fetchGit
27− builtins.fetchGit { url = spec.repo; inherit (spec) rev ref; };
55+ ({ url = spec.repo; inherit (spec) rev; inherit ref; } // submoduleArg);
28
56
29 fetch_local = spec: spec.path;
57 fetch_local = spec: spec.path;
30
58
@@ -40,11 +68,21 @@ let
40 # Various helpers
68 # Various helpers
41 #
69 #
42
70
71+ # https://github.com/NixOS/nixpkgs/pull/83241/files#diff-c6f540a4f3bfa4b0e8b6bafd4cd54e8bR695
72+ sanitizeName = name:
73+ (
74+ concatMapStrings (s: if builtins.isList s then "-" else s)
75+ (
76+ builtins.split "[^[:alnum:]+._?=-]+"
77+ ((x: builtins.elemAt (builtins.match "\\.*(.*)" x) 0) name)
78+ )
79+ );
80+
43 # The set of packages used when specs are fetched using non-builtins.
81 # The set of packages used when specs are fetched using non-builtins.
44− mkPkgs = sources:
82+ mkPkgs = sources: system:
45 let
83 let
46 sourcesNixpkgs =
84 sourcesNixpkgs =
47− import (builtins_fetchTarball { inherit (sources.nixpkgs) url sha256; }) {};
85+ import (builtins_fetchTarball { inherit (sources.nixpkgs) url sha256; }) { inherit system; };
48 hasNixpkgsPath = builtins.any (x: x.prefix == "nixpkgs") builtins.nixPath;
86 hasNixpkgsPath = builtins.any (x: x.prefix == "nixpkgs") builtins.nixPath;
49 hasThisAsNixpkgsPath = <nixpkgs> == ./.;
87 hasThisAsNixpkgsPath = <nixpkgs> == ./.;
50 in
88 in
@@ -64,9 +102,9 @@ let
64
102
65 if ! builtins.hasAttr "type" spec then
103 if ! builtins.hasAttr "type" spec then
66 abort "ERROR: niv spec ${name} does not have a 'type' attribute"
104 abort "ERROR: niv spec ${name} does not have a 'type' attribute"
67− else if spec.type == "file" then fetch_file pkgs spec
105+ else if spec.type == "file" then fetch_file pkgs name spec
68 else if spec.type == "tarball" then fetch_tarball pkgs name spec
106 else if spec.type == "tarball" then fetch_tarball pkgs name spec
69− else if spec.type == "git" then fetch_git spec
107+ else if spec.type == "git" then fetch_git name spec
70 else if spec.type == "local" then fetch_local spec
108 else if spec.type == "local" then fetch_local spec
71 else if spec.type == "builtin-tarball" then fetch_builtin-tarball name
109 else if spec.type == "builtin-tarball" then fetch_builtin-tarball name
72 else if spec.type == "builtin-url" then fetch_builtin-url name
110 else if spec.type == "builtin-url" then fetch_builtin-url name
@@ -80,7 +118,10 @@ let
80 saneName = stringAsChars (c: if isNull (builtins.match "[a-zA-Z0-9]" c) then "_" else c) name;
118 saneName = stringAsChars (c: if isNull (builtins.match "[a-zA-Z0-9]" c) then "_" else c) name;
81 ersatz = builtins.getEnv "NIV_OVERRIDE_${saneName}";
119 ersatz = builtins.getEnv "NIV_OVERRIDE_${saneName}";
82 in
120 in
83− if ersatz == "" then drv else ersatz;
121+ if ersatz == "" then drv else
122+ # this turns the string into an actual Nix path (for both absolute and
123+ # relative paths)
124+ if builtins.substring 0 1 ersatz == "/" then /. + ersatz else /. + builtins.getEnv "PWD" + "/${ersatz}";
84
125
85 # Ports of functions for older nix versions
126 # Ports of functions for older nix versions
86
127
@@ -98,25 +139,29 @@ let
98
139
99 # https://github.com/NixOS/nixpkgs/blob/0258808f5744ca980b9a1f24fe0b1e6f0fecee9c/lib/strings.nix#L269
140 # https://github.com/NixOS/nixpkgs/blob/0258808f5744ca980b9a1f24fe0b1e6f0fecee9c/lib/strings.nix#L269
100 stringAsChars = f: s: concatStrings (map f (stringToCharacters s));
141 stringAsChars = f: s: concatStrings (map f (stringToCharacters s));
142+ concatMapStrings = f: list: concatStrings (map f list);
101 concatStrings = builtins.concatStringsSep "";
143 concatStrings = builtins.concatStringsSep "";
102
144
145+ # https://github.com/NixOS/nixpkgs/blob/8a9f58a375c401b96da862d969f66429def1d118/lib/attrsets.nix#L331
146+ optionalAttrs = cond: as: if cond then as else {};
147+
103 # fetchTarball version that is compatible between all the versions of Nix
148 # fetchTarball version that is compatible between all the versions of Nix
104− builtins_fetchTarball = { url, name, sha256 }@attrs:
149+ builtins_fetchTarball = { url, name ? null, sha256 }@attrs:
105 let
150 let
106 inherit (builtins) lessThan nixVersion fetchTarball;
151 inherit (builtins) lessThan nixVersion fetchTarball;
107 in
152 in
108 if lessThan nixVersion "1.12" then
153 if lessThan nixVersion "1.12" then
109− fetchTarball { inherit name url; }
154+ fetchTarball ({ inherit url; } // (optionalAttrs (!isNull name) { inherit name; }))
110 else
155 else
111 fetchTarball attrs;
156 fetchTarball attrs;
112
157
113 # fetchurl version that is compatible between all the versions of Nix
158 # fetchurl version that is compatible between all the versions of Nix
114− builtins_fetchurl = { url, sha256 }@attrs:
159+ builtins_fetchurl = { url, name ? null, sha256 }@attrs:
115 let
160 let
116 inherit (builtins) lessThan nixVersion fetchurl;
161 inherit (builtins) lessThan nixVersion fetchurl;
117 in
162 in
118 if lessThan nixVersion "1.12" then
163 if lessThan nixVersion "1.12" then
119− fetchurl { inherit url; }
164+ fetchurl ({ inherit url; } // (optionalAttrs (!isNull name) { inherit name; }))
120 else
165 else
121 fetchurl attrs;
166 fetchurl attrs;
122
167
@@ -135,7 +180,8 @@ let
135 mkConfig =
180 mkConfig =
136 { sourcesFile ? if builtins.pathExists ./sources.json then ./sources.json else null
181 { sourcesFile ? if builtins.pathExists ./sources.json then ./sources.json else null
137 , sources ? if isNull sourcesFile then {} else builtins.fromJSON (builtins.readFile sourcesFile)
182 , sources ? if isNull sourcesFile then {} else builtins.fromJSON (builtins.readFile sourcesFile)
183+ , system ? builtins.currentSystem
138− , pkgs ? mkPkgs sources
184+ , pkgs ? mkPkgs sources system
139 }: rec {
185 }: rec {
140 # The sources, i.e. the attribute set of spec name to spec
186 # The sources, i.e. the attribute set of spec name to spec
141 inherit sources;
187 inherit sources;
rel8.cabal+86−56
@@ -1,30 +1,36 @@
1cabal-version: 2.0
1cabal-version: 2.0
2name: rel8
2name: rel8
3−version: 0.1.0.0
3+version: 1.4.0.0
4synopsis: Hey! Hey! Can u rel8?
4synopsis: Hey! Hey! Can u rel8?
5license: BSD3
5license: BSD3
6license-file: LICENSE
6license-file: LICENSE
7author: Oliver Charles
7author: Oliver Charles
8maintainer: ollie@ocharles.org.uk
8maintainer: ollie@ocharles.org.uk
9+homepage: https://github.com/circuithub/rel8
10+bug-reports: https://github.com/circuithub/rel8/issues
9−build-type: Custom
11+build-type: Simple
12+extra-doc-files:
13+ README.md
14+ Changelog.md
10
15
11−custom-setup
16+source-repository head
12− setup-depends:
17+ type: git
13− base >= 4 && <5,
18+ location: https://github.com/circuithub/rel8
14− Cabal,
15− cabal-doctest >= 1 && <1.1
16
19
17library
20library
18 build-depends:
21 build-depends:
19 aeson
22 aeson
20− , base ^>=4.12 || ^>= 4.13 || ^>= 4.14
23+ , base ^>= 4.14 || ^>=4.15 || ^>=4.16
24+ , bifunctors
21 , bytestring
25 , bytestring
22 , case-insensitive
26 , case-insensitive
23− , casing
27+ , comonad
24 , contravariant
28 , contravariant
25− , hasql
29+ , hasql ^>= 1.4.5.1 || ^>= 1.5.0.0 || ^>= 1.6.0.0
26− , opaleye ^>= 0.7.1.0
30+ , opaleye ^>= 0.9.6.1
31+ , pretty
27 , profunctors
32 , profunctors
33+ , product-profunctors
28 , scientific
34 , scientific
29 , semialign
35 , semialign
30 , semigroupoids
36 , semigroupoids
@@ -35,34 +41,63 @@ library
35 default-language:
41 default-language:
36 Haskell2010
42 Haskell2010
37 ghc-options:
43 ghc-options:
44+ -Werror=missing-methods -Werror=incomplete-patterns -Werror=missing-fields
38 -Weverything -Wno-unsafe -Wno-safe -Wno-missing-safe-haskell-mode
45 -Weverything -Wno-unsafe -Wno-safe -Wno-missing-safe-haskell-mode
39 -Wno-missing-import-lists -Wno-prepositive-qualified-module
46 -Wno-missing-import-lists -Wno-prepositive-qualified-module
40 -Wno-monomorphism-restriction
47 -Wno-monomorphism-restriction
41− -Wno-missing-local-signatures
48+ -Wno-missing-local-signatures
49+ -Wno-missing-kind-signatures
42 hs-source-dirs:
50 hs-source-dirs:
43 src
51 src
44 exposed-modules:
52 exposed-modules:
45 Rel8
53 Rel8
54+ Rel8.Expr.Num
55+ Rel8.Expr.Text
56+ Rel8.Expr.Time
57+ Rel8.Tabulate
58+
46 other-modules:
59 other-modules:
47 Rel8.Aggregate
60 Rel8.Aggregate
48
61
62+ Rel8.Column
63+ Rel8.Column.ADT
64+ Rel8.Column.Either
65+ Rel8.Column.Lift
66+ Rel8.Column.List
67+ Rel8.Column.Maybe
68+ Rel8.Column.NonEmpty
69+ Rel8.Column.Null
70+ Rel8.Column.These
71+
49 Rel8.Expr
72 Rel8.Expr
50 Rel8.Expr.Aggregate
73 Rel8.Expr.Aggregate
51 Rel8.Expr.Array
74 Rel8.Expr.Array
52 Rel8.Expr.Bool
75 Rel8.Expr.Bool
76+ Rel8.Expr.Default
53 Rel8.Expr.Eq
77 Rel8.Expr.Eq
54 Rel8.Expr.Function
78 Rel8.Expr.Function
55 Rel8.Expr.Null
79 Rel8.Expr.Null
56− Rel8.Expr.Num
57 Rel8.Expr.Opaleye
80 Rel8.Expr.Opaleye
58 Rel8.Expr.Ord
81 Rel8.Expr.Ord
59 Rel8.Expr.Order
82 Rel8.Expr.Order
83+ Rel8.Expr.Sequence
60 Rel8.Expr.Serialize
84 Rel8.Expr.Serialize
61− Rel8.Expr.Text
85+ Rel8.Expr.Window
62− Rel8.Expr.Time
63
86
64− Rel8.Kind.Labels
87+ Rel8.FCF
88+
89+ Rel8.Kind.Algebra
65− Rel8.Kind.Necessity
90+ Rel8.Kind.Context
91+
92+ Rel8.Generic.Construction
93+ Rel8.Generic.Construction.ADT
94+ Rel8.Generic.Construction.Record
95+ Rel8.Generic.Map
96+ Rel8.Generic.Record
97+ Rel8.Generic.Rel8able
98+ Rel8.Generic.Table
99+ Rel8.Generic.Table.ADT
100+ Rel8.Generic.Table.Record
66
101
67 Rel8.Order
102 Rel8.Order
68
103
@@ -71,84 +106,88 @@ library
71 Rel8.Query.Distinct
106 Rel8.Query.Distinct
72 Rel8.Query.Each
107 Rel8.Query.Each
73 Rel8.Query.Either
108 Rel8.Query.Either
109+ Rel8.Query.Evaluate
74 Rel8.Query.Exists
110 Rel8.Query.Exists
75 Rel8.Query.Filter
111 Rel8.Query.Filter
112+ Rel8.Query.Indexed
76 Rel8.Query.Limit
113 Rel8.Query.Limit
77 Rel8.Query.List
114 Rel8.Query.List
78 Rel8.Query.Maybe
115 Rel8.Query.Maybe
79 Rel8.Query.Null
116 Rel8.Query.Null
80 Rel8.Query.Opaleye
117 Rel8.Query.Opaleye
81− Rel8.Query.Optimize
82 Rel8.Query.Order
118 Rel8.Query.Order
119+ Rel8.Query.Rebind
83 Rel8.Query.Set
120 Rel8.Query.Set
84 Rel8.Query.SQL
121 Rel8.Query.SQL
85 Rel8.Query.These
122 Rel8.Query.These
86 Rel8.Query.Values
123 Rel8.Query.Values
124+ Rel8.Query.Window
87
125
88− Rel8.Schema.Column
89− Rel8.Schema.Context
90− Rel8.Schema.Context.Identity
91− Rel8.Schema.Context.Label
92 Rel8.Schema.Context.Nullify
126 Rel8.Schema.Context.Nullify
93 Rel8.Schema.Dict
127 Rel8.Schema.Dict
94 Rel8.Schema.Field
128 Rel8.Schema.Field
95− Rel8.Schema.Generic
96− Rel8.Schema.Generic.Test
97 Rel8.Schema.HTable
129 Rel8.Schema.HTable
98 Rel8.Schema.HTable.Either
130 Rel8.Schema.HTable.Either
99 Rel8.Schema.HTable.Identity
131 Rel8.Schema.HTable.Identity
100 Rel8.Schema.HTable.Label
132 Rel8.Schema.HTable.Label
101 Rel8.Schema.HTable.List
133 Rel8.Schema.HTable.List
134+ Rel8.Schema.HTable.MapTable
102 Rel8.Schema.HTable.Maybe
135 Rel8.Schema.HTable.Maybe
103 Rel8.Schema.HTable.NonEmpty
136 Rel8.Schema.HTable.NonEmpty
104 Rel8.Schema.HTable.Nullify
137 Rel8.Schema.HTable.Nullify
105− Rel8.Schema.HTable.Pair
138+ Rel8.Schema.HTable.Product
106− Rel8.Schema.HTable.Quartet
107− Rel8.Schema.HTable.Quintet
108 Rel8.Schema.HTable.These
139 Rel8.Schema.HTable.These
109− Rel8.Schema.HTable.Trio
110− Rel8.Schema.HTable.Type
111 Rel8.Schema.HTable.Vectorize
140 Rel8.Schema.HTable.Vectorize
112 Rel8.Schema.Kind
141 Rel8.Schema.Kind
113− Rel8.Schema.Nullability
142+ Rel8.Schema.Name
143+ Rel8.Schema.Null
144+ Rel8.Schema.Result
114 Rel8.Schema.Spec
145 Rel8.Schema.Spec
115− Rel8.Schema.Spec.ConstrainDBType
116− Rel8.Schema.Spec.ConstrainType
117 Rel8.Schema.Table
146 Rel8.Schema.Table
118
147
119 Rel8.Statement.Delete
148 Rel8.Statement.Delete
120 Rel8.Statement.Insert
149 Rel8.Statement.Insert
150+ Rel8.Statement.OnConflict
121 Rel8.Statement.Returning
151 Rel8.Statement.Returning
122 Rel8.Statement.Select
152 Rel8.Statement.Select
153+ Rel8.Statement.Set
154+ Rel8.Statement.SQL
123 Rel8.Statement.Update
155 Rel8.Statement.Update
156+ Rel8.Statement.Using
124 Rel8.Statement.View
157 Rel8.Statement.View
158+ Rel8.Statement.Where
125
159
126 Rel8.Table
160 Rel8.Table
161+ Rel8.Table.ADT
127 Rel8.Table.Aggregate
162 Rel8.Table.Aggregate
128 Rel8.Table.Alternative
163 Rel8.Table.Alternative
129 Rel8.Table.Bool
164 Rel8.Table.Bool
165+ Rel8.Table.Cols
130 Rel8.Table.Either
166 Rel8.Table.Either
131 Rel8.Table.Eq
167 Rel8.Table.Eq
132− Rel8.Table.Insert
168+ Rel8.Table.HKD
133− Rel8.Table.Lifted
134 Rel8.Table.List
169 Rel8.Table.List
135 Rel8.Table.Maybe
170 Rel8.Table.Maybe
136 Rel8.Table.Name
171 Rel8.Table.Name
137 Rel8.Table.NonEmpty
172 Rel8.Table.NonEmpty
173+ Rel8.Table.Null
174+ Rel8.Table.Nullify
138 Rel8.Table.Opaleye
175 Rel8.Table.Opaleye
139 Rel8.Table.Ord
176 Rel8.Table.Ord
140 Rel8.Table.Order
177 Rel8.Table.Order
141− Rel8.Table.Recontextualize
178+ Rel8.Table.Projection
179+ Rel8.Table.Rel8able
142 Rel8.Table.Serialize
180 Rel8.Table.Serialize
143 Rel8.Table.These
181 Rel8.Table.These
182+ Rel8.Table.Transpose
144 Rel8.Table.Undefined
183 Rel8.Table.Undefined
145−
184+ Rel8.Table.Window
146− Rel8.Tabulate
147
185
148 Rel8.Type
186 Rel8.Type
149 Rel8.Type.Array
187 Rel8.Type.Array
150− Rel8.Type.Array1D
188+ Rel8.Type.Composite
151 Rel8.Type.Eq
189 Rel8.Type.Eq
190+ Rel8.Type.Enum
152 Rel8.Type.Information
191 Rel8.Type.Information
153 Rel8.Type.JSONEncoded
192 Rel8.Type.JSONEncoded
154 Rel8.Type.JSONBEncoded
193 Rel8.Type.JSONBEncoded
@@ -161,8 +200,8 @@ library
161 Rel8.Type.Sum
200 Rel8.Type.Sum
162 Rel8.Type.Tag
201 Rel8.Type.Tag
163
202
164− Rel8.Opaque
203+ Rel8.Window
165− Rel8.Schema.Structure
204+
166
205
167test-suite tests
206test-suite tests
168 type: exitcode-stdio-1.0
207 type: exitcode-stdio-1.0
@@ -172,9 +211,9 @@ test-suite tests
172 , case-insensitive
211 , case-insensitive
173 , containers
212 , containers
174 , hasql
213 , hasql
214+ , hasql-transaction
175− , hedgehog ^>=1.0.2
215+ , hedgehog ^>= 1.0 || ^>= 1.1
176− , lifted-base ^>=0.2.3.12
216+ , mmorph
177− , monad-control ^>=1.0.2.3
178 , rel8
217 , rel8
179 , scientific
218 , scientific
180 , tasty
219 , tasty
@@ -182,8 +221,12 @@ test-suite tests
182 , text
221 , text
183 , time
222 , time
184 , tmp-postgres ^>=1.34.1.0
223 , tmp-postgres ^>=1.34.1.0
224+ , transformers
185 , uuid
225 , uuid
186
226
227+ other-modules:
228+ Rel8.Generic.Rel8able.Test
229+
187 main-is: Main.hs
230 main-is: Main.hs
188 hs-source-dirs: tests
231 hs-source-dirs: tests
189 default-language: Haskell2010
232 default-language: Haskell2010
@@ -192,16 +235,3 @@ test-suite tests
192 -Wno-missing-import-lists -Wno-prepositive-qualified-module
235 -Wno-missing-import-lists -Wno-prepositive-qualified-module
193 -Wno-deprecations -Wno-monomorphism-restriction
236 -Wno-deprecations -Wno-monomorphism-restriction
194 -Wno-missing-local-signatures -Wno-implicit-prelude
237 -Wno-missing-local-signatures -Wno-implicit-prelude
195−
196−test-suite doctests
197− type: exitcode-stdio-1.0
198− build-depends:
199− base
200− , base-compat
201− , bytestring
202− , doctest
203− , hasql
204− , tmp-postgres
205−
206− main-is: Doctest.hs
207− default-language: Haskell2010
shell.nix+4−4
@@ -1,11 +1,11 @@
1let
1let
2 sources = import ./nix/sources.nix;
2 sources = import ./nix/sources.nix;
3− pkgs = import sources.nixpkgs {};
3+ pkgs = import sources.nixpkgs {overlays = [];};
4 hsPkgs = import ./default.nix;
4 hsPkgs = import ./default.nix;
5in
5in
6 hsPkgs.shellFor {
6 hsPkgs.shellFor {
7− withHoogle = true;
7+ withHoogle = false;
8− tools = { cabal = "3.2.0.0"; haskell-language-server = "latest"; };
8+ tools = { cabal = "latest"; };
9 exactDeps = false;
9 exactDeps = false;
10− buildInputs = [ pkgs.postgresql ];
10+ buildInputs = [ pkgs.postgresql pkgs.pythonPackages.sphinx ];
11 }
11 }
src/Rel8.hs+391−397
@@ -1,19 +1,7 @@
1{-# language DuplicateRecordFields #-}
1{-# language DuplicateRecordFields #-}
2
2
3module Rel8
3module Rel8
4− ( -- * Getting Started
5− -- $setup
6−
7− -- ** Writing Queries
8− -- $guideQueries
9−
10− -- ** Joins
11− -- $guideJoins
12−
13− -- ** Aggregation
14− -- $guideAggregation
15−
16− -- * Database types
4+ ( -- * Database types
17 -- ** @DBType@
5 -- ** @DBType@
18 DBType(..)
6 DBType(..)
19
7
@@ -25,6 +13,10 @@ module Rel8
25 -- **** @ReadShow@
13 -- **** @ReadShow@
26 , ReadShow(..)
14 , ReadShow(..)
27
15
16+ -- **** Generic
17+ , Composite(..), DBComposite(..), compose, decompose
18+ , Enum(..), DBEnum(..), Enumable
19+
28 -- *** @TypeInformation@
20 -- *** @TypeInformation@
29 , TypeInformation(..)
21 , TypeInformation(..)
30 , mapTypeInformation
22 , mapTypeInformation
@@ -34,32 +26,44 @@ module Rel8
34 , DBSemigroup(..)
26 , DBSemigroup(..)
35 , DBMonoid(..)
27 , DBMonoid(..)
36 , DBNum
28 , DBNum
29+ , DBIntegral
37 , DBFractional
30 , DBFractional
31+ , DBFloating
38
32
39 -- * Tables and higher-kinded tables
33 -- * Tables and higher-kinded tables
40− , Rel8able
34+ , Rel8able, KRel8able
41 , Column
35 , Column
36+ , HADT
37+ , HEither
42 , HMaybe
38 , HMaybe
43 , HList
39 , HList
44 , HNonEmpty
40 , HNonEmpty
41+ , HNull
45 , HThese
42 , HThese
43+ , Lift
46
44
47− , Table
45+ , Table(..)
46+ , HTable
47+ , Transposes
48 , AltTable((<|>:))
48 , AltTable((<|>:))
49+ , AlternativeTable( emptyTable )
49− , EqTable, (==:), (/=:)
50+ , EqTable(..), (==:), (/=:)
50− , OrdTable, ascTable, descTable
51+ , OrdTable(..), (<:), (<=:), (>:), (>=:), ascTable, descTable, greatest, least
51 , lit
52 , lit
52 , bool
53 , bool
53 , case_
54 , case_
55+ , castTable
54
56
55 -- ** @MaybeTable@
57 -- ** @MaybeTable@
56 , MaybeTable
58 , MaybeTable
57− , maybeTable, nothingTable, justTable
59+ , maybeTable, ($?), nothingTable, justTable
58 , isNothingTable, isJustTable
60 , isNothingTable, isJustTable
61+ , fromMaybeTable
59 , optional
62 , optional
60 , catMaybeTable
63 , catMaybeTable
61− , bindMaybeTable
62 , traverseMaybeTable
64 , traverseMaybeTable
65+ , aggregateMaybeTable
66+ , nameMaybeTable
63
67
64 -- ** @EitherTable@
68 -- ** @EitherTable@
65 , EitherTable
69 , EitherTable
@@ -67,8 +71,9 @@ module Rel8
67 , isLeftTable, isRightTable
71 , isLeftTable, isRightTable
68 , keepLeftTable
72 , keepLeftTable
69 , keepRightTable
73 , keepRightTable
70− , bindEitherTable
71 , bitraverseEitherTable
74 , bitraverseEitherTable
75+ , aggregateEitherTable
76+ , nameEitherTable
72
77
73 -- ** @TheseTable@
78 -- ** @TheseTable@
74 , TheseTable
79 , TheseTable
@@ -76,39 +81,100 @@ module Rel8
76 , isThisTable, isThatTable, isThoseTable
81 , isThisTable, isThatTable, isThoseTable
77 , hasHereTable, hasThereTable
82 , hasHereTable, hasThereTable
78 , justHereTable, justThereTable
83 , justHereTable, justThereTable
84+ , alignMaybeTable
79 , alignBy
85 , alignBy
80 , keepHereTable, loseHereTable
86 , keepHereTable, loseHereTable
81 , keepThereTable, loseThereTable
87 , keepThereTable, loseThereTable
82 , keepThisTable, loseThisTable
88 , keepThisTable, loseThisTable
83 , keepThatTable, loseThatTable
89 , keepThatTable, loseThatTable
84 , keepThoseTable, loseThoseTable
90 , keepThoseTable, loseThoseTable
85− , bindTheseTable
86 , bitraverseTheseTable
91 , bitraverseTheseTable
92+ , aggregateTheseTable
93+ , nameTheseTable
87
94
88 -- ** @ListTable@
95 -- ** @ListTable@
89 , ListTable
96 , ListTable
97+ , listTable, ($*)
98+ , nameListTable
90 , many
99 , many
100+ , manyExpr
101+ , catListTable
102+ , catList
91
103
92 -- ** @NonEmptyTable@
104 -- ** @NonEmptyTable@
93 , NonEmptyTable
105 , NonEmptyTable
106+ , nonEmptyTable, ($+)
107+ , nameNonEmptyTable
94 , some
108 , some
109+ , someExpr
110+ , catNonEmptyTable
111+ , catNonEmpty
112+
113+ -- ** @NullTable@
114+ , NullTable
115+ , nullableTable, nullTable, nullifyTable
116+ , isNullTable, isNonNullTable
117+ , catNullTable
118+ , nameNullTable
119+ , toNullTable, toMaybeTable
120+
121+ -- ** Algebraic data types / sum types
122+ -- $adts
123+
124+ -- *** Naming of ADTs
125+ -- $naming
126+ , NameADT, nameADT
127+ , ADT, ADTable
128+
129+ -- *** Deconstruction of ADTs
130+ -- $deconstruction
131+ , DeconstructADT, deconstructADT
132+
133+ -- *** Construction of ADTs
134+ -- $construction
135+ , BuildADT, buildADT
136+ , ConstructADT, constructADT
137+
138+ -- *** Other ADT operations
139+ , AggregateADT, aggregateADT
140+
141+ -- *** Miscellaneous notes
142+ -- $misc-notes
143+
144+ -- ** @HKD@
145+ , HKD, HKDable
146+ , BuildHKD, buildHKD
147+ , ConstructHKD, constructHKD
148+ , DeconstructHKD, deconstructHKD
149+ , NameHKD, nameHKD
150+ , AggregateHKD, aggregateHKD
95
151
96 -- ** Table schemas
152 -- ** Table schemas
97 , TableSchema(..)
153 , TableSchema(..)
98 , Name
154 , Name
155+ , namesFromLabels
156+ , namesFromLabelsWith
99
157
100 -- * Expressions
158 -- * Expressions
101 , Expr
159 , Expr
102 , Sql
160 , Sql
103 , litExpr
161 , litExpr
162+ , unsafeCastExpr
163+ , unsafeLiteral
104
164
105 -- ** @null@
165 -- ** @null@
166+ , NotNull
167+ , Nullable
168+ , Homonullable
169+ , null
106 , nullify
170 , nullify
107 , nullable
171 , nullable
108 , isNull
172 , isNull
109 , isNonNull
173 , isNonNull
110− , mapNullable
174+ , mapNull
111− , catNullable
175+ , liftOpNull
176+ , catNull
177+ , coalesce
112
178
113 -- ** Boolean operations
179 -- ** Boolean operations
114 , DBEq
180 , DBEq
@@ -118,6 +184,7 @@ module Rel8
118 , (==.), (/=.), (==?), (/=?)
184 , (==.), (/=.), (==?), (/=?)
119 , in_
185 , in_
120 , boolExpr, caseExpr
186 , boolExpr, caseExpr
187+ , like, ilike
121
188
122 -- ** Ordering
189 -- ** Ordering
123 , DBOrd
190 , DBOrd
@@ -129,11 +196,19 @@ module Rel8
129 , Function
196 , Function
130 , function
197 , function
131 , nullaryFunction
198 , nullaryFunction
199+ , binaryOperator
132
200
133 -- * Queries
201 -- * Queries
134 , Query
202 , Query
135 , showQuery
203 , showQuery
136
204
205+ -- ** Projection
206+ , Projection
207+ , Projectable( project )
208+ , Biprojectable( biproject )
209+ , Projecting
210+ , Field
211+
137 -- ** Selecting rows
212 -- ** Selecting rows
138 , Selects
213 , Selects
139 , each
214 , each
@@ -142,8 +217,8 @@ module Rel8
142 -- ** Filtering
217 -- ** Filtering
143 , filter
218 , filter
144 , where_
219 , where_
145− , whereExists
220+ , present
146− , whereNotExists
221+ , absent
147 , distinct
222 , distinct
148 , distinctOn
223 , distinctOn
149 , distinctOnBy
224 , distinctOnBy
@@ -173,13 +248,16 @@ module Rel8
173
248
174 -- ** Aggregation
249 -- ** Aggregation
175 , Aggregate
250 , Aggregate
251+ , Aggregates
176 , aggregate
252 , aggregate
177− , listAgg
253+ , countRows
178− , nonEmptyAgg
179 , groupBy
254 , groupBy
255+ , listAgg, listAggExpr
256+ , mode
257+ , nonEmptyAgg, nonEmptyAggExpr
180 , DBMax, max
258 , DBMax, max
181 , DBMin, min
259 , DBMin, min
182− , DBSum, sum
260+ , DBSum, sum, sumWhere, avg
183 , DBString, stringAgg
261 , DBString, stringAgg
184 , count
262 , count
185 , countStar
263 , countStar
@@ -196,40 +274,71 @@ module Rel8
196 , nullsFirst
274 , nullsFirst
197 , nullsLast
275 , nullsLast
198
276
277+ -- ** Window functions
278+ , Window
279+ , window
280+ , Partition
281+ , over
282+ , partitionBy
283+ , orderPartitionBy
284+ , cumulative
285+ , cumulative_
286+ , currentRow
287+ , rowNumber
288+ , rank
289+ , denseRank
290+ , percentRank
291+ , cumeDist
292+ , ntile
293+ , lag
294+ , lead
295+ , firstValue
296+ , lastValue
297+ , nthValue
298+ , indexed
299+
300+ -- ** Bindings
301+ , rebind
302+
199 -- * IO
303 -- * IO
200 , Serializable
304 , Serializable
305+ , ToExprs
306+ , Result
201
307
202 -- * Running statements
308 -- * Running statements
309+ -- $running
310+
203 -- ** @SELECT@
311 -- ** @SELECT@
204 , select
312 , select
205
313
206 -- ** @INSERT@
314 -- ** @INSERT@
207 , Insert(..)
315 , Insert(..)
208 , OnConflict(..)
316 , OnConflict(..)
317+ , Upsert(..)
209 , insert
318 , insert
210− , toInsert
319+ , unsafeDefault
211− , toInsertDefaults
320+ , showInsert
212
321
213 -- ** @DELETE@
322 -- ** @DELETE@
214 , Delete(..)
323 , Delete(..)
215 , delete
324 , delete
325+ , showDelete
216
326
217 -- ** @UPDATE@
327 -- ** @UPDATE@
218− , update
219 , Update(..)
328 , Update(..)
329+ , update
330+ , showUpdate
220
331
221 -- ** @.. RETURNING@
332 -- ** @.. RETURNING@
222 , Returning(..)
333 , Returning(..)
223
334
224− -- * TODO
335+ -- ** @CREATE VIEW@
225− -- TODO
336+ , createView
226− -- These need organizing, but are reachable from Rel8's documentation so we
337+ , createOrReplaceView
227− -- do need to export and document them.
338+
228− , Nullabilizes
339+ -- ** Sequences
229− , HTable
340+ , nextval
230− , Labelable
341+ , evaluate
231− , Context
232− , IsMaybe
233 ) where
342 ) where
234
343
235-- base
344-- base
@@ -237,64 +346,94 @@ import Prelude ()
237
346
238-- rel8
347-- rel8
239import Rel8.Aggregate
348import Rel8.Aggregate
349+import Rel8.Column
350+import Rel8.Column.ADT
351+import Rel8.Column.Either
352+import Rel8.Column.Lift
353+import Rel8.Column.List
354+import Rel8.Column.Maybe
355+import Rel8.Column.NonEmpty
356+import Rel8.Column.Null
357+import Rel8.Column.These
240import Rel8.Expr
358import Rel8.Expr
241import Rel8.Expr.Aggregate
359import Rel8.Expr.Aggregate
242import Rel8.Expr.Bool
360import Rel8.Expr.Bool
361+import Rel8.Expr.Default
243import Rel8.Expr.Eq
362import Rel8.Expr.Eq
244import Rel8.Expr.Function
363import Rel8.Expr.Function
245import Rel8.Expr.Null
364import Rel8.Expr.Null
365+import Rel8.Expr.Opaleye (unsafeCastExpr, unsafeLiteral)
246import Rel8.Expr.Ord
366import Rel8.Expr.Ord
247import Rel8.Expr.Order
367import Rel8.Expr.Order
248import Rel8.Expr.Serialize
368import Rel8.Expr.Serialize
369+import Rel8.Expr.Sequence
370+import Rel8.Expr.Text ( like, ilike )
371+import Rel8.Expr.Window hiding ( cumulative )
372+import Rel8.Generic.Rel8able ( KRel8able, Rel8able )
249import Rel8.Order
373import Rel8.Order
250import Rel8.Query
374import Rel8.Query
251import Rel8.Query.Aggregate
375import Rel8.Query.Aggregate
252import Rel8.Query.Distinct
376import Rel8.Query.Distinct
253import Rel8.Query.Each
377import Rel8.Query.Each
254import Rel8.Query.Either
378import Rel8.Query.Either
379+import Rel8.Query.Evaluate
255import Rel8.Query.Exists
380import Rel8.Query.Exists
256import Rel8.Query.Filter
381import Rel8.Query.Filter
382+import Rel8.Query.Indexed
257import Rel8.Query.Limit
383import Rel8.Query.Limit
258import Rel8.Query.List
384import Rel8.Query.List
259import Rel8.Query.Maybe
385import Rel8.Query.Maybe
260import Rel8.Query.Null
386import Rel8.Query.Null
261import Rel8.Query.Order
387import Rel8.Query.Order
388+import Rel8.Query.Rebind
262import Rel8.Query.SQL (showQuery)
389import Rel8.Query.SQL (showQuery)
263import Rel8.Query.Set
390import Rel8.Query.Set
264import Rel8.Query.These
391import Rel8.Query.These
265import Rel8.Query.Values
392import Rel8.Query.Values
266−import Rel8.Schema.Column
393+import Rel8.Query.Window
267−import Rel8.Schema.Context (Name)
394+import Rel8.Schema.Field
268−import Rel8.Schema.Context.Label
269−import Rel8.Schema.Generic
270import Rel8.Schema.HTable
395import Rel8.Schema.HTable
271−import Rel8.Schema.Nullability
396+import Rel8.Schema.Name
397+import Rel8.Schema.Null hiding ( nullable )
398+import Rel8.Schema.Result ( Result )
272import Rel8.Schema.Table
399import Rel8.Schema.Table
273import Rel8.Statement.Delete
400import Rel8.Statement.Delete
274import Rel8.Statement.Insert
401import Rel8.Statement.Insert
402+import Rel8.Statement.OnConflict
275import Rel8.Statement.Returning
403import Rel8.Statement.Returning
276import Rel8.Statement.Select
404import Rel8.Statement.Select
405+import Rel8.Statement.SQL
277import Rel8.Statement.Update
406import Rel8.Statement.Update
407+import Rel8.Statement.View
278import Rel8.Table
408import Rel8.Table
409+import Rel8.Table.ADT
279import Rel8.Table.Aggregate
410import Rel8.Table.Aggregate
280import Rel8.Table.Alternative
411import Rel8.Table.Alternative
281import Rel8.Table.Bool
412import Rel8.Table.Bool
282import Rel8.Table.Either
413import Rel8.Table.Either
283import Rel8.Table.Eq
414import Rel8.Table.Eq
284−import Rel8.Table.Insert
415+import Rel8.Table.HKD
285import Rel8.Table.List
416import Rel8.Table.List
286import Rel8.Table.Maybe
417import Rel8.Table.Maybe
418+import Rel8.Table.Name
287import Rel8.Table.NonEmpty
419import Rel8.Table.NonEmpty
420+import Rel8.Table.Null
421+import Rel8.Table.Opaleye ( castTable )
288import Rel8.Table.Ord
422import Rel8.Table.Ord
289import Rel8.Table.Order
423import Rel8.Table.Order
290−import Rel8.Table.Recontextualize
424+import Rel8.Table.Projection
425+import Rel8.Table.Rel8able ()
291import Rel8.Table.Serialize
426import Rel8.Table.Serialize
292import Rel8.Table.These
427import Rel8.Table.These
428+import Rel8.Table.Transpose
429+import Rel8.Table.Window
293import Rel8.Type
430import Rel8.Type
431+import Rel8.Type.Composite
294import Rel8.Type.Eq
432import Rel8.Type.Eq
433+import Rel8.Type.Enum
295import Rel8.Type.Information
434import Rel8.Type.Information
296−import Rel8.Type.JSONEncoded
297import Rel8.Type.JSONBEncoded
435import Rel8.Type.JSONBEncoded
436+import Rel8.Type.JSONEncoded
298import Rel8.Type.Monoid
437import Rel8.Type.Monoid
299import Rel8.Type.Num
438import Rel8.Type.Num
300import Rel8.Type.Ord
439import Rel8.Type.Ord
@@ -302,361 +441,216 @@ import Rel8.Type.ReadShow
302import Rel8.Type.Semigroup
441import Rel8.Type.Semigroup
303import Rel8.Type.String
442import Rel8.Type.String
304import Rel8.Type.Sum
443import Rel8.Type.Sum
444+import Rel8.Window
305
445
306
446
307−-- $setup
447+-- $running
308−--
448+-- To run queries and otherwise interact with a PostgreSQL database, Rel8
309−-- In this section, we'll take a look at using Rel8 to work with a small
449+-- provides 'select', 'insert', 'update' and 'delete' functions. Note that
310−-- database for Haskell packages. We'll take a look at idiomatic usage of Rel8,
450+-- 'insert', 'update' and 'delete' will generally need the
311−-- mapping tables to Haskell, and then look at writing some simple queries.
451+-- `DuplicateRecordFields` language extension enabled.
312−--
313−-- The documentation in this library uses the following language extensions:
314−--
315−-- >>> :set -XBlockArguments
316−-- >>> :set -XDeriveAnyClass
317−-- >>> :set -XDeriveGeneric
318−-- >>> :set -XDerivingStrategies
319−-- >>> :set -XDerivingVia
320−-- >>> :set -XDuplicateRecordFields
321−-- >>> :set -XGeneralizedNewtypeDeriving
322−-- >>> :set -XOverloadedStrings
323−-- >>> :set -XStandaloneDeriving
324−-- >>> :set -XTypeApplications
325−-- >>> :set -XTypeFamilies
326−--
327−-- Before we start writing any Haskell, let's take a look at the schema we'll
328−-- work with.
329−--
330−-- > author: project:
331−-- >
332−-- > Column │ Type │ Nullable Column │ Type │ Nullable
333−-- > ═══════════╪═════════╪══════════ ═══════════╪═════════╪══════════
334−-- > author_id │ integer │ not null author_id │ integer │ not null
335−-- > name │ text │ not null name │ text │ not null
336−-- > url │ text │
337−--
338−-- Our schema consists of two tables - @author@ and @project@. A @project@
339−-- always has an @author@, but not all @author@s have projects. Each @author@
340−-- has a name and (maybe) an associated website, and each project has a name.
341−--
342−-- Now that we've seen our schema, we can begin writing a mapping in Rel8. The
343−-- idiomatic way to map a table is to use a record that is parameterised what
344−-- Rel8 calls an /interpretation functor/, and to define each field with
345−-- 'Column'. For this type to be usable with Rel8 we need it to be an instance
346−-- of 'HigherKindedTable', which can be derived with a combination of
347−-- @DeriveAnyClass@ and @DeriveGeneric@.
348−--
349−-- Following these steps for @author@, we have:
350−--
351−-- > data Author f = Author
352−-- > { authorId :: Column f Int64
353−-- > , name :: Column f Text
354−-- > , url :: Column f (Maybe Text)
355−-- > } deriving (Generic, HigherKindedTable)
356−--
357−-- This is a perfectly reasonable definition, but cautious readers might notice
358−-- a problem - in particular, with the type of the @authorId@ field. While
359−-- @Int64@ is correct, it's not the best type. If we had other identifier types
360−-- in our project, it would be too easy to accidentally mix them up and create
361−-- nonsensical joins. As Haskell programmers, we often solve this problem by
362−-- creating @newtype@ wrappers, and we can also use this technique with Rel8:
363−--
364−-- >>> :{
365−-- newtype AuthorId = AuthorId { toInt64 :: Int64 }
366−-- deriving newtype (DBEq, DBType, Eq, Show)
367−-- :}
368−--
369−-- Now we can write our final schema mapping. First, the @author@ table:
370−--
371−-- >>> :{
372−-- data Author f = Author
373−-- { authorId :: Column f AuthorId
374−-- , authorName :: Column f Text
375−-- , authorUrl :: Column f (Maybe Text)
376−-- }
377−-- deriving stock Generic
378−-- deriving anyclass HigherKindedTable
379−-- :}
380−--
381−-- And similarly, the @project@ table:
382−--
383−-- >>> :{
384−-- data Project f = Project
385−-- { projectAuthorId :: Column f AuthorId
386−-- , projectName :: Column f Text
387−-- }
388−-- deriving stock Generic
389−-- deriving anyclass HigherKindedTable
390−-- :}
391−--
392−-- To show query results in this documentation, we'll also need @Show@
393−-- instances: Unfortunately these definitions look a bit scary, but they are
394−-- essentially just @deriving (Show)@:
395−--
396−-- >>> deriving stock instance f ~ Identity => Show (Author f)
397−-- >>> deriving stock instance f ~ Identity => Show (Project f)
398−--
399−-- These data types describe the structural mapping of the tables, but we also
400−-- need to specify a 'TableSchema' for each table. A @TableSchema@ contains the
401−-- name of the table and the name of all columns in the table, which will
402−-- ultimately allow us to @SELECT@ and @INSERT@ rows for these tables.
403−--
404−-- To define a @TableSchema@, we just need to fill construct appropriate
405−-- @TableSchema@ values. When it comes to the @tableColumns@ field, we
406−-- construct values of our data types above, and set each field to the name of
407−-- the column that it maps to:
408−--
409−-- First, @authorSchema@ describes the column names of the @author@ table when
410−-- associated with the @Author@ type:
411−--
412−-- >>> :{
413−-- authorSchema :: TableSchema (Author ColumnSchema)
414−-- authorSchema = TableSchema
415−-- { tableName = "author"
416−-- , tableSchema = Nothing
417−-- , tableColumns = Author
418−-- { authorId = "author_id"
419−-- , authorName = "name"
420−-- , authorUrl = "url"
421−-- }
422−-- }
423−-- :}
424−--
425−-- And likewise for @project@ and @Project@:
426−--
427−-- >>> :{
428−-- projectSchema :: TableSchema (Project ColumnSchema)
429−-- projectSchema = TableSchema
430−-- { tableName = "project"
431−-- , tableSchema = Nothing
432−-- , tableColumns = Project
433−-- { projectAuthorId = "author_id"
434−-- , projectName = "name"
435−-- }
436−-- }
437−-- :}
438−--
439−-- Aside: you might be wondering why this information isn't in the definitions
440−-- of @Author@ and @Project@ above. Rel8 decouples @TableSchema@ from the data
441−-- types themselves, as not all tables you define will necessarily have a
442−-- schema. For example, Rel8 allows you to define helper types to simplify the
443−-- types of queries - these tables only exist at query time, but there is no
444−-- corresponding base table. We'll see more on this idea later!
445−--
446−-- With these table definitions, we can now start writing some queries! To
447−-- actually run a query, we'll need a database connection. Rel8 uses the
448−-- @hasql@ library, and for this documentation we'll get the connection string
449−-- from the @$TEST_DATABASE_URL@ environment variable.
450−--
451−-- >>> connectionString <- System.Environment.getEnv "TEST_DATABASE_URL"
452−-- >>> Right c <- Hasql.Connection.acquire (Data.ByteString.Char8.pack connectionString)
453−-- >>> Control.Monad.void $ Hasql.Session.run (Hasql.Session.sql "BEGIN") c
454−
455−-- $guideQueries
456−--
457−-- First, we'll take a look at @SELECT@ statements - usually the bulk of most
458−-- database heavy applications.
459−--
460−-- In Rel8, @SELECT@ statements are built using the 'Query' monad. You can
461−-- think of this monad like the ordinary @[]@ (List) monad - but this isn't
462−-- required knowledge.
463−--
464−-- To start, we'll look at one of the simplest queries possible - a basic
465−-- @SELECT * FROM@ statement. To select all rows from a table, we use 'each',
466−-- and supply a 'TableSchema'. So to select all @project@ rows, we can write:
467−--
468−-- >>> :t each projectSchema
469−-- each projectSchema :: Query (Project Expr)
470−--
471−-- Notice that @each@ gives us a @Query@ that yields @Project Expr@ rows. To
472−-- see what this means, let's have a look at a single field of a
473−-- @Project Expr@:
474−--
475−-- >>> let aProjectExpr = undefined :: Project Expr
476−-- >>> :t projectAuthorId aProjectExpr
477−-- projectAuthorId aProjectExpr :: Expr AuthorId
478−--
479−-- Recall we defined @projectAuthorId@ as @Column f AuthorId@. Now we have @f@
480−-- is @Expr@, and @Column Expr AuthorId@ reduces to @Expr AuthorId@. We'll see
481−-- more about @Expr@ soon, but you can think of @Expr a@ as "SQL expressions of
482−-- type @a@".
483−--
484−-- To execute this @Query@, we pass it to 'select':
485−--
486−-- >>> :t select c (each projectSchema)
487−-- select c (each projectSchema) :: MonadIO m => m [Project Identity]
488−--
489−-- When we @select@ things containing @Expr@s, Rel8 builds a new response table
490−-- with the @Identity@ interpretation. This means you'll get back plain Haskell
491−-- values. Studying @projectAuthorId@ again, we have:
492−--
493−-- >>> let aProjectIdentity = undefined :: Project Identity
494−-- >>> :t projectAuthorId aProjectIdentity
495−-- projectAuthorId aProjectIdentity :: AuthorId
496−--
497−-- Here @Column Identity AuthorId@ reduces to just @AuthorId@, with no
498−-- wrappping type at all.
499−--
500−-- Putting this all together, we can run our first query:
501−--
502−-- >>> select c (each projectSchema) >>= mapM_ print
503−-- Project {projectAuthorId = 1, projectName = "rel8"}
504−-- Project {projectAuthorId = 2, projectName = "aeson"}
505−-- Project {projectAuthorId = 2, projectName = "text"}
506−--
507−-- Cool!
508−--
509−-- We now know that 'each' is the equivalent of a @SELECT *@ query, but
510−-- sometimes we're only interested in a subset of the columns of a table. To
511−-- restrict the returned columns, we can specify a projection by using 'Query's
512−-- @Functor@ instance:
513−--
514−-- >>> select c $ projectName <$> each projectSchema
515−-- ["rel8","aeson","text"]
516−
517−-- $guideJoins
518−--
519−-- Another common operation in relational databases is to take the @JOIN@ of
520−-- multiple tables. Rel8 doesn't have a specific join operation, but we can
521−-- recover the functionality of a join by selecting all rows of two tables, and
522−-- then using 'where_' to filter them.
523−--
524−-- To see how this works, first let's look at taking the product of two tables.
525−-- We can do this by simply calling 'each' twice, and then returning a tuple of
526−-- their results.
527−--
528−-- >>> :{
529−-- mapM_ print =<< select c do
530−-- author <- each authorSchema
531−-- project <- each projectSchema
532−-- return (projectName project, authorName author)
533−-- :}
534−-- ("rel8","Ollie")
535−-- ("rel8","Bryan O'Sullivan")
536−-- ("rel8","Emily Pillmore")
537−-- ("aeson","Ollie")
538−-- ("aeson","Bryan O'Sullivan")
539−-- ("aeson","Emily Pillmore")
540−-- ("text","Ollie")
541−-- ("text","Bryan O'Sullivan")
542−-- ("text","Emily Pillmore")
543−--
544−-- This isn't quite right, though, as we have ended up pairing up the wrong
545−-- projects and authors. To fix this, we can use 'where_' to restrict the
546−-- returned rows. We could write:
547−--
548−-- > select c $ do
549−-- > author <- each authorSchema
550−-- > project <- each projectSchema
551−-- > where_ $ projectAuthorId project ==. authorId author
552−-- > return (project, author)
553−--
554−-- but doing this every time you need a join can obscure the meaning of the
555−-- query you're writing. A good practice is to introduce specialised functions
556−-- for the particular joins in your database. In our case, this would be:
557−--
558−-- >>> :{
559−-- projectsForAuthor :: Author Expr -> Query (Project Expr)
560−-- projectsForAuthor a = each projectSchema >>= filter \p ->
561−-- projectAuthorId p ==. authorId a
562−-- :}
563−--
564−-- Our final query is then:
565−--
566−-- >>> :{
567−-- mapM_ print =<< select c do
568−-- author <- each authorSchema
569−-- project <- projectsForAuthor author
570−-- return (projectName project, authorName author)
571−-- :}
572−-- ("rel8","Ollie")
573−-- ("aeson","Bryan O'Sullivan")
574−-- ("text","Bryan O'Sullivan")
575−--
576−-- == @LEFT JOIN@s
577−--
578−-- Rel8 is also capable of performing @LEFT JOIN@s. To perform @LEFT JOIN@s, we
579−-- follow the same approach as before, but use the 'optional' query transformer
580−-- to allow for the possibility of the join to fail.
581−--
582−-- In our test database, we can see that there's another author who we haven't
583−-- seen yet:
584−--
585−-- >>> select c $ authorName <$> each authorSchema
586−-- ["Ollie","Bryan O'Sullivan","Emily Pillmore"]
587−--
588−-- Emily wasn't returned in our earlier query because - in our database - she
589−-- doesn't have any registered projects. We can account for this partiality in
590−-- our original query by wrapping the @projectsForAuthor@ call with 'optional':
591−--
592−-- >>> :{
593−-- mapM_ print =<< select c do
594−-- author <- each authorSchema
595−-- mproject <- optional $ projectsForAuthor author
596−-- return (authorName author, projectName <$> mproject)
597−-- :}
598−-- ("Ollie",Just "rel8")
599−-- ("Bryan O'Sullivan",Just "aeson")
600−-- ("Bryan O'Sullivan",Just "text")
601−-- ("Emily Pillmore",Nothing)
602
452
603−-- $guideAggregation
453+-- $adts
604−--
454+-- Algebraic data types can be modelled between Haskell and SQL.
605−-- Aggregations are operations like @sum@ and @count@ - operations that reduce
606−-- multiple rows to single values. To perform aggregations in Rel8, we can use
607−-- the 'aggregate' function, which takes a 'Query' of aggregated expressions,
608−-- runs the aggregation, and returns aggregated rows.
609−--
610−-- To start, let's look at a simple aggregation that tells us how many projects
611−-- exist:
612--
455--
613−-- >>> error "TODO"
456+-- * Your SQL table needs a certain text field that tags which Haskell constructor is in use.
457+-- * You have to use a few combinators to specify the sum type's individual constructors.
458+-- * If you want to do case analysis at the @Expr@ (SQL) level, you can use 'maybe'/'either'-like eliminators.
614--
459--
615−-- Rel8 is also capable of aggregating multiple rows into a single row by
460+-- The documentation in this section will assume a set of database types like this:
616−-- concatenating all rows as a list. This aggregation allows us to break free
617−-- of the row-orientated nature of SQL and write queries that return tree-like
618−-- structures. Earlier we saw an example of returning authors with their
619−-- projects, but the query didn't do a great job of describing the one-to-many
620−-- relationship between authors and their projects.
621--
461--
622−-- Let's look again at a query that returns authors and their projects, and
462+-- @
623−-- focus on the /type/ of that query.
463+-- data Thing f = ThingEmployer (Employer f) | ThingPotato (Potato f) | Nullary
464+-- deriving stock Generic
624--
465--
625−-- >>> :{
466+-- data Employer f = Employer { employerId :: f Int32, employerName :: f Text}
626−-- projectsForAuthor a = each projectSchema >>= filter \p ->
467+-- deriving stock Generic
627−-- projectAuthorId p ==. authorId a
468+-- deriving anyclass Rel8able
628−-- :}
629−--
630−-- >>> :{
631−-- let authorsAndProjects = do
632−-- author <- each authorSchema
633−-- project <- projectsForAuthor author
634−-- return (author, project)
635−-- where
636−-- :}
637−--
638−-- >>> :t select c authorsAndProjects
639−-- select c authorsAndProjects
640−-- :: MonadIO m => m [(Author Identity, Project Identity)]
641−--
642−-- Our query gives us a single list of pairs of authors and projects. However,
643−-- with our domain knowledge of the schema, this isn't a great type - what we'd
644−-- rather have is a list of pairs of authors and /lists/ of projects. That is,
645−-- what we'd like is:
646−--
647−-- > [(Author Identity, [Project Identity])]
648−--
649−-- This would be a much better type! Rel8 can produce a query with this type by
650−-- simply wrapping the call to @projectsForAuthor@ with either 'some' or
651−-- 'many'. Here we'll use 'many', which allows for the possibility of an author
652−-- to have no projects:
653--
469--
654−-- >>> :{
470+-- data Potato f = Potato { size :: f Int32, grower :: f Text }
655−-- mapM_ print =<< select c do
471+-- deriving stock Generic
656−-- author <- each authorSchema
472+-- deriving anyclass Rel8able
657−-- projectNames <- many $ projectName <$> projectsForAuthor author
473+-- @
658−-- return (authorName author, projectNames)
474+
475+-- $naming
476+--
477+-- First, in your 'TableSchema', name your type like this:
478+--
479+-- @
480+-- thingSchema :: TableSchema (ADT Thing Name)
481+-- thingSchema =
482+-- TableSchema
483+-- { schema = Nothing,
484+-- name = \"thing\",
485+-- columns =
486+-- nameADT @Thing
487+-- \"tag\"
488+-- Employer
489+-- { employerName = \"name\",
490+-- employerId = \"id\"
491+-- }
492+-- Potato {size = \"size\", grower = \"Mary\"}
493+-- }
494+-- @
495+--
496+-- Note that @nameADT \@Thing "tag"@ is variadic: it accepts one
497+-- argument per constructor, except the nullary ones (Nullary) because
498+-- there's nothing to do for them.
499+
500+-- $deconstruction
501+--
502+-- To deconstruct sum types at the SQL level, use 'deconstructADT',
503+-- which is also variadic, and has one argument for each
504+-- constructor. Similar to 'maybe'.
505+--
506+-- @
507+-- query :: Query (ADT Thing Expr)
508+-- query = do
509+-- thingExpr <- each thingSchema
510+-- where_ $
511+-- deconstructADT @Thing
512+-- (\employer -> employerName employer ==. lit \"Mary\")
513+-- (\potato -> grower potato ==. lit \"Mary\")
514+-- (lit False) -- Nullary case
515+-- thingExpr
516+-- pure thingExpr
517+-- @
518+--
519+-- SQL output:
520+--
521+-- @
522+-- SELECT
523+-- CAST("tag0_1" AS text) as "tag",
524+-- CAST("id1_1" AS int4) as "ThingEmployer/_1/employerId",
525+-- CAST("name2_1" AS text) as "ThingEmployer/_1/employerName",
526+-- CAST("size3_1" AS int4) as "ThingPotato/_1/size",
527+-- CAST("Mary4_1" AS text) as "ThingPotato/_1/grower"
528+-- FROM (SELECT
529+-- *
530+-- FROM (SELECT
531+-- "tag" as "tag0_1",
532+-- "id" as "id1_1",
533+-- "name" as "name2_1",
534+-- "size" as "size3_1",
535+-- "Mary" as "Mary4_1"
536+-- FROM "thing" as "T1") as "T1"
537+-- WHERE (CASE WHEN ("tag0_1") = (CAST(E'ThingPotato' AS text)) THEN ("Mary4_1") = (CAST(E'Mary' AS text))
538+-- WHEN ("tag0_1") = (CAST(E'Nullary' AS text)) THEN CAST(FALSE AS bool) ELSE ("name2_1") = (CAST(E'Mary' AS text)) END)) as "T1"
539+-- @
540+
541+-- $construction
542+--
543+-- To construct an ADT, you can use 'buildADT' or 'constructADT'. Consider the following type:
544+--
545+-- @
546+-- data Task f = Pending | Complete (CompletedTask f)
547+-- @
548+--
549+-- 'buildADT' is for constructing values of 'Task' in the 'Expr'
550+-- context. 'buildADT' needs two type-level arguments before its type
551+-- makes any sense. The first argument is the type of the "ADT", which
552+-- in our case is 'Task'. The second is the name of the constructor we
553+-- want to use. So that means we have the following possible
554+-- instantiations of 'buildADT' for 'Task':
555+--
556+-- @
557+-- > :t buildADT @Task @\"Pending\"
558+-- buildADT @Task @\"Pending\" :: ADT Task Expr
559+-- > :t buildADT @Task @\"Complete\"
560+-- buildADT @Task @\"Complete\" :: CompletedTask Expr -> ADT Task Expr
561+-- @
562+--
563+-- Note that as the "Pending" constructor has no fields, @buildADT
564+-- \@Task \@"Pending"@ is equivalent to @lit Pending@. But @buildADT
565+-- \@Task \@"Complete"@ is not the same as @lit . Complete@:
566+--
567+-- @
568+-- > :t lit . Complete
569+-- lit . Complete :: CompletedTask Result -> ADT Task Expr
570+-- @
571+--
572+--
573+-- Note that the former takes a @CompletedTask Expr@ while the latter
574+-- takes a @CompletedTask Result@. The former is more powerful because
575+-- you can construct @Task@s using dynamic values coming a database
576+-- query.
577+--
578+-- To show what this can look like in SQL, consider:
579+--
580+-- @
581+-- > :{
582+-- showQuery $ values
583+-- [ buildADT @Task @\"Pending\"
584+-- , buildADT @Task @\"Complete\" CompletedTask {date = Rel8.Expr.Time.now}
585+-- ]
659-- :}
586-- :}
660−-- ("Ollie",["rel8"])
587+-- @
661−-- ("Bryan O'Sullivan",["aeson","text"])
588+--
662−-- ("Emily Pillmore",[])
589+-- This produces the following SQL:
590+--
591+-- @
592+-- SELECT
593+-- CAST(\"values0_1\" AS text) as \"tag\",
594+-- CAST(\"values1_1\" AS timestamptz) as \"Complete/_1/date\"
595+-- FROM (SELECT
596+-- *
597+-- FROM (SELECT \"column1\" as \"values0_1\",
598+-- \"column2\" as \"values1_1\"
599+-- FROM
600+-- (VALUES
601+-- (CAST(E'Pending' AS text),CAST(NULL AS timestamptz)),
602+-- (CAST(E'Complete' AS text),CAST(now() AS timestamptz))) as \"V\") as \"T1\") as \"T1\"
603+-- @
604+--
605+-- This is what you get if you run it in @psql@:
606+--
607+--
608+-- @
609+-- tag | Complete/_1/date
610+-- ----------+-------------------------------
611+-- Pending |
612+-- Complete | 2022-05-19 21:28:23.969065+00
613+-- (2 rows)
614+-- @
615+--
616+-- "constructADT" is less convenient but more general alternative to
617+-- "buildADT". It requires only one type-level argument for its type
618+-- to make sense:
619+--
620+-- @
621+-- > :t constructADT @Task
622+-- constructADT @Task
623+-- :: (forall r. r -> (CompletedTask Expr -> r) -> r) -> ADT Task Expr
624+-- @
625+--
626+-- This might still seem a bit opaque, but basically it gives you a
627+-- Church-encoded constructor for arbitrary algebraic data types. You
628+-- might use it as follows:
629+--
630+-- @
631+-- let
632+-- pending :: ADT Task Expr
633+-- pending = constructADT @Task $ \pending _complete -> pending
634+--
635+-- complete :: ADT Task Expr
636+-- complete = constructADT @Task $ \_pending complete -> complete CompletedTask {date = Rel8.Expr.Time.now}
637+-- @
638+--
639+-- These values are otherwise identical to the ones we saw above with
640+-- @buildADT@, it's just a different style of constructing them.
641+--
642+
643+-- $misc-notes
644+--
645+-- 1. Note that the order of the arguments for all of these functions
646+-- is determined by the order of the constructors in the data
647+-- definition. If it were @data Task = Complete (CompletedTask f) |
648+-- Pending@ then the order of all the invocations of @constructADT@
649+-- and @deconstructADT@ would need to change.
650+--
651+-- 2. Maybe this is obvious, but just to spell it out: once you're in
652+-- the @Result@ context, you can of course construct @Task@ values
653+-- normally and use standard Haskell pattern-matching. @constructADT@
654+-- and @deconstructADT@ are specifically only needed in the @Expr@
655+-- context, and they allow you to do the equivalent of pattern
656+-- matching in PostgreSQL.
src/Rel8/Aggregate.hs+59−49
@@ -1,73 +1,83 @@
1−{-# language DerivingVia #-}
1+{-# language DataKinds #-}
2−{-# language GeneralizedNewtypeDeriving #-}
2+{-# language FlexibleContexts #-}
3+{-# language FlexibleInstances #-}
4+{-# language MultiParamTypeClasses #-}
3−{-# language NamedFieldPuns #-}
5+{-# language RankNTypes #-}
4{-# language StandaloneKindSignatures #-}
6{-# language StandaloneKindSignatures #-}
7+{-# language TypeFamilies #-}
8+{-# language UndecidableInstances #-}
5
9
6module Rel8.Aggregate
10module Rel8.Aggregate
7− ( Aggregate(..), foldInputs, mapInputs
11+ ( Aggregate(..), zipOutputs
8− , Aggregator(..), unsafeMakeAggregate
12+ , unsafeMakeAggregate
13+ , Aggregates
9 )
14 )
10where
15where
11
16
12-- base
17-- base
13−import Data.Functor.Const ( Const( Const ), getConst )
18+import Control.Applicative ( liftA2 )
14−import Data.Kind ( Type )
19+import Data.Functor.Identity ( Identity( Identity ) )
20+import Data.Kind ( Constraint, Type )
15import Prelude
21import Prelude
16
22
23+-- profunctors
24+import Data.Profunctor ( dimap )
25+
17-- opaleye
26-- opaleye
18−import qualified Opaleye.Internal.Aggregate as Opaleye
27+import qualified Opaleye.Aggregate as Opaleye
19import qualified Opaleye.Internal.HaskellDB.PrimQuery as Opaleye
28import qualified Opaleye.Internal.HaskellDB.PrimQuery as Opaleye
20−import qualified Opaleye.Internal.PackMap as Opaleye
29+import qualified Opaleye.Internal.Column as Opaleye
30+
31+-- rel8
32+import Rel8.Expr ( Expr )
33+import Rel8.Schema.HTable.Identity ( HIdentity(..) )
34+import qualified Rel8.Schema.Kind as K
35+import Rel8.Schema.Null ( Sql )
36+import Rel8.Table
37+ ( Table, Columns, Context, fromColumns, toColumns
38+ , FromExprs, fromResult, toResult
39+ , Transpose
40+ )
41+import Rel8.Table.Transpose ( Transposes )
42+import Rel8.Type ( DBType )
21
43
22−-- semigroupoids
23−import Data.Functor.Apply ( Apply, WrappedApplicative(..) )
24
44
45+-- | 'Aggregate' is a special context used by 'Rel8.aggregate'.
46+type Aggregate :: K.Context
47+newtype Aggregate a = Aggregate (Opaleye.Aggregator () (Expr a))
25
48
26−-- | An @Aggregate a@ describes how to aggregate @Table@s of type @a@. You can
27−-- unpack an @Aggregate@ back to @a@ by running it with 'aggregate'. As
28−-- @Aggregate@ is almost an 'Applicative' functor - but there is no 'pure'
29−-- operation. This means 'Aggregate' is an instance of 'Apply', and you can
30−-- combine @Aggregate@s using the @<.>@ combinator.
31−type Aggregate :: Type -> Type
32−newtype Aggregate a = Aggregate (Opaleye.Aggregator () a)
33− deriving newtype Functor
34− deriving Apply via (WrappedApplicative (Opaleye.Aggregator ()))
35
49
50+instance Sql DBType a => Table Aggregate (Aggregate a) where
51+ type Columns (Aggregate a) = HIdentity a
52+ type Context (Aggregate a) = Aggregate
53+ type FromExprs (Aggregate a) = a
54+ type Transpose to (Aggregate a) = to a
36
55
37−foldInputs :: Monoid b
56+ toColumns = HIdentity
38− => (Maybe Aggregator -> Opaleye.PrimExpr -> b) -> Aggregate a -> b
57+ fromColumns (HIdentity a) = a
39−foldInputs f (Aggregate (Opaleye.Aggregator (Opaleye.PackMap agg))) =
58+ toResult = HIdentity . Identity
40− getConst $ flip agg () $ \(aggregator, a) ->
59+ fromResult (HIdentity (Identity a)) = a
41− Const $ f (detuplize <$> aggregator) a
42− where
43− detuplize (operation, ordering, distinction) =
44− Aggregator {operation, ordering, distinction}
45
60
46
61
47−mapInputs :: ()
62+-- | @Aggregates a b@ means that the columns in @a@ are all 'Aggregate's
48− => (Opaleye.PrimExpr -> Opaleye.PrimExpr) -> Aggregate a -> Aggregate a
63+-- for the 'Expr' columns in @b@.
49−mapInputs transform (Aggregate (Opaleye.Aggregator (Opaleye.PackMap agg))) =
64+type Aggregates :: Type -> Type -> Constraint
50− Aggregate $ Opaleye.Aggregator $ Opaleye.PackMap $ agg . \f input ->
65+class Transposes Aggregate Expr aggregates exprs => Aggregates aggregates exprs
51− f (fmap transform input)
66+instance Transposes Aggregate Expr aggregates exprs => Aggregates aggregates exprs
52
67
53
68
54−type Aggregator :: Type
69+zipOutputs :: ()
55−data Aggregator = Aggregator
70+ => (Expr a -> Expr b -> Expr c) -> Aggregate a -> Aggregate b -> Aggregate c
56− { operation :: Opaleye.AggrOp
71+zipOutputs f (Aggregate a) (Aggregate b) = Aggregate (liftA2 f a b)
57− , ordering :: [Opaleye.OrderExpr]
58− , distinction :: Opaleye.AggrDistinct
59− }
60
72
61
73
62−unsafeMakeAggregate :: ()
74+unsafeMakeAggregate :: forall (input :: Type) (output :: Type) n n' a a'. ()
63− => (input -> Opaleye.PrimExpr)
75+ => (Expr input -> Opaleye.PrimExpr)
64− -> (Opaleye.PrimExpr -> output)
76+ -> (Opaleye.PrimExpr -> Expr output)
65− -> Maybe Aggregator
77+ -> Opaleye.Aggregator (Opaleye.Field_ n a) (Opaleye.Field_ n' a')
66− -> input
78+ -> Expr input
67 -> Aggregate output
79 -> Aggregate output
68unsafeMakeAggregate input output aggregator expr =
80unsafeMakeAggregate input output aggregator expr =
69− Aggregate $ Opaleye.Aggregator $ Opaleye.PackMap $ \f _ ->
81+ Aggregate $ dimap in_ out aggregator
70− output <$> f (tuplize <$> aggregator, input expr)
82+ where out = output . Opaleye.unColumn
71− where
83+ in_ = Opaleye.Column . input . const expr
72− tuplize Aggregator {operation, ordering, distinction} =
73− (operation, ordering, distinction)
src/Rel8/Column.hsnew file+31
@@ -0,0 +1,31 @@
1+{-# language DataKinds #-}
2+{-# language StandaloneKindSignatures #-}
3+{-# language TypeFamilies #-}
4+
5+module Rel8.Column
6+ ( Column
7+ , TColumn
8+ )
9+where
10+
11+-- base
12+import Data.Kind ( Type )
13+import Prelude ()
14+
15+-- rel8
16+import Rel8.FCF ( Eval, Exp )
17+import qualified Rel8.Schema.Kind as K
18+import Rel8.Schema.Result ( Result )
19+
20+
21+-- | This type family is used to specify columns in 'Rel8able's. In @Column f
22+-- a@, @f@ is the context of the column (which should be left polymorphic in
23+-- 'Rel8able' definitions), and @a@ is the type of the column.
24+type Column :: K.Context -> Type -> Type
25+type family Column context a where
26+ Column Result a = a
27+ Column context a = context a
28+
29+
30+data TColumn :: K.Context -> Type -> Exp Type
31+type instance Eval (TColumn f a) = Column f a
src/Rel8/Column/ADT.hsnew file+23
@@ -0,0 +1,23 @@
1+{-# language DataKinds #-}
2+{-# language StandaloneKindSignatures #-}
3+{-# language TypeFamilies #-}
4+
5+module Rel8.Column.ADT
6+ ( HADT
7+ )
8+where
9+
10+-- base
11+import Data.Kind ( Type )
12+import Prelude ()
13+
14+-- rel8
15+import qualified Rel8.Schema.Kind as K
16+import Rel8.Schema.Result ( Result )
17+import Rel8.Table.ADT ( ADT )
18+
19+
20+type HADT :: K.Context -> K.Rel8able -> Type
21+type family HADT context t where
22+ HADT Result t = t Result
23+ HADT context t = ADT t context
src/Rel8/Column/Either.hsnew file+26
@@ -0,0 +1,26 @@
1+{-# language DataKinds #-}
2+{-# language StandaloneKindSignatures #-}
3+{-# language TypeFamilyDependencies #-}
4+
5+module Rel8.Column.Either
6+ ( HEither
7+ )
8+where
9+
10+-- base
11+import Data.Kind ( Type )
12+import Prelude
13+
14+-- rel8
15+import qualified Rel8.Schema.Kind as K
16+import Rel8.Schema.Result ( Result )
17+import Rel8.Table.Either ( EitherTable )
18+
19+
20+-- | Nest an 'Either' value within a 'Rel8able'. @HEither f a b@ will produce a
21+-- 'EitherTable' @a b@ in the 'Expr' context, and a 'Either' @a b@ in the
22+-- 'Result' context.
23+type HEither :: K.Context -> Type -> Type -> Type
24+type family HEither context = either | either -> context where
25+ HEither Result = Either
26+ HEither context = EitherTable context
src/Rel8/Column/Lift.hsnew file+23
@@ -0,0 +1,23 @@
1+{-# language DataKinds #-}
2+{-# language StandaloneKindSignatures #-}
3+{-# language TypeFamilies #-}
4+
5+module Rel8.Column.Lift
6+ ( Lift
7+ )
8+where
9+
10+-- base
11+import Data.Kind ( Type )
12+import Prelude ()
13+
14+-- rel8
15+import qualified Rel8.Schema.Kind as K
16+import Rel8.Schema.Result ( Result )
17+import Rel8.Table.HKD ( HKD )
18+
19+
20+type Lift :: K.Context -> Type -> Type
21+type family Lift context a where
22+ Lift Result a = a
23+ Lift context a = HKD a context
src/Rel8/Column/List.hsnew file+25
@@ -0,0 +1,25 @@
1+{-# language DataKinds #-}
2+{-# language StandaloneKindSignatures #-}
3+{-# language TypeFamilyDependencies #-}
4+
5+module Rel8.Column.List
6+ ( HList
7+ )
8+where
9+
10+-- base
11+import Data.Kind ( Type )
12+import Prelude ()
13+
14+-- rel8
15+import qualified Rel8.Schema.Kind as K
16+import Rel8.Schema.Result ( Result )
17+import Rel8.Table.List ( ListTable )
18+
19+
20+-- | Nest a list within a 'Rel8able'. @HList f a@ will produce a 'ListTable'
21+-- @a@ in the 'Expr' context, and a @[a]@ in the 'Result' context.
22+type HList :: K.Context -> Type -> Type
23+type family HList context = list | list -> context where
24+ HList Result = []
25+ HList context = ListTable context
src/Rel8/Column/Maybe.hsnew file+26
@@ -0,0 +1,26 @@
1+{-# language DataKinds #-}
2+{-# language StandaloneKindSignatures #-}
3+{-# language TypeFamilyDependencies #-}
4+
5+module Rel8.Column.Maybe
6+ ( HMaybe
7+ )
8+where
9+
10+-- base
11+import Data.Kind ( Type )
12+import Prelude
13+
14+-- rel8
15+import qualified Rel8.Schema.Kind as K
16+import Rel8.Schema.Result ( Result )
17+import Rel8.Table.Maybe ( MaybeTable )
18+
19+
20+-- | Nest a 'Maybe' value within a 'Rel8able'. @HMaybe f a@ will produce a
21+-- 'MaybeTable' @a@ in the 'Expr' context, and a 'Maybe' @a@ in the 'Result'
22+-- context.
23+type HMaybe :: K.Context -> Type -> Type
24+type family HMaybe context = maybe | maybe -> context where
25+ HMaybe Result = Maybe
26+ HMaybe context = MaybeTable context
src/Rel8/Column/NonEmpty.hsnew file+27
@@ -0,0 +1,27 @@
1+{-# language DataKinds #-}
2+{-# language StandaloneKindSignatures #-}
3+{-# language TypeFamilyDependencies #-}
4+
5+module Rel8.Column.NonEmpty
6+ ( HNonEmpty
7+ )
8+where
9+
10+-- base
11+import Data.Kind ( Type )
12+import Data.List.NonEmpty ( NonEmpty )
13+import Prelude ()
14+
15+-- rel8
16+import qualified Rel8.Schema.Kind as K
17+import Rel8.Schema.Result ( Result )
18+import Rel8.Table.NonEmpty ( NonEmptyTable )
19+
20+
21+-- | Nest a 'NonEmpty' list within a 'Rel8able'. @HNonEmpty f a@ will produce a
22+-- 'NonEmptyTable' @a@ in the 'Expr' context, and a 'NonEmpty' @a@ in the
23+-- 'Result' context.
24+type HNonEmpty :: K.Context -> Type -> Type
25+type family HNonEmpty context = nonEmpty | nonEmpty -> context where
26+ HNonEmpty Result = NonEmpty
27+ HNonEmpty context = NonEmptyTable context
src/Rel8/Column/Null.hsnew file+26
@@ -0,0 +1,26 @@
1+{-# language DataKinds #-}
2+{-# language StandaloneKindSignatures #-}
3+{-# language TypeFamilyDependencies #-}
4+
5+module Rel8.Column.Null
6+ ( HNull
7+ )
8+where
9+
10+-- base
11+import Data.Kind ( Type )
12+import Prelude
13+
14+-- rel8
15+import qualified Rel8.Schema.Kind as K
16+import Rel8.Schema.Result ( Result )
17+import Rel8.Table.Null ( NullTable )
18+
19+
20+-- | Nest a 'Null' value within a 'Rel8able'. @HNull f a@ will produce a
21+-- 'NullTable' @a@ in the 'Expr' context, and a @'Maybe' a@ in the 'Result'
22+-- context.
23+type HNull :: K.Context -> Type -> Type
24+type family HNull context = maybe | maybe -> context where
25+ HNull Result = Maybe
26+ HNull context = NullTable context
src/Rel8/Column/These.hsnew file+29
@@ -0,0 +1,29 @@
1+{-# language DataKinds #-}
2+{-# language StandaloneKindSignatures #-}
3+{-# language TypeFamilyDependencies #-}
4+
5+module Rel8.Column.These
6+ ( HThese
7+ )
8+where
9+
10+-- base
11+import Data.Kind ( Type )
12+import Prelude ()
13+
14+-- rel8
15+import qualified Rel8.Schema.Kind as K
16+import Rel8.Schema.Result ( Result )
17+import Rel8.Table.These ( TheseTable )
18+
19+-- these
20+import Data.These ( These )
21+
22+
23+-- | Nest an 'These' value within a 'Rel8able'. @HThese f a b@ will produce a
24+-- 'TheseTable' @a b@ in the 'Expr' context, and a 'These' @a b@ in the
25+-- 'Result' context.
26+type HThese :: K.Context -> Type -> Type -> Type
27+type family HThese context = these | these -> context where
28+ HThese Result = These
29+ HThese context = TheseTable context
src/Rel8/Expr.hs+57−19
@@ -1,11 +1,12 @@
1{-# language DataKinds #-}
1{-# language DataKinds #-}
2{-# language DerivingStrategies #-}
2{-# language DerivingStrategies #-}
3{-# language FlexibleContexts #-}
3{-# language FlexibleContexts #-}
4−{-# language GADTs #-}
4+{-# language FlexibleInstances #-}
5−{-# language RoleAnnotations #-}
5+{-# language MultiParamTypeClasses #-}
6{-# language ScopedTypeVariables #-}
6{-# language ScopedTypeVariables #-}
7{-# language StandaloneKindSignatures #-}
7{-# language StandaloneKindSignatures #-}
8{-# language TypeApplications #-}
8{-# language TypeApplications #-}
9+{-# language TypeFamilies #-}
9{-# language UndecidableInstances #-}
10{-# language UndecidableInstances #-}
10
11
11module Rel8.Expr
12module Rel8.Expr
@@ -14,7 +15,7 @@ module Rel8.Expr
14where
15where
15
16
16-- base
17-- base
17−import Data.Kind ( Type )
18+import Data.Functor.Identity ( Identity( Identity ) )
18import Data.String ( IsString, fromString )
19import Data.String ( IsString, fromString )
19import Prelude hiding ( null )
20import Prelude hiding ( null )
20
21
@@ -22,7 +23,8 @@ import Prelude hiding ( null )
22import qualified Opaleye.Internal.HaskellDB.PrimQuery as Opaleye
23import qualified Opaleye.Internal.HaskellDB.PrimQuery as Opaleye
23
24
24-- rel8
25-- rel8
25−import Rel8.Expr.Null ( liftOpNullable, nullify )
26+import Rel8.Expr.Function ( function, nullaryFunction )
27+import Rel8.Expr.Null ( liftOpNull, nullify )
26import Rel8.Expr.Opaleye
28import Rel8.Expr.Opaleye
27 ( castExpr
29 ( castExpr
28 , fromPrimExpr
30 , fromPrimExpr
@@ -30,41 +32,44 @@ import Rel8.Expr.Opaleye
30 , zipPrimExprsWith
32 , zipPrimExprsWith
31 )
33 )
32import Rel8.Expr.Serialize ( litExpr )
34import Rel8.Expr.Serialize ( litExpr )
33−import Rel8.Schema.Nullability
35+import Rel8.Schema.HTable.Identity ( HIdentity( HIdentity ) )
34− ( Nullability( Nullable, NonNullable )
36+import qualified Rel8.Schema.Kind as K
35− , Sql, nullabilization
37+import Rel8.Schema.Null ( Nullity( Null, NotNull ), Sql, nullable )
38+import Rel8.Table
39+ ( Table, Columns, Context, fromColumns, toColumns
40+ , FromExprs, fromResult, toResult
41+ , Transpose
36 )
42 )
37import Rel8.Type ( DBType )
43import Rel8.Type ( DBType )
38import Rel8.Type.Monoid ( DBMonoid, memptyExpr )
44import Rel8.Type.Monoid ( DBMonoid, memptyExpr )
39−import Rel8.Type.Num ( DBFractional, DBNum )
45+import Rel8.Type.Num ( DBFloating, DBFractional, DBNum )
40import Rel8.Type.Semigroup ( DBSemigroup, (<>.) )
46import Rel8.Type.Semigroup ( DBSemigroup, (<>.) )
41
47
42
48
43-- | Typed SQL expressions.
49-- | Typed SQL expressions.
44−type role Expr representational
50+type Expr :: K.Context
45−type Expr :: Type -> Type
46newtype Expr a = Expr Opaleye.PrimExpr
51newtype Expr a = Expr Opaleye.PrimExpr
47 deriving stock Show
52 deriving stock Show
48
53
49
54
50instance Sql DBSemigroup a => Semigroup (Expr a) where
55instance Sql DBSemigroup a => Semigroup (Expr a) where
51− (<>) = case nullabilization @a of
56+ (<>) = case nullable @a of
52− Nullable -> liftOpNullable (<>.)
57+ Null -> liftOpNull (<>.)
53− NonNullable -> (<>.)
58+ NotNull -> (<>.)
54 {-# INLINABLE (<>) #-}
59 {-# INLINABLE (<>) #-}
55
60
56
61
57instance Sql DBMonoid a => Monoid (Expr a) where
62instance Sql DBMonoid a => Monoid (Expr a) where
58− mempty = case nullabilization @a of
63+ mempty = case nullable @a of
59− Nullable -> nullify memptyExpr
64+ Null -> nullify memptyExpr
60− NonNullable -> memptyExpr
65+ NotNull -> memptyExpr
61 {-# INLINABLE mempty #-}
66 {-# INLINABLE mempty #-}
62
67
63
68
64instance (Sql IsString a, Sql DBType a) => IsString (Expr a) where
69instance (Sql IsString a, Sql DBType a) => IsString (Expr a) where
65− fromString = litExpr . case nullabilization @a of
70+ fromString = litExpr . case nullable @a of
66− Nullable -> Just . fromString
71+ Null -> Just . fromString
67− NonNullable -> fromString
72+ NotNull -> fromString
68
73
69
74
70instance Sql DBNum a => Num (Expr a) where
75instance Sql DBNum a => Num (Expr a) where
@@ -85,3 +90,36 @@ instance Sql DBFractional a => Fractional (Expr a) where
85
90
86 fromRational =
91 fromRational =
87 castExpr . Expr . Opaleye.ConstExpr . Opaleye.NumericLit . realToFrac
92 castExpr . Expr . Opaleye.ConstExpr . Opaleye.NumericLit . realToFrac
93+
94+
95+instance Sql DBFloating a => Floating (Expr a) where
96+ pi = nullaryFunction "PI"
97+ exp = function "exp"
98+ log = function "ln"
99+ sqrt = function "sqrt"
100+ (**) = zipPrimExprsWith (Opaleye.BinExpr (Opaleye.:^))
101+ logBase = function "log"
102+ sin = function "sin"
103+ cos = function "cos"
104+ tan = function "tan"
105+ asin = function "asin"
106+ acos = function "acos"
107+ atan = function "atan"
108+ sinh = function "sinh"
109+ cosh = function "cosh"
110+ tanh = function "tanh"
111+ asinh = function "asinh"
112+ acosh = function "acosh"
113+ atanh = function "atanh"
114+
115+
116+instance Sql DBType a => Table Expr (Expr a) where
117+ type Columns (Expr a) = HIdentity a
118+ type Context (Expr a) = Expr
119+ type FromExprs (Expr a) = a
120+ type Transpose to (Expr a) = to a
121+
122+ toColumns a = HIdentity a
123+ fromColumns (HIdentity a) = a
124+ toResult a = HIdentity (Identity a)
125+ fromResult (HIdentity (Identity a)) = a
src/Rel8/Expr.hs-boot+5−4
@@ -1,4 +1,4 @@
1−{-# language RoleAnnotations #-}
1+{-# language DataKinds #-}
2{-# language StandaloneKindSignatures #-}
2{-# language StandaloneKindSignatures #-}
3
3
4module Rel8.Expr
4module Rel8.Expr
@@ -7,13 +7,14 @@ module Rel8.Expr
7where
7where
8
8
9-- base
9-- base
10−import Data.Kind ( Type )
11import Prelude ()
10import Prelude ()
12
11
13-- opaleye
12-- opaleye
14import qualified Opaleye.Internal.HaskellDB.PrimQuery as Opaleye
13import qualified Opaleye.Internal.HaskellDB.PrimQuery as Opaleye
15
14
15+-- rel8
16+import Rel8.Schema.Kind ( Context )
16
17
17−type role Expr representational
18+
18−type Expr :: Type -> Type
19+type Expr :: Context
19newtype Expr a = Expr Opaleye.PrimExpr
20newtype Expr a = Expr Opaleye.PrimExpr
src/Rel8/Expr/Aggregate.hs+60−87
@@ -1,7 +1,6 @@
1{-# language DataKinds #-}
1{-# language DataKinds #-}
2{-# language FlexibleContexts #-}
2{-# language FlexibleContexts #-}
3{-# language ScopedTypeVariables #-}
3{-# language ScopedTypeVariables #-}
4−{-# language TypeApplications #-}
5{-# language TypeFamilies #-}
4{-# language TypeFamilies #-}
6
5
7{-# options_ghc -fno-warn-redundant-constraints #-}
6{-# options_ghc -fno-warn-redundant-constraints #-}
@@ -11,10 +10,11 @@ module Rel8.Expr.Aggregate
11 , and, or
10 , and, or
12 , min, max
11 , min, max
13 , sum, sumWhere
12 , sum, sumWhere
13+ , avg
14 , stringAgg
14 , stringAgg
15 , groupByExpr
15 , groupByExpr
16 , listAggExpr, nonEmptyAggExpr
16 , listAggExpr, nonEmptyAggExpr
17− , sgroupByExpr
17+ , slistAggExpr, snonEmptyAggExpr
18 )
18 )
19where
19where
20
20
@@ -24,10 +24,12 @@ import Data.List.NonEmpty ( NonEmpty )
24import Prelude hiding ( and, max, min, null, or, sum )
24import Prelude hiding ( and, max, min, null, or, sum )
25
25
26-- opaleye
26-- opaleye
27−import qualified Opaleye.Internal.HaskellDB.PrimQuery as Opaleye
27+import qualified Opaleye.Internal.Aggregate as Opaleye
28+import Opaleye.Internal.Column ( Field_( Column ) )
29+import qualified Opaleye.Aggregate as Opaleye
28
30
29-- rel8
31-- rel8
30−import Rel8.Aggregate ( Aggregate, Aggregator(..), unsafeMakeAggregate )
32+import Rel8.Aggregate ( Aggregate, unsafeMakeAggregate )
31import Rel8.Expr ( Expr )
33import Rel8.Expr ( Expr )
32import Rel8.Expr.Bool ( caseExpr )
34import Rel8.Expr.Bool ( caseExpr )
33import Rel8.Expr.Opaleye
35import Rel8.Expr.Opaleye
@@ -38,9 +40,11 @@ import Rel8.Expr.Opaleye
38 )
40 )
39import Rel8.Expr.Null ( null )
41import Rel8.Expr.Null ( null )
40import Rel8.Expr.Serialize ( litExpr )
42import Rel8.Expr.Serialize ( litExpr )
41−import Rel8.Schema.Nullability ( Nullability, Sql, nullabilization )
43+import Rel8.Schema.Null ( Sql, Unnullify )
44+import Rel8.Type ( DBType, typeInformation )
42−import Rel8.Type.Array ( fromPrimArray )
45+import Rel8.Type.Array ( encodeArrayElement )
43import Rel8.Type.Eq ( DBEq )
46import Rel8.Type.Eq ( DBEq )
47+import Rel8.Type.Information ( TypeInformation )
44import Rel8.Type.Num ( DBNum )
48import Rel8.Type.Num ( DBNum )
45import Rel8.Type.Ord ( DBMax, DBMin )
49import Rel8.Type.Ord ( DBMax, DBMin )
46import Rel8.Type.String ( DBString )
50import Rel8.Type.String ( DBString )
@@ -48,130 +52,99 @@ import Rel8.Type.Sum ( DBSum )
48
52
49
53
50-- | Count the occurances of a single column. Corresponds to @COUNT(a)@
54-- | Count the occurances of a single column. Corresponds to @COUNT(a)@
51−count :: Expr a -> Aggregate (Expr Int64)
55+count :: Expr a -> Aggregate Int64
52−count = unsafeMakeAggregate toPrimExpr fromPrimExpr $
56+count = unsafeMakeAggregate toPrimExpr fromPrimExpr Opaleye.count
53− Just Aggregator
54− { operation = Opaleye.AggrCount
55− , ordering = []
56− , distinction = Opaleye.AggrAll
57− }
58−
59
57
60-- | Count the number of distinct occurances of a single column. Corresponds to
58-- | Count the number of distinct occurances of a single column. Corresponds to
61-- @COUNT(DISTINCT a)@
59-- @COUNT(DISTINCT a)@
62−countDistinct :: DBEq a => Expr a -> Aggregate (Expr Int64)
60+countDistinct :: Sql DBEq a => Expr a -> Aggregate Int64
63countDistinct = unsafeMakeAggregate toPrimExpr fromPrimExpr $
61countDistinct = unsafeMakeAggregate toPrimExpr fromPrimExpr $
64− Just Aggregator
62+ Opaleye.distinctAggregator Opaleye.count
65− { operation = Opaleye.AggrCount
66− , ordering = []
67− , distinction = Opaleye.AggrDistinct
68− }
69
63
70
64
71-- | Corresponds to @COUNT(*)@.
65-- | Corresponds to @COUNT(*)@.
72−countStar :: Aggregate (Expr Int64)
66+countStar :: Aggregate Int64
73countStar = count (litExpr True)
67countStar = count (litExpr True)
74
68
75
69
70+-- | A count of the number of times a given expression is @true@.
76−countWhere :: Expr Bool -> Aggregate (Expr Int64)
71+countWhere :: Expr Bool -> Aggregate Int64
77countWhere condition = count (caseExpr [(condition, litExpr (Just True))] null)
72countWhere condition = count (caseExpr [(condition, litExpr (Just True))] null)
78
73
79
74
80-- | Corresponds to @bool_and@.
75-- | Corresponds to @bool_and@.
81−and :: Expr Bool -> Aggregate (Expr Bool)
76+and :: Expr Bool -> Aggregate Bool
82−and = unsafeMakeAggregate toPrimExpr fromPrimExpr $
77+and = unsafeMakeAggregate toPrimExpr fromPrimExpr Opaleye.boolAnd
83− Just Aggregator
84− { operation = Opaleye.AggrBoolAnd
85− , ordering = []
86− , distinction = Opaleye.AggrAll
87− }
88
78
89
79
90-- | Corresponds to @bool_or@.
80-- | Corresponds to @bool_or@.
91−or :: Expr Bool -> Aggregate (Expr Bool)
81+or :: Expr Bool -> Aggregate Bool
92−or = unsafeMakeAggregate toPrimExpr fromPrimExpr $
82+or = unsafeMakeAggregate toPrimExpr fromPrimExpr Opaleye.boolOr
93− Just Aggregator
94− { operation = Opaleye.AggrBoolOr
95− , ordering = []
96− , distinction = Opaleye.AggrAll
97− }
98
83
99
84
100-- | Produce an aggregation for @Expr a@ using the @max@ function.
85-- | Produce an aggregation for @Expr a@ using the @max@ function.
101−max :: Sql DBMax a => Expr a -> Aggregate (Expr a)
86+max :: Sql DBMax a => Expr a -> Aggregate a
102−max = unsafeMakeAggregate toPrimExpr fromPrimExpr $
87+max = unsafeMakeAggregate toPrimExpr fromPrimExpr Opaleye.unsafeMax
103− Just Aggregator
104− { operation = Opaleye.AggrSum
105− , ordering = []
106− , distinction = Opaleye.AggrAll
107− }
108
88
109
89
110-- | Produce an aggregation for @Expr a@ using the @max@ function.
90-- | Produce an aggregation for @Expr a@ using the @max@ function.
111−min :: Sql DBMin a => Expr a -> Aggregate (Expr a)
91+min :: Sql DBMin a => Expr a -> Aggregate a
112−min = unsafeMakeAggregate toPrimExpr fromPrimExpr $
92+min = unsafeMakeAggregate toPrimExpr fromPrimExpr Opaleye.unsafeMin
113− Just Aggregator
114− { operation = Opaleye.AggrSum
115− , ordering = []
116− , distinction = Opaleye.AggrAll
117− }
118
93
119-- | Corresponds to @sum@. Note that in SQL, @sum@ is type changing - for
94-- | Corresponds to @sum@. Note that in SQL, @sum@ is type changing - for
120-- example the @sum@ of @integer@ returns a @bigint@. Rel8 doesn't support
95-- example the @sum@ of @integer@ returns a @bigint@. Rel8 doesn't support
121−-- this, and will add explicit cast back to the original input type. This can
96+-- this, and will add explicit casts back to the original input type. This can
122-- lead to overflows, and if you anticipate very large sums, you should upcast
97-- lead to overflows, and if you anticipate very large sums, you should upcast
123-- your input.
98-- your input.
124−sum :: Sql DBSum a => Expr a -> Aggregate (Expr a)
99+sum :: Sql DBSum a => Expr a -> Aggregate a
125−sum = unsafeMakeAggregate toPrimExpr (castExpr . fromPrimExpr) $
100+sum = unsafeMakeAggregate toPrimExpr (castExpr . fromPrimExpr) Opaleye.unsafeSum
126− Just Aggregator
101+
127− { operation = Opaleye.AggrSum
128− , ordering = []
129− , distinction = Opaleye.AggrAll
130− }
131
102
103+-- | Corresponds to @avg@. Note that in SQL, @avg@ is type changing - for
104+-- example, the @avg@ of @integer@ returns a @numeric@. Rel8 doesn't support
105+-- this, and will add explicit casts back to the original input type. If you
106+-- need a fractional result on an integral column, you should cast your input
107+-- to 'Double' or 'Data.Scientific.Scientific' before calling 'avg'.
108+avg :: Sql DBSum a => Expr a -> Aggregate a
109+avg = unsafeMakeAggregate toPrimExpr (castExpr . fromPrimExpr) Opaleye.unsafeAvg
132
110
111+-- | Take the sum of all expressions that satisfy a predicate.
133sumWhere :: (Sql DBNum a, Sql DBSum a)
112sumWhere :: (Sql DBNum a, Sql DBSum a)
134− => Expr Bool -> Expr a -> Aggregate (Expr a)
113+ => Expr Bool -> Expr a -> Aggregate a
135sumWhere condition a = sum (caseExpr [(condition, a)] 0)
114sumWhere condition a = sum (caseExpr [(condition, a)] 0)
136
115
137
116
117+-- | Corresponds to @string_agg()@.
138stringAgg :: Sql DBString a
118stringAgg :: Sql DBString a
139− => Expr db -> Expr a -> Aggregate (Expr a)
119+ => Expr db -> Expr a -> Aggregate a
140stringAgg delimiter =
120stringAgg delimiter =
141− unsafeMakeAggregate toPrimExpr (castExpr . fromPrimExpr) $
121+ unsafeMakeAggregate toPrimExpr (castExpr . fromPrimExpr) (Opaleye.stringAgg (Column (toPrimExpr delimiter)))
142− Just Aggregator
143− { operation = Opaleye.AggrStringAggr (toPrimExpr delimiter)
144− , ordering = []
145− , distinction = Opaleye.AggrAll
146− }
147
122
148
123
149-- | Aggregate a value by grouping by it.
124-- | Aggregate a value by grouping by it.
150−groupByExpr :: Sql DBEq a => Expr a -> Aggregate (Expr a)
125+groupByExpr :: Sql DBEq a => Expr a -> Aggregate a
151−groupByExpr = sgroupByExpr nullabilization
126+groupByExpr = unsafeMakeAggregate toPrimExpr fromPrimExpr Opaleye.groupBy
152
127
153
128
129+-- | Collect expressions values as a list.
154−listAggExpr :: Expr a -> Aggregate (Expr [a])
130+listAggExpr :: Sql DBType a => Expr a -> Aggregate [a]
155−listAggExpr = unsafeMakeAggregate toPrimExpr from $ Just
131+listAggExpr = slistAggExpr typeInformation
156− Aggregator
157− { operation = Opaleye.AggrArr
158− , ordering = []
159− , distinction = Opaleye.AggrAll
160− }
161− where
162− from = fromPrimExpr . fromPrimArray
163
132
164
133
134+-- | Collect expressions values as a non-empty list.
165−nonEmptyAggExpr :: Expr a -> Aggregate (Expr (NonEmpty a))
135+nonEmptyAggExpr :: Sql DBType a => Expr a -> Aggregate (NonEmpty a)
166−nonEmptyAggExpr = unsafeMakeAggregate toPrimExpr from $ Just
136+nonEmptyAggExpr = snonEmptyAggExpr typeInformation
167− Aggregator
137+
168− { operation = Opaleye.AggrArr
138+
169− , ordering = []
139+slistAggExpr :: ()
170− , distinction = Opaleye.AggrAll
140+ => TypeInformation (Unnullify a) -> Expr a -> Aggregate [a]
171− }
141+slistAggExpr info = unsafeMakeAggregate to fromPrimExpr Opaleye.arrayAgg
172 where
142 where
173− from = fromPrimExpr . fromPrimArray
143+ to = encodeArrayElement info . toPrimExpr
174
144
175
145
176−sgroupByExpr :: DBEq db => Nullability db a -> Expr a -> Aggregate (Expr a)
146+snonEmptyAggExpr :: ()
147+ => TypeInformation (Unnullify a) -> Expr a -> Aggregate (NonEmpty a)
177−sgroupByExpr _ = unsafeMakeAggregate toPrimExpr fromPrimExpr Nothing
148+snonEmptyAggExpr info = unsafeMakeAggregate to fromPrimExpr Opaleye.arrayAgg
149+ where
150+ to = encodeArrayElement info . toPrimExpr
src/Rel8/Expr/Array.hs+19−14
@@ -1,13 +1,12 @@
1{-# language DataKinds #-}
1{-# language DataKinds #-}
2{-# language FlexibleContexts #-}
2{-# language FlexibleContexts #-}
3−{-# language ScopedTypeVariables #-}
4−{-# language TypeApplications #-}
5{-# language TypeFamilies #-}
3{-# language TypeFamilies #-}
6
4
7{-# options_ghc -fno-warn-redundant-constraints #-}
5{-# options_ghc -fno-warn-redundant-constraints #-}
8
6
9module Rel8.Expr.Array
7module Rel8.Expr.Array
10 ( listOf, nonEmptyOf
8 ( listOf, nonEmptyOf
9+ , slistOf, snonEmptyOf
11 , sappend, sappend1, sempty
10 , sappend, sappend1, sempty
12 )
11 )
13where
12where
@@ -26,28 +25,34 @@ import Rel8.Expr.Opaleye
26 , zipPrimExprsWith
25 , zipPrimExprsWith
27 )
26 )
28import Rel8.Type ( DBType, typeInformation )
27import Rel8.Type ( DBType, typeInformation )
29−import Rel8.Type.Array ( array, zipPrimArraysWith )
28+import Rel8.Type.Array ( array )
30import Rel8.Type.Information ( TypeInformation(..) )
29import Rel8.Type.Information ( TypeInformation(..) )
31−import Rel8.Schema.Nullability ( Unnullify, Nullability, Sql )
30+import Rel8.Schema.Null ( Unnullify, Sql )
32
31
33
32
34sappend :: Expr [a] -> Expr [a] -> Expr [a]
33sappend :: Expr [a] -> Expr [a] -> Expr [a]
35−sappend = zipPrimExprsWith (zipPrimArraysWith (Opaleye.BinExpr (Opaleye.:||)))
34+sappend = zipPrimExprsWith (Opaleye.BinExpr (Opaleye.:||))
36
35
37
36
38sappend1 :: Expr (NonEmpty a) -> Expr (NonEmpty a) -> Expr (NonEmpty a)
37sappend1 :: Expr (NonEmpty a) -> Expr (NonEmpty a) -> Expr (NonEmpty a)
39−sappend1 = zipPrimExprsWith (zipPrimArraysWith (Opaleye.BinExpr (Opaleye.:||)))
38+sappend1 = zipPrimExprsWith (Opaleye.BinExpr (Opaleye.:||))
40
39
41
40
42−sempty :: Nullability t a -> TypeInformation t -> Expr [a]
41+sempty :: TypeInformation (Unnullify a) -> Expr [a]
43−sempty _ info = fromPrimExpr $ array info []
42+sempty info = fromPrimExpr $ array info []
44
43
45
44
46−listOf :: forall a. Sql DBType a => [Expr a] -> Expr [a]
45+slistOf :: TypeInformation (Unnullify a) -> [Expr a] -> Expr [a]
47−listOf =
48− fromPrimExpr . array (typeInformation @(Unnullify a)) . fmap toPrimExpr
46+slistOf info = fromPrimExpr . array info . fmap toPrimExpr
49
47
50
48
51−nonEmptyOf :: forall a. Sql DBType a => NonEmpty (Expr a) -> Expr (NonEmpty a)
49+snonEmptyOf :: TypeInformation (Unnullify a) -> NonEmpty (Expr a) -> Expr (NonEmpty a)
52−nonEmptyOf =
53− fromPrimExpr . array (typeInformation @(Unnullify a)) . fmap toPrimExpr
50+snonEmptyOf info = fromPrimExpr . array info . fmap toPrimExpr
51+
52+
53+listOf :: Sql DBType a => [Expr a] -> Expr [a]
54+listOf = slistOf typeInformation
55+
56+
57+nonEmptyOf :: Sql DBType a => NonEmpty (Expr a) -> Expr (NonEmpty a)
58+nonEmptyOf = snonEmptyOf typeInformation
src/Rel8/Expr/Bool.hs+8−42
@@ -1,3 +1,5 @@
1+{-# language GADTs #-}
2+
1module Rel8.Expr.Bool
3module Rel8.Expr.Bool
2 ( false, true
4 ( false, true
3 , (&&.), (||.), not_
5 , (&&.), (||.), not_
@@ -17,7 +19,7 @@ import qualified Opaleye.Internal.HaskellDB.PrimQuery as Opaleye
17
19
18-- rel8
20-- rel8
19import {-# SOURCE #-} Rel8.Expr ( Expr( Expr ) )
21import {-# SOURCE #-} Rel8.Expr ( Expr( Expr ) )
20−import Rel8.Expr.Opaleye ( mapPrimExpr, zipPrimExprsWith )
22+import Rel8.Expr.Opaleye ( mapPrimExpr, toPrimExpr, zipPrimExprsWith )
21import Rel8.Expr.Serialize ( litExpr )
23import Rel8.Expr.Serialize ( litExpr )
22
24
23
25
@@ -32,68 +34,28 @@ true = litExpr True
32
34
33
35
34-- | The SQL @AND@ operator.
36-- | The SQL @AND@ operator.
35−--
36−-- >>> :{
37−-- mapM_ print =<< select c do
38−-- x <- values [lit True, lit False]
39−-- y <- values [lit True, lit False]
40−-- return (x, y, x &&. y)
41−-- :}
42−-- (True,True,True)
43−-- (True,False,False)
44−-- (False,True,False)
45−-- (False,False,False)
46(&&.) :: Expr Bool -> Expr Bool -> Expr Bool
37(&&.) :: Expr Bool -> Expr Bool -> Expr Bool
47(&&.) = zipPrimExprsWith (Opaleye.BinExpr Opaleye.OpAnd)
38(&&.) = zipPrimExprsWith (Opaleye.BinExpr Opaleye.OpAnd)
48infixr 3 &&.
39infixr 3 &&.
49
40
50
41
51-- | The SQL @OR@ operator.
42-- | The SQL @OR@ operator.
52−--
53−-- >>> :{
54−-- mapM_ print =<< select c do
55−-- x <- values [lit True, lit False]
56−-- y <- values [lit True, lit False]
57−-- return (x, y, x ||. y)
58−-- :}
59−-- (True,True,True)
60−-- (True,False,True)
61−-- (False,True,True)
62−-- (False,False,False)
63(||.) :: Expr Bool -> Expr Bool -> Expr Bool
43(||.) :: Expr Bool -> Expr Bool -> Expr Bool
64(||.) = zipPrimExprsWith (Opaleye.BinExpr Opaleye.OpOr)
44(||.) = zipPrimExprsWith (Opaleye.BinExpr Opaleye.OpOr)
65infixr 2 ||.
45infixr 2 ||.
66
46
67
47
68-- | The SQL @NOT@ operator.
48-- | The SQL @NOT@ operator.
69−--
70−-- >>> select c $ pure $ not_ $ lit True
71−-- [False]
72−--
73−-- >>> select c $ pure $ not_ $ lit False
74−-- [True]
75not_ :: Expr Bool -> Expr Bool
49not_ :: Expr Bool -> Expr Bool
76not_ = mapPrimExpr (Opaleye.UnExpr Opaleye.OpNot)
50not_ = mapPrimExpr (Opaleye.UnExpr Opaleye.OpNot)
77
51
78
52
79-- | Fold @AND@ over a collection of expressions.
53-- | Fold @AND@ over a collection of expressions.
80−--
81−-- >>> select c $ pure $ and_ [ lit True ==. lit False, lit False, lit True ]
82−-- [False]
83−--
84−-- >>> select c $ pure $ and_ []
85−-- [True]
86and_ :: Foldable f => f (Expr Bool) -> Expr Bool
54and_ :: Foldable f => f (Expr Bool) -> Expr Bool
87and_ = foldl' (&&.) true
55and_ = foldl' (&&.) true
88
56
89
57
90-- | Fold @OR@ over a collection of expressions.
58-- | Fold @OR@ over a collection of expressions.
91−--
92−-- >>> select c $ pure $ or_ [ lit True ==. lit False, lit False, lit True ]
93−-- [True]
94−--
95−-- >>> select c $ pure $ or_ []
96−-- [False]
97or_ :: Foldable f => f (Expr Bool) -> Expr Bool
59or_ :: Foldable f => f (Expr Bool) -> Expr Bool
98or_ = foldl' (||.) false
60or_ = foldl' (||.) false
99
61
@@ -115,9 +77,13 @@ caseExpr :: [(Expr Bool, Expr a)] -> Expr a -> Expr a
115caseExpr branches (Expr fallback) =
77caseExpr branches (Expr fallback) =
116 Expr $ Opaleye.CaseExpr (map go branches) fallback
78 Expr $ Opaleye.CaseExpr (map go branches) fallback
117 where
79 where
118− go (Expr condition, Expr value) = (condition, value)
80+ go (condition, value) = (toPrimExpr condition, toPrimExpr value)
119
81
120
82
83+-- | Convert a @Expr (Maybe Bool)@ to a @Expr Bool@ by treating @Nothing@ as
84+-- @False@. This can be useful when combined with 'Rel8.where_', which expects
85+-- a @Bool@, and produces expressions that optimize better than general case
86+-- analysis.
121coalesce :: Expr (Maybe Bool) -> Expr Bool
87coalesce :: Expr (Maybe Bool) -> Expr Bool
122coalesce (Expr a) = Expr a &&. Expr (Opaleye.FunExpr "COALESCE" [a, untrue])
88coalesce (Expr a) = Expr a &&. Expr (Opaleye.FunExpr "COALESCE" [a, untrue])
123 where
89 where
src/Rel8/Expr/Default.hsnew file+35
@@ -0,0 +1,35 @@
1+module Rel8.Expr.Default
2+ ( unsafeDefault
3+ )
4+where
5+
6+-- base
7+import Prelude ()
8+
9+-- opaleye
10+import qualified Opaleye.Internal.HaskellDB.PrimQuery as Opaleye
11+
12+-- rel8
13+import Rel8.Expr ( Expr )
14+import Rel8.Expr.Opaleye ( fromPrimExpr )
15+
16+
17+-- | Corresponds to the SQL @DEFAULT@ expression.
18+--
19+-- This 'Expr' is unsafe for numerous reasons, and should be used with care:
20+--
21+-- 1. This 'Expr' only makes sense in an @INSERT@ or @UPDATE@ statement.
22+--
23+-- 2. Rel8 is not able to verify that a particular column actually has a
24+-- @DEFAULT@ value. Trying to use @unsafeDefault@ where there is no default
25+-- will cause a runtime crash
26+--
27+-- 3. @DEFAULT@ values can not be transformed. For example, the innocuous Rel8
28+-- code @unsafeDefault + 1@ will crash, despite type checking.
29+--
30+-- Given all these caveats, we suggest avoiding the use of default values where
31+-- possible, instead being explicit. A common scenario where default values are
32+-- used is with auto-incrementing identifier columns. In this case, we suggest
33+-- using 'Rel8.nextval' instead.
34+unsafeDefault :: Expr a
35+unsafeDefault = fromPrimExpr Opaleye.DefaultInsertExpr
src/Rel8/Expr/Eq.hs+29−60
@@ -1,13 +1,13 @@
1{-# language FlexibleContexts #-}
1{-# language FlexibleContexts #-}
2{-# language GADTs #-}
2{-# language GADTs #-}
3−{-# language LambdaCase #-}
3+{-# language ScopedTypeVariables #-}
4+{-# language TypeApplications #-}
4{-# language ViewPatterns #-}
5{-# language ViewPatterns #-}
5
6
6{-# options_ghc -fno-warn-redundant-constraints #-}
7{-# options_ghc -fno-warn-redundant-constraints #-}
7
8
8module Rel8.Expr.Eq
9module Rel8.Expr.Eq
9− ( seq, sne
10− , (==.), (/=.)
10+ ( (==.), (/=.)
11 , (==?), (/=?)
11 , (==?), (/=?)
12 , in_
12 , in_
13 )
13 )
@@ -16,7 +16,7 @@ where
16-- base
16-- base
17import Data.Foldable ( toList )
17import Data.Foldable ( toList )
18import Data.List.NonEmpty ( nonEmpty )
18import Data.List.NonEmpty ( nonEmpty )
19−import Prelude hiding ( seq, sin )
19+import Prelude
20
20
21-- opaleye
21-- opaleye
22import qualified Opaleye.Internal.HaskellDB.PrimQuery as Opaleye
22import qualified Opaleye.Internal.HaskellDB.PrimQuery as Opaleye
@@ -24,12 +24,9 @@ import qualified Opaleye.Internal.HaskellDB.PrimQuery as Opaleye
24-- rel8
24-- rel8
25import Rel8.Expr ( Expr )
25import Rel8.Expr ( Expr )
26import Rel8.Expr.Bool ( (&&.), (||.), false, or_, coalesce )
26import Rel8.Expr.Bool ( (&&.), (||.), false, or_, coalesce )
27−import Rel8.Expr.Null ( isNull, unsafeLiftOpNullable )
27+import Rel8.Expr.Null ( isNull, unsafeLiftOpNull )
28import Rel8.Expr.Opaleye ( fromPrimExpr, toPrimExpr, zipPrimExprsWith )
28import Rel8.Expr.Opaleye ( fromPrimExpr, toPrimExpr, zipPrimExprsWith )
29−import Rel8.Schema.Nullability
29+import Rel8.Schema.Null ( Nullity( NotNull, Null ), Sql, nullable )
30− ( Nullability( NonNullable, Nullable )
31− , Sql, nullabilization
32− )
33import Rel8.Type.Eq ( DBEq )
30import Rel8.Type.Eq ( DBEq )
34
31
35
32
@@ -41,40 +38,18 @@ ne :: DBEq a => Expr a -> Expr a -> Expr Bool
41ne = zipPrimExprsWith (Opaleye.BinExpr (Opaleye.:<>))
38ne = zipPrimExprsWith (Opaleye.BinExpr (Opaleye.:<>))
42
39
43
40
44−seq :: DBEq db => Nullability db a -> Expr a -> Expr a -> Expr Bool
45−seq = \case
46− Nullable -> \ma mb -> isNull ma &&. isNull mb ||. ma ==? mb
47− NonNullable -> eq
48−
49−
50−sne :: DBEq db => Nullability db a -> Expr a -> Expr a -> Expr Bool
51−sne = \case
52− Nullable -> \ma mb -> isNull ma `ne` isNull mb ||. ma /=? mb
53− NonNullable -> ne
54−
55−
56−sin :: (DBEq db, Foldable f)
57− => Nullability db a -> f (Expr a) -> Expr a -> Expr Bool
58−sin nullability (toList -> as) a = case nullability of
59− Nullable -> or_ $ map (seq Nullable a) as
60− NonNullable -> case nonEmpty as of
61− Nothing -> false
62− Just xs ->
63− fromPrimExpr $
64− Opaleye.BinExpr Opaleye.OpIn
65− (toPrimExpr a)
66− (Opaleye.ListExpr (toPrimExpr <$> xs))
67−
68−
69-- | Compare two expressions for equality.
41-- | Compare two expressions for equality.
70--
42--
71-- This corresponds to the SQL @IS NOT DISTINCT FROM@ operator, and will equate
43-- This corresponds to the SQL @IS NOT DISTINCT FROM@ operator, and will equate
72-- @null@ values as @true@. This differs from @=@ which would return @null@.
44-- @null@ values as @true@. This differs from @=@ which would return @null@.
73-- This operator matches Haskell's '==' operator. For an operator identical to
45-- This operator matches Haskell's '==' operator. For an operator identical to
74-- SQL @=@, see '==?'.
46-- SQL @=@, see '==?'.
75−(==.) :: Sql DBEq a => Expr a -> Expr a -> Expr Bool
47+(==.) :: forall a. Sql DBEq a => Expr a -> Expr a -> Expr Bool
76−(==.) = seq nullabilization
48+(==.) = case nullable @a of
49+ Null -> \ma mb -> isNull ma &&. isNull mb ||. ma ==? mb
50+ NotNull -> eq
77infix 4 ==.
51infix 4 ==.
52+{-# INLINABLE (==.) #-}
78
53
79
54
80-- | Test if two expressions are different (not equal).
55-- | Test if two expressions are different (not equal).
@@ -83,9 +58,12 @@ infix 4 ==.
83-- @false@ when comparing two @null@ values. This differs from ordinary @=@
58-- @false@ when comparing two @null@ values. This differs from ordinary @=@
84-- which would return @null@. This operator is closer to Haskell's '=='
59-- which would return @null@. This operator is closer to Haskell's '=='
85-- operator. For an operator identical to SQL @=@, see '/=?'.
60-- operator. For an operator identical to SQL @=@, see '/=?'.
86−(/=.) :: Sql DBEq a => Expr a -> Expr a -> Expr Bool
61+(/=.) :: forall a. Sql DBEq a => Expr a -> Expr a -> Expr Bool
87−(/=.) = sne nullabilization
62+(/=.) = case nullable @a of
63+ Null -> \ma mb -> isNull ma `ne` isNull mb ||. ma /=? mb
64+ NotNull -> ne
88infix 4 /=.
65infix 4 /=.
66+{-# INLINABLE (/=.) #-}
89
67
90
68
91-- | Test if two expressions are equal. This operator is usually the best
69-- | Test if two expressions are equal. This operator is usually the best
@@ -94,14 +72,8 @@ infix 4 /=.
94--
72--
95-- This corresponds to the SQL @=@ operator, though it will always return a
73-- This corresponds to the SQL @=@ operator, though it will always return a
96-- 'Bool'.
74-- 'Bool'.
97−--
98−-- >>> select c $ pure $ lit Nothing ==? lit True
99−-- False
100−--
101−-- >>> select c $ pure $ lit Nothing ==? lit Nothing
102−-- False
103(==?) :: DBEq a => Expr (Maybe a) -> Expr (Maybe a) -> Expr Bool
75(==?) :: DBEq a => Expr (Maybe a) -> Expr (Maybe a) -> Expr Bool
104−a ==? b = coalesce $ unsafeLiftOpNullable eq a b
76+a ==? b = coalesce $ unsafeLiftOpNull eq a b
105infix 4 ==?
77infix 4 ==?
106
78
107
79
@@ -109,24 +81,21 @@ infix 4 ==?
109--
81--
110-- This corresponds to the SQL @<>@ operator, though it will always return a
82-- This corresponds to the SQL @<>@ operator, though it will always return a
111-- 'Bool'.
83-- 'Bool'.
112−--
113−-- >>> select c $ pure $ lit Nothing /=? lit True
114−-- True
115−--
116−-- >>> select c $ pure $ lit Nothing /=? lit Nothing
117−-- False
118(/=?) :: DBEq a => Expr (Maybe a) -> Expr (Maybe a) -> Expr Bool
84(/=?) :: DBEq a => Expr (Maybe a) -> Expr (Maybe a) -> Expr Bool
119−a /=? b = coalesce $ unsafeLiftOpNullable ne a b
85+a /=? b = coalesce $ unsafeLiftOpNull ne a b
120infix 4 /=?
86infix 4 /=?
121
87
122
88
123-- | Like the SQL @IN@ operator, but implemented by folding over a list with
89-- | Like the SQL @IN@ operator, but implemented by folding over a list with
124-- '==.' and '||.'.
90-- '==.' and '||.'.
125−--
91+in_ :: forall a f. (Sql DBEq a, Foldable f)
126−-- >>> select c $ return $ lit (5 :: Int32) `in_` [ lit x | x <- [1..5] ]
127−-- [True]
128−--
129−-- >>> select c $ return $ lit (42 :: Int32) `in_` [ lit x | x <- [1..5] ]
130−-- [False]
131−in_ :: (Sql DBEq a, Foldable f) => f (Expr a) -> Expr a -> Expr Bool
92+ => Expr a -> f (Expr a) -> Expr Bool
132−in_ = sin nullabilization
93+in_ a (toList -> as) = case nullable @a of
94+ Null -> or_ $ map (a ==.) as
95+ NotNull -> case nonEmpty as of
96+ Nothing -> false
97+ Just xs ->
98+ fromPrimExpr $
99+ Opaleye.BinExpr Opaleye.OpIn
100+ (toPrimExpr a)
101+ (Opaleye.ListExpr (toPrimExpr <$> xs))
src/Rel8/Expr/Function.hs+2−33
@@ -20,12 +20,12 @@ import Prelude
20import qualified Opaleye.Internal.HaskellDB.PrimQuery as Opaleye
20import qualified Opaleye.Internal.HaskellDB.PrimQuery as Opaleye
21
21
22-- rel8
22-- rel8
23−import Rel8.Expr ( Expr( Expr ) )
23+import {-# SOURCE #-} Rel8.Expr ( Expr( Expr ) )
24import Rel8.Expr.Opaleye
24import Rel8.Expr.Opaleye
25 ( castExpr
25 ( castExpr
26 , fromPrimExpr, toPrimExpr, zipPrimExprsWith
26 , fromPrimExpr, toPrimExpr, zipPrimExprsWith
27 )
27 )
28−import Rel8.Schema.Nullability ( Sql )
28+import Rel8.Schema.Null ( Sql )
29import Rel8.Type ( DBType )
29import Rel8.Type ( DBType )
30
30
31
31
@@ -47,42 +47,11 @@ instance (arg ~ Expr a, Function args res) => Function arg (args -> res) where
47
47
48-- | Construct an n-ary function that produces an 'Expr' that when called runs
48-- | Construct an n-ary function that produces an 'Expr' that when called runs
49-- a SQL function.
49-- a SQL function.
50−--
51−-- For example, here's how we can wrap PostgreSQL's @factorial@ function:
52−--
53−-- >>> :{
54−-- factorial :: Expr Int64 -> Expr Data.Scientific.Scientific
55−-- factorial = function "factorial"
56−-- :}
57−--
58−-- >>> select c $ pure $ factorial 5
59−-- [120.0]
60−--
61−-- The same approach works for any number of arguments:
62−--
63−-- >>> :{
64−-- power :: Expr Float -> Expr Float -> Expr Double
65−-- power = function "power"
66−-- :}
67−--
68−-- >>> select c $ pure $ power 9 3
69−-- [729.0]
70function :: Function args result => String -> args -> result
50function :: Function args result => String -> args -> result
71function = applyArgument . Opaleye.FunExpr
51function = applyArgument . Opaleye.FunExpr
72
52
73
53
74-- | Construct a function call for functions with no arguments.
54-- | Construct a function call for functions with no arguments.
75−--
76−-- For example, we can call the database function @pi()@ by using
77−-- @nullaryFunction@:
78−--
79−-- >>> :{
80−-- sqlPi :: Expr Double
81−-- sqlPi = nullaryFunction "pi"
82−-- :}
83−--
84−-- >>> select c $ pure $ sqlPi
85−-- [3.141592653589793]
86nullaryFunction :: Sql DBType a => String -> Expr a
55nullaryFunction :: Sql DBType a => String -> Expr a
87nullaryFunction name = castExpr $ Expr (Opaleye.FunExpr name [])
56nullaryFunction name = castExpr $ Expr (Opaleye.FunExpr name [])
88
57
src/Rel8/Expr/Null.hs+26−39
@@ -5,11 +5,11 @@
5{-# options -fno-warn-redundant-constraints #-}
5{-# options -fno-warn-redundant-constraints #-}
6
6
7module Rel8.Expr.Null
7module Rel8.Expr.Null
8− ( null, snull, nullable, nullableOf
8+ ( null, snull, nullableExpr, nullableOf
9 , isNull, isNonNull
9 , isNull, isNonNull
10 , nullify, unsafeUnnullify
10 , nullify, unsafeUnnullify
11− , mapNullable, liftOpNullable
11+ , mapNull, liftOpNull
12− , unsafeMapNullable, unsafeLiftOpNullable
12+ , unsafeMapNull, unsafeLiftOpNull
13 )
13 )
14where
14where
15
15
@@ -23,7 +23,7 @@ import qualified Opaleye.Internal.HaskellDB.PrimQuery as Opaleye
23import {-# SOURCE #-} Rel8.Expr ( Expr( Expr ) )
23import {-# SOURCE #-} Rel8.Expr ( Expr( Expr ) )
24import Rel8.Expr.Bool ( (||.), boolExpr )
24import Rel8.Expr.Bool ( (||.), boolExpr )
25import Rel8.Expr.Opaleye ( scastExpr, mapPrimExpr )
25import Rel8.Expr.Opaleye ( scastExpr, mapPrimExpr )
26−import Rel8.Schema.Nullability ( Nullability( Nullable ), IsMaybe )
26+import Rel8.Schema.Null ( NotNull )
27import Rel8.Type ( DBType, typeInformation )
27import Rel8.Type ( DBType, typeInformation )
28import Rel8.Type.Information ( TypeInformation )
28import Rel8.Type.Information ( TypeInformation )
29
29
@@ -31,7 +31,7 @@ import Rel8.Type.Information ( TypeInformation )
31-- | Lift an expression that can't be @null@ to a type that might be @null@.
31-- | Lift an expression that can't be @null@ to a type that might be @null@.
32-- This is an identity operation in terms of any generated query, and just
32-- This is an identity operation in terms of any generated query, and just
33-- modifies the query's type.
33-- modifies the query's type.
34−nullify :: IsMaybe a ~ 'False => Expr a -> Expr (Maybe a)
34+nullify :: NotNull a => Expr a -> Expr (Maybe a)
35nullify (Expr a) = Expr a
35nullify (Expr a) = Expr a
36
36
37
37
@@ -40,76 +40,63 @@ unsafeUnnullify (Expr a) = Expr a
40
40
41
41
42-- | Like 'maybe', but to eliminate @null@.
42-- | Like 'maybe', but to eliminate @null@.
43−--
44−-- >>> select c $ pure $ null 0 id (nullExpr :: Expr (Maybe Int32))
45−-- [0]
46−--
47−-- >>> select c $ pure $ null 0 id (lit (Just 42) :: Expr (Maybe Int32))
48−-- [42]
49−nullable :: Expr b -> (Expr a -> Expr b) -> Expr (Maybe a) -> Expr b
43+nullableExpr :: Expr b -> (Expr a -> Expr b) -> Expr (Maybe a) -> Expr b
50−nullable b f ma = boolExpr (f (unsafeUnnullify ma)) b (isNull ma)
44+nullableExpr b f ma = boolExpr (f (unsafeUnnullify ma)) b (isNull ma)
51
45
52
46
53−nullableOf :: (IsMaybe a ~ 'False, DBType a)
54− => Maybe (Expr a) -> Expr (Maybe a)
47+nullableOf :: DBType a => Maybe (Expr a) -> Expr (Maybe a)
55nullableOf = maybe null nullify
48nullableOf = maybe null nullify
56
49
57
50
58−-- | Like 'isNothing', but for @null@.
51+-- | Like 'Data.Maybe.isNothing', but for @null@.
59−--
60−-- >>> select c $ pure $ isNull (nullExpr :: Expr (Maybe Int32))
61−-- [True]
62−--
63−-- >>> select c $ pure $ isNull (lit (Just 42) :: Expr (Maybe Int32))
64−-- [False]
65isNull :: Expr (Maybe a) -> Expr Bool
52isNull :: Expr (Maybe a) -> Expr Bool
66isNull = mapPrimExpr (Opaleye.UnExpr Opaleye.OpIsNull)
53isNull = mapPrimExpr (Opaleye.UnExpr Opaleye.OpIsNull)
67
54
68
55
69−-- | Like 'isJust', but for @null@.
56+-- | Like 'Data.Maybe.isJust', but for @null@.
70isNonNull :: Expr (Maybe a) -> Expr Bool
57isNonNull :: Expr (Maybe a) -> Expr Bool
71isNonNull = mapPrimExpr (Opaleye.UnExpr Opaleye.OpIsNotNull)
58isNonNull = mapPrimExpr (Opaleye.UnExpr Opaleye.OpIsNotNull)
72
59
73
60
74-- | Lift an operation on non-@null@ values to an operation on possibly @null@
61-- | Lift an operation on non-@null@ values to an operation on possibly @null@
75−-- values. When given @null@, @mapNullable f@ returns @null@.
62+-- values. When given @null@, @mapNull f@ returns @null@.
76--
63--
77-- This is like 'fmap' for 'Maybe'.
64-- This is like 'fmap' for 'Maybe'.
78−mapNullable :: (IsMaybe b ~ 'False, DBType b)
65+mapNull :: DBType b
79 => (Expr a -> Expr b) -> Expr (Maybe a) -> Expr (Maybe b)
66 => (Expr a -> Expr b) -> Expr (Maybe a) -> Expr (Maybe b)
80−mapNullable f ma = boolExpr (unsafeMapNullable f ma) null (isNull ma)
67+mapNull f ma = boolExpr (unsafeMapNull f ma) null (isNull ma)
81
68
82
69
83-- | Lift a binary operation on non-@null@ expressions to an equivalent binary
70-- | Lift a binary operation on non-@null@ expressions to an equivalent binary
84-- operator on possibly @null@ expressions. If either of the final arguments
71-- operator on possibly @null@ expressions. If either of the final arguments
85−-- are @null@, @liftOpNullable@ returns @null@.
72+-- are @null@, @liftOpNull@ returns @null@.
86--
73--
87-- This is like 'liftA2' for 'Maybe'.
74-- This is like 'liftA2' for 'Maybe'.
88−liftOpNullable :: (IsMaybe c ~ 'False, DBType c)
75+liftOpNull :: DBType c
89 => (Expr a -> Expr b -> Expr c)
76 => (Expr a -> Expr b -> Expr c)
90 -> Expr (Maybe a) -> Expr (Maybe b) -> Expr (Maybe c)
77 -> Expr (Maybe a) -> Expr (Maybe b) -> Expr (Maybe c)
91−liftOpNullable f ma mb =
78+liftOpNull f ma mb =
92− boolExpr (unsafeLiftOpNullable f ma mb) null
79+ boolExpr (unsafeLiftOpNull f ma mb) null
93 (isNull ma ||. isNull mb)
80 (isNull ma ||. isNull mb)
81+{-# INLINABLE liftOpNull #-}
94
82
95
83
96−snull :: Nullability a (Maybe a) -> TypeInformation a -> Expr (Maybe a)
84+snull :: TypeInformation a -> Expr (Maybe a)
97−snull nullability info =
98− scastExpr nullability info $ Expr $ Opaleye.ConstExpr Opaleye.NullLit
85+snull info = scastExpr info $ Expr $ Opaleye.ConstExpr Opaleye.NullLit
99
86
100
87
101-- | Corresponds to SQL @null@.
88-- | Corresponds to SQL @null@.
102−null :: (IsMaybe a ~ 'False, DBType a) => Expr (Maybe a)
89+null :: DBType a => Expr (Maybe a)
103−null = snull Nullable typeInformation
90+null = snull typeInformation
104
91
105
92
106−unsafeMapNullable :: IsMaybe b ~ 'False
93+unsafeMapNull :: NotNull b
107 => (Expr a -> Expr b) -> Expr (Maybe a) -> Expr (Maybe b)
94 => (Expr a -> Expr b) -> Expr (Maybe a) -> Expr (Maybe b)
108−unsafeMapNullable f ma = nullify (f (unsafeUnnullify ma))
95+unsafeMapNull f ma = nullify (f (unsafeUnnullify ma))
109
96
110
97
111−unsafeLiftOpNullable :: IsMaybe c ~ 'False
98+unsafeLiftOpNull :: NotNull c
112 => (Expr a -> Expr b -> Expr c)
99 => (Expr a -> Expr b -> Expr c)
113 -> Expr (Maybe a) -> Expr (Maybe b) -> Expr (Maybe c)
100 -> Expr (Maybe a) -> Expr (Maybe b) -> Expr (Maybe c)
114−unsafeLiftOpNullable f ma mb =
101+unsafeLiftOpNull f ma mb =
115 nullify (f (unsafeUnnullify ma) (unsafeUnnullify mb))
102 nullify (f (unsafeUnnullify ma) (unsafeUnnullify mb))
src/Rel8/Expr/Num.hs+68−15
@@ -4,54 +4,107 @@
4{-# options_ghc -fno-warn-redundant-constraints #-}
4{-# options_ghc -fno-warn-redundant-constraints #-}
5
5
6module Rel8.Expr.Num
6module Rel8.Expr.Num
7+ ( fromIntegral
8+ , realToFrac
9+ , div, mod, divMod
10+ , quot, rem, quotRem
7− ( fromIntegral, realToFrac, div, mod, ceiling, floor, round, truncate
11+ , ceiling, floor, round, truncate
8 )
12 )
9where
13where
10
14
11-- base
15-- base
12−import Prelude ()
16+import Prelude ( (+), (-), fst, negate, signum, snd )
13
17
14-- rel
18-- rel
15import Rel8.Expr ( Expr( Expr ) )
19import Rel8.Expr ( Expr( Expr ) )
20+import Rel8.Expr.Eq ( (==.) )
16import Rel8.Expr.Function ( function )
21import Rel8.Expr.Function ( function )
17import Rel8.Expr.Opaleye ( castExpr )
22import Rel8.Expr.Opaleye ( castExpr )
18−import Rel8.Schema.Nullability ( IsMaybe, Sql )
23+import Rel8.Schema.Null ( Homonullable, Sql )
24+import Rel8.Table.Bool ( bool )
19import Rel8.Type.Num ( DBFractional, DBIntegral, DBNum )
25import Rel8.Type.Num ( DBFractional, DBIntegral, DBNum )
20
26
21
27
28+-- | Cast 'DBIntegral' types to 'DBNum' types. For example, this can be useful
29+-- if you need to turn an @Expr Int32@ into an @Expr Double@.
22−fromIntegral :: (Sql DBIntegral a, Sql DBNum b, IsMaybe a ~ IsMaybe b)
30+fromIntegral :: (Sql DBIntegral a, Sql DBNum b, Homonullable a b)
23 => Expr a -> Expr b
31 => Expr a -> Expr b
24fromIntegral (Expr a) = castExpr (Expr a)
32fromIntegral (Expr a) = castExpr (Expr a)
25
33
26
34
35+-- | Cast 'DBNum' types to 'DBFractional' types. For example, his can be useful
36+-- to convert @Expr Float@ to @Expr Double@.
27−realToFrac :: (Sql DBNum a, Sql DBFractional b, IsMaybe a ~ IsMaybe b)
37+realToFrac :: (Sql DBNum a, Sql DBFractional b, Homonullable a b)
28 => Expr a -> Expr b
38 => Expr a -> Expr b
29realToFrac (Expr a) = castExpr (Expr a)
39realToFrac (Expr a) = castExpr (Expr a)
30
40
31
41
42+-- | Round a 'DBFractional' to a 'DBIntegral' by rounding to the nearest larger
43+-- integer.
44+--
45+-- Corresponds to the @ceiling()@ function.
32−ceiling :: (Sql DBFractional a, Sql DBIntegral b, IsMaybe a ~ IsMaybe b)
46+ceiling :: (Sql DBFractional a, Sql DBIntegral b, Homonullable a b)
33 => Expr a -> Expr b
47 => Expr a -> Expr b
34−ceiling = function "CEILING"
48+ceiling = function "ceiling"
35
49
36
50
51+-- | Emulates the behaviour of the Haskell function 'Prelude.div' in
52+-- PostgreSQL.
37div :: Sql DBIntegral a => Expr a -> Expr a -> Expr a
53div :: Sql DBIntegral a => Expr a -> Expr a -> Expr a
38−div = function "DIV"
54+div n d = fst (divMod n d)
39
55
40
56
57+-- | Emulates the behaviour of the Haskell function 'Prelude.mod' in
58+-- PostgreSQL.
41mod :: Sql DBIntegral a => Expr a -> Expr a -> Expr a
59mod :: Sql DBIntegral a => Expr a -> Expr a -> Expr a
42−mod = function "MOD"
60+mod n d = snd (divMod n d)
43
61
44
62
63+-- | Simultaneous 'div' and 'mod'.
64+divMod :: Sql DBIntegral a => Expr a -> Expr a -> (Expr a, Expr a)
65+divMod n d = bool qr (q - 1, r + d) (signum r ==. negate (signum d))
66+ where
67+ qr@(q, r) = quotRem n d
68+
69+
70+-- | Perform integral division. Corresponds to the @div()@ function in
71+-- PostgreSQL, which behaves like Haskell's 'Prelude.quot' rather than
72+-- 'Prelude.div'.
73+quot :: Sql DBIntegral a => Expr a -> Expr a -> Expr a
74+quot = function "div"
75+
76+
77+-- | Corresponds to the @mod()@ function in PostgreSQL, which behaves like
78+-- Haskell's 'Prelude.rem' rather than 'Prelude.mod'.
79+rem :: Sql DBIntegral a => Expr a -> Expr a -> Expr a
80+rem = function "mod"
81+
82+
83+-- | Simultaneous 'quot' and 'rem'.
84+quotRem :: Sql DBIntegral a => Expr a -> Expr a -> (Expr a, Expr a)
85+quotRem n d = (quot n d, rem n d)
86+
87+
88+-- | Round a 'DFractional' to a 'DBIntegral' by rounding to the nearest smaller
89+-- integer.
90+--
91+-- Corresponds to the @floor()@ function.
45−floor :: (Sql DBFractional a, Sql DBIntegral b, IsMaybe a ~ IsMaybe b)
92+floor :: (Sql DBFractional a, Sql DBIntegral b, Homonullable a b)
46 => Expr a -> Expr b
93 => Expr a -> Expr b
47−floor = function "FLOOR"
94+floor = function "floor"
48
95
49
96
97+-- | Round a 'DBFractional' to a 'DBIntegral' by rounding to the nearest
98+-- integer.
99+--
100+-- Corresponds to the @round()@ function.
50−round :: (Sql DBFractional a, Sql DBIntegral b, IsMaybe a ~ IsMaybe b)
101+round :: (Sql DBFractional a, Sql DBIntegral b, Homonullable a b)
51 => Expr a -> Expr b
102 => Expr a -> Expr b
52−round = function "ROUND"
103+round = function "round"
53
104
54
105
106+-- | Round a 'DBFractional' to a 'DBIntegral' by rounding to the nearest
107+-- integer towards zero.
55−truncate :: (Sql DBFractional a, Sql DBIntegral b, IsMaybe a ~ IsMaybe b)
108+truncate :: (Sql DBFractional a, Sql DBIntegral b, Homonullable a b)
56 => Expr a -> Expr b
109 => Expr a -> Expr b
57−truncate = function "TRUNC"
110+truncate = function "trunc"
src/Rel8/Expr/Opaleye.hs+27−13
@@ -1,8 +1,6 @@
1{-# language FlexibleContexts #-}
1{-# language FlexibleContexts #-}
2−{-# language LambdaCase #-}
3{-# language NamedFieldPuns #-}
2{-# language NamedFieldPuns #-}
4{-# language ScopedTypeVariables #-}
3{-# language ScopedTypeVariables #-}
5−{-# language TypeApplications #-}
6{-# language TypeFamilies #-}
4{-# language TypeFamilies #-}
7
5
8{-# options_ghc -fno-warn-redundant-constraints #-}
6{-# options_ghc -fno-warn-redundant-constraints #-}
@@ -12,7 +10,7 @@ module Rel8.Expr.Opaleye
12 , scastExpr, sunsafeCastExpr
10 , scastExpr, sunsafeCastExpr
13 , unsafeLiteral
11 , unsafeLiteral
14 , fromPrimExpr, toPrimExpr, mapPrimExpr, zipPrimExprsWith, traversePrimExpr
12 , fromPrimExpr, toPrimExpr, mapPrimExpr, zipPrimExprsWith, traversePrimExpr
15− , toColumn, fromColumn
13+ , toColumn, fromColumn, traverseFieldP
16 )
14 )
17where
15where
18
16
@@ -25,31 +23,41 @@ import qualified Opaleye.Internal.HaskellDB.PrimQuery as Opaleye
25
23
26-- rel8
24-- rel8
27import {-# SOURCE #-} Rel8.Expr ( Expr( Expr ) )
25import {-# SOURCE #-} Rel8.Expr ( Expr( Expr ) )
28−import Rel8.Schema.Nullability ( Nullability, Sql, nullabilization )
26+import Rel8.Schema.Null ( Unnullify, Sql )
29import Rel8.Type ( DBType, typeInformation )
27import Rel8.Type ( DBType, typeInformation )
30import Rel8.Type.Information ( TypeInformation(..) )
28import Rel8.Type.Information ( TypeInformation(..) )
31
29
30+-- profunctors
31+import Data.Profunctor ( Profunctor, dimap )
32+
32
33
33castExpr :: Sql DBType a => Expr a -> Expr a
34castExpr :: Sql DBType a => Expr a -> Expr a
34−castExpr = scastExpr nullabilization typeInformation
35+castExpr = scastExpr typeInformation
35
36
36
37
38+-- | Cast an expression to a different type. Corresponds to a @CAST()@ function
39+-- call.
37unsafeCastExpr :: Sql DBType b => Expr a -> Expr b
40unsafeCastExpr :: Sql DBType b => Expr a -> Expr b
38−unsafeCastExpr = sunsafeCastExpr nullabilization typeInformation
41+unsafeCastExpr = sunsafeCastExpr typeInformation
39
42
40
43
41−scastExpr :: Nullability db a -> TypeInformation db -> Expr a -> Expr a
44+scastExpr :: TypeInformation (Unnullify a) -> Expr a -> Expr a
42scastExpr = sunsafeCastExpr
45scastExpr = sunsafeCastExpr
43
46
44
47
45sunsafeCastExpr :: ()
48sunsafeCastExpr :: ()
46− => Nullability db b -> TypeInformation db -> Expr a -> Expr b
49+ => TypeInformation (Unnullify b) -> Expr a -> Expr b
47−sunsafeCastExpr _ TypeInformation {typeName} =
50+sunsafeCastExpr TypeInformation {typeName} =
48 fromPrimExpr . Opaleye.CastExpr typeName . toPrimExpr
51 fromPrimExpr . Opaleye.CastExpr typeName . toPrimExpr
49
52
50
53
54+-- | Unsafely construct an expression from literal SQL.
55+--
56+-- This is an escape hatch, and can be used if Rel8 can not adequately express
57+-- the query you need. If you find yourself using this function, please let us
58+-- know, as it may indicate that something is missing from Rel8!
51−unsafeLiteral :: Sql DBType a => String -> Expr a
59+unsafeLiteral :: String -> Expr a
52−unsafeLiteral = castExpr . Expr . Opaleye.ConstExpr . Opaleye.OtherLit
60+unsafeLiteral = Expr . Opaleye.ConstExpr . Opaleye.OtherLit
53
61
54
62
55fromPrimExpr :: Opaleye.PrimExpr -> Expr a
63fromPrimExpr :: Opaleye.PrimExpr -> Expr a
@@ -75,9 +83,15 @@ traversePrimExpr :: Functor f
75traversePrimExpr f = fmap fromPrimExpr . f . toPrimExpr
83traversePrimExpr f = fmap fromPrimExpr . f . toPrimExpr
76
84
77
85
86+traverseFieldP :: Profunctor p
87+ => p (Opaleye.Field_ n x) (Opaleye.Field_ m y)
88+ -> p (Expr a) (Expr b)
89+traverseFieldP = dimap (toColumn . toPrimExpr) (fromPrimExpr . fromColumn)
90+
91+
78−toColumn :: Opaleye.PrimExpr -> Opaleye.Column b
92+toColumn :: Opaleye.PrimExpr -> Opaleye.Field_ n b
79toColumn = Opaleye.Column
93toColumn = Opaleye.Column
80
94
81
95
82−fromColumn :: Opaleye.Column b -> Opaleye.PrimExpr
96+fromColumn :: Opaleye.Field_ n b -> Opaleye.PrimExpr
83fromColumn (Opaleye.Column a) = a
97fromColumn (Opaleye.Column a) = a
src/Rel8/Expr/Ord.hs+33−53
@@ -1,6 +1,5 @@
1{-# language DataKinds #-}
1{-# language DataKinds #-}
2{-# language FlexibleContexts #-}
2{-# language FlexibleContexts #-}
3−{-# language LambdaCase #-}
4{-# language GADTs #-}
3{-# language GADTs #-}
5{-# language ScopedTypeVariables #-}
4{-# language ScopedTypeVariables #-}
6{-# language TypeApplications #-}
5{-# language TypeApplications #-}
@@ -8,8 +7,7 @@
8{-# options_ghc -fno-warn-redundant-constraints #-}
7{-# options_ghc -fno-warn-redundant-constraints #-}
9
8
10module Rel8.Expr.Ord
9module Rel8.Expr.Ord
11− ( slt, sle, sgt, sge
12− , (<.), (<=.), (>.), (>=.)
10+ ( (<.), (<=.), (>.), (>=.)
13 , (<?), (<=?), (>?), (>=?)
11 , (<?), (<=?), (>?), (>=?)
14 , leastExpr, greatestExpr
12 , leastExpr, greatestExpr
15 )
13 )
@@ -24,12 +22,9 @@ import qualified Opaleye.Internal.HaskellDB.PrimQuery as Opaleye
24-- rel8
22-- rel8
25import Rel8.Expr ( Expr( Expr ) )
23import Rel8.Expr ( Expr( Expr ) )
26import Rel8.Expr.Bool ( (&&.), (||.), coalesce )
24import Rel8.Expr.Bool ( (&&.), (||.), coalesce )
27−import Rel8.Expr.Null ( isNull, isNonNull, nullable, unsafeLiftOpNullable )
25+import Rel8.Expr.Null ( isNull, isNonNull, nullableExpr, unsafeLiftOpNull )
28−import Rel8.Expr.Opaleye ( zipPrimExprsWith )
26+import Rel8.Expr.Opaleye ( toPrimExpr, zipPrimExprsWith )
29−import Rel8.Schema.Nullability
27+import Rel8.Schema.Null ( Nullity( Null, NotNull ), Sql, nullable )
30− ( Nullability( NonNullable, Nullable )
31− , Sql, nullabilization
32− )
33import Rel8.Type.Ord ( DBOrd )
28import Rel8.Type.Ord ( DBOrd )
34
29
35
30
@@ -49,87 +44,71 @@ ge :: DBOrd a => Expr a -> Expr a -> Expr Bool
49ge = zipPrimExprsWith (Opaleye.BinExpr (Opaleye.:>=))
44ge = zipPrimExprsWith (Opaleye.BinExpr (Opaleye.:>=))
50
45
51
46
52−slt :: DBOrd db => Nullability db a -> Expr a -> Expr a -> Expr Bool
53−slt = \case
54− Nullable -> \ma mb -> isNull ma &&. isNonNull mb ||. ma <? mb
55− NonNullable -> lt
56−
57−
58−sle :: DBOrd db => Nullability db a -> Expr a -> Expr a -> Expr Bool
59−sle = \case
60− Nullable -> \ma mb -> isNull ma ||. ma <=? mb
61− NonNullable -> le
62−
63−
64−sgt :: DBOrd db => Nullability db a -> Expr a -> Expr a -> Expr Bool
65−sgt = \case
66− Nullable -> \ma mb -> isNonNull ma &&. isNull mb ||. ma >? mb
67− NonNullable -> gt
68−
69−
70−sge :: DBOrd db => Nullability db a -> Expr a -> Expr a -> Expr Bool
71−sge = \case
72− Nullable -> \ma mb -> isNull mb ||. ma >=? mb
73− NonNullable -> ge
74−
75−
76-- | Corresponds to the SQL @<@ operator. Note that this differs from SQL @<@
47-- | Corresponds to the SQL @<@ operator. Note that this differs from SQL @<@
77-- as @null@ will sort below any other value. For a version of @<@ that exactly
48-- as @null@ will sort below any other value. For a version of @<@ that exactly
78-- matches SQL, see '(<?)'.
49-- matches SQL, see '(<?)'.
79−(<.) :: Sql DBOrd a => Expr a -> Expr a -> Expr Bool
50+(<.) :: forall a. Sql DBOrd a => Expr a -> Expr a -> Expr Bool
80−(<.) = slt nullabilization
51+(<.) = case nullable @a of
52+ Null -> \ma mb -> isNull ma &&. isNonNull mb ||. ma <? mb
53+ NotNull -> lt
81infix 4 <.
54infix 4 <.
82
55
83
56
84-- | Corresponds to the SQL @<=@ operator. Note that this differs from SQL @<=@
57-- | Corresponds to the SQL @<=@ operator. Note that this differs from SQL @<=@
85-- as @null@ will sort below any other value. For a version of @<=@ that exactly
58-- as @null@ will sort below any other value. For a version of @<=@ that exactly
86-- matches SQL, see '(<=?)'.
59-- matches SQL, see '(<=?)'.
87−(<=.) :: Sql DBOrd a => Expr a -> Expr a -> Expr Bool
60+(<=.) :: forall a. Sql DBOrd a => Expr a -> Expr a -> Expr Bool
88−(<=.) = sle nullabilization
61+(<=.) = case nullable @a of
62+ Null -> \ma mb -> isNull ma ||. ma <=? mb
63+ NotNull -> le
89infix 4 <=.
64infix 4 <=.
90
65
91
66
92-- | Corresponds to the SQL @>@ operator. Note that this differs from SQL @>@
67-- | Corresponds to the SQL @>@ operator. Note that this differs from SQL @>@
93-- as @null@ will sort below any other value. For a version of @>@ that exactly
68-- as @null@ will sort below any other value. For a version of @>@ that exactly
94-- matches SQL, see '(>?)'.
69-- matches SQL, see '(>?)'.
95−(>.) :: Sql DBOrd a => Expr a -> Expr a -> Expr Bool
70+(>.) :: forall a. Sql DBOrd a => Expr a -> Expr a -> Expr Bool
96−(>.) = sgt nullabilization
71+(>.) = case nullable @a of
72+ Null -> \ma mb -> isNonNull ma &&. isNull mb ||. ma >? mb
73+ NotNull -> gt
97infix 4 >.
74infix 4 >.
98
75
99
76
100-- | Corresponds to the SQL @>=@ operator. Note that this differs from SQL @>@
77-- | Corresponds to the SQL @>=@ operator. Note that this differs from SQL @>@
101-- as @null@ will sort below any other value. For a version of @>=@ that
78-- as @null@ will sort below any other value. For a version of @>=@ that
102-- exactly matches SQL, see '(>=?)'.
79-- exactly matches SQL, see '(>=?)'.
103−(>=.) :: Sql DBOrd a => Expr a -> Expr a -> Expr Bool
80+(>=.) :: forall a. Sql DBOrd a => Expr a -> Expr a -> Expr Bool
104−(>=.) = sge nullabilization
81+(>=.) = case nullable @a of
82+ Null -> \ma mb -> isNull mb ||. ma >=? mb
83+ NotNull -> ge
105infix 4 >=.
84infix 4 >=.
106
85
107
86
108-- | Corresponds to the SQL @<@ operator. Returns @null@ if either arguments
87-- | Corresponds to the SQL @<@ operator. Returns @null@ if either arguments
109-- are @null@.
88-- are @null@.
110(<?) :: DBOrd a => Expr (Maybe a) -> Expr (Maybe a) -> Expr Bool
89(<?) :: DBOrd a => Expr (Maybe a) -> Expr (Maybe a) -> Expr Bool
111−a <? b = coalesce $ unsafeLiftOpNullable lt a b
90+a <? b = coalesce $ unsafeLiftOpNull lt a b
112infix 4 <?
91infix 4 <?
113
92
114
93
115-- | Corresponds to the SQL @<=@ operator. Returns @null@ if either arguments
94-- | Corresponds to the SQL @<=@ operator. Returns @null@ if either arguments
116-- are @null@.
95-- are @null@.
117(<=?) :: DBOrd a => Expr (Maybe a) -> Expr (Maybe a) -> Expr Bool
96(<=?) :: DBOrd a => Expr (Maybe a) -> Expr (Maybe a) -> Expr Bool
118−a <=? b = coalesce $ unsafeLiftOpNullable le a b
97+a <=? b = coalesce $ unsafeLiftOpNull le a b
119infix 4 <=?
98infix 4 <=?
120
99
121
100
122-- | Corresponds to the SQL @>@ operator. Returns @null@ if either arguments
101-- | Corresponds to the SQL @>@ operator. Returns @null@ if either arguments
123-- are @null@.
102-- are @null@.
124(>?) :: DBOrd a => Expr (Maybe a) -> Expr (Maybe a) -> Expr Bool
103(>?) :: DBOrd a => Expr (Maybe a) -> Expr (Maybe a) -> Expr Bool
125−a >? b = coalesce $ unsafeLiftOpNullable gt a b
104+a >? b = coalesce $ unsafeLiftOpNull gt a b
126infix 4 >?
105infix 4 >?
127
106
128
107
129-- | Corresponds to the SQL @>=@ operator. Returns @null@ if either arguments
108-- | Corresponds to the SQL @>=@ operator. Returns @null@ if either arguments
130-- are @null@.
109-- are @null@.
131(>=?) :: DBOrd a => Expr (Maybe a) -> Expr (Maybe a) -> Expr Bool
110(>=?) :: DBOrd a => Expr (Maybe a) -> Expr (Maybe a) -> Expr Bool
132−a >=? b = coalesce $ unsafeLiftOpNullable ge a b
111+a >=? b = coalesce $ unsafeLiftOpNull ge a b
133infix 4 >=?
112infix 4 >=?
134
113
135
114
@@ -138,11 +117,11 @@ infix 4 >=?
138--
117--
139-- Corresponds to the SQL @least()@ function.
118-- Corresponds to the SQL @least()@ function.
140leastExpr :: forall a. Sql DBOrd a => Expr a -> Expr a -> Expr a
119leastExpr :: forall a. Sql DBOrd a => Expr a -> Expr a -> Expr a
141−leastExpr ma mb = case nullabilization @a of
120+leastExpr ma mb = case nullable @a of
142− Nullable -> nullable ma (\a -> nullable mb (least_ a) mb) ma
121+ Null -> nullableExpr ma (\a -> nullableExpr mb (least_ a) mb) ma
143− NonNullable -> least_ ma mb
122+ NotNull -> least_ ma mb
144 where
123 where
145− least_ (Expr a) (Expr b) = Expr (Opaleye.FunExpr "LEAST" [a, b])
124+ least_ a b = Expr (Opaleye.FunExpr "LEAST" [toPrimExpr a, toPrimExpr b])
146
125
147
126
148-- | Given two expressions, return the expression that sorts greater than the
127-- | Given two expressions, return the expression that sorts greater than the
@@ -150,8 +129,9 @@ leastExpr ma mb = case nullabilization @a of
150--
129--
151-- Corresponds to the SQL @greatest()@ function.
130-- Corresponds to the SQL @greatest()@ function.
152greatestExpr :: forall a. Sql DBOrd a => Expr a -> Expr a -> Expr a
131greatestExpr :: forall a. Sql DBOrd a => Expr a -> Expr a -> Expr a
153−greatestExpr ma mb = case nullabilization @a of
132+greatestExpr ma mb = case nullable @a of
154− Nullable -> nullable mb (\a -> nullable ma (greatest_ a) mb) ma
133+ Null -> nullableExpr mb (\a -> nullableExpr ma (greatest_ a) mb) ma
155− NonNullable -> greatest_ ma mb
134+ NotNull -> greatest_ ma mb
156 where
135 where
136+ greatest_ a b =
157− greatest_ (Expr a) (Expr b) = Expr (Opaleye.FunExpr "GREATEST" [a, b])
137+ Expr (Opaleye.FunExpr "GREATEST" [toPrimExpr a, toPrimExpr b])
src/Rel8/Expr/Order.hs−12
@@ -28,9 +28,6 @@ import Rel8.Type.Ord ( DBOrd )
28
28
29
29
30-- | Sort a column in ascending order.
30-- | Sort a column in ascending order.
31−--
32−-- >>> select c $ orderBy asc $ values [ lit x | x <- [1..5 :: Int32] ]
33−-- [1,2,3,4,5]
34asc :: DBOrd a => Order (Expr a)
31asc :: DBOrd a => Order (Expr a)
35asc = Order $ Opaleye.Order (\expr -> [(orderOp, toPrimExpr expr)])
32asc = Order $ Opaleye.Order (\expr -> [(orderOp, toPrimExpr expr)])
36 where
33 where
@@ -42,9 +39,6 @@ asc = Order $ Opaleye.Order (\expr -> [(orderOp, toPrimExpr expr)])
42
39
43
40
44-- | Sort a column in descending order.
41-- | Sort a column in descending order.
45−--
46−-- >>> select c $ orderBy desc $ values [ lit x | x <- [1..5 :: Int32] ]
47−-- [5,4,3,2,1]
48desc :: DBOrd a => Order (Expr a)
42desc :: DBOrd a => Order (Expr a)
49desc = Order $ Opaleye.Order (\expr -> [(orderOp, toPrimExpr expr)])
43desc = Order $ Opaleye.Order (\expr -> [(orderOp, toPrimExpr expr)])
50 where
44 where
@@ -57,9 +51,6 @@ desc = Order $ Opaleye.Order (\expr -> [(orderOp, toPrimExpr expr)])
57
51
58-- | Transform an ordering so that @null@ values appear first. This corresponds
52-- | Transform an ordering so that @null@ values appear first. This corresponds
59-- to @NULLS FIRST@ in SQL.
53-- to @NULLS FIRST@ in SQL.
60−--
61−-- >>> select c $ orderBy (nullsFirst desc) $ values $ [ nullExpr, nullExpr ] <> [ lit (Just x) | x <- [1..5 :: Int32] ]
62−-- [Nothing,Nothing,Just 5,Just 4,Just 3,Just 2,Just 1]
63nullsFirst :: Order (Expr a) -> Order (Expr (Maybe a))
54nullsFirst :: Order (Expr a) -> Order (Expr (Maybe a))
64nullsFirst (Order (Opaleye.Order f)) =
55nullsFirst (Order (Opaleye.Order f)) =
65 Order $ Opaleye.Order $ fmap (first g) . f . unsafeUnnullify
56 Order $ Opaleye.Order $ fmap (first g) . f . unsafeUnnullify
@@ -70,9 +61,6 @@ nullsFirst (Order (Opaleye.Order f)) =
70
61
71-- | Transform an ordering so that @null@ values appear first. This corresponds
62-- | Transform an ordering so that @null@ values appear first. This corresponds
72-- to @NULLS LAST@ in SQL.
63-- to @NULLS LAST@ in SQL.
73−--
74−-- >>> select c $ orderBy (nullsLast desc) $ values $ [ nullExpr, nullExpr ] <> [ lit (Just x) | x <- [1..5 :: Int32] ]
75−-- [Just 5,Just 4,Just 3,Just 2,Just 1,Nothing,Nothing]
76nullsLast :: Order (Expr a) -> Order (Expr (Maybe a))
64nullsLast :: Order (Expr a) -> Order (Expr (Maybe a))
77nullsLast (Order (Opaleye.Order f)) =
65nullsLast (Order (Opaleye.Order f)) =
78 Order $ Opaleye.Order $ fmap (first g) . f . unsafeUnnullify
66 Order $ Opaleye.Order $ fmap (first g) . f . unsafeUnnullify
src/Rel8/Expr/Sequence.hsnew file+22
@@ -0,0 +1,22 @@
1+module Rel8.Expr.Sequence
2+ ( nextval
3+ )
4+where
5+
6+-- base
7+import Data.Int ( Int64 )
8+import Prelude
9+
10+-- rel8
11+import Rel8.Expr ( Expr )
12+import Rel8.Expr.Function ( function )
13+import Rel8.Expr.Serialize ( litExpr )
14+import Rel8.Expr.Text ( quoteIdent )
15+
16+-- text
17+import Data.Text ( pack )
18+
19+
20+-- | See https://www.postgresql.org/docs/current/functions-sequence.html
21+nextval :: String -> Expr Int64
22+nextval = function "nextval" . quoteIdent . litExpr . pack
src/Rel8/Expr/Serialize.hs+16−15
@@ -21,28 +21,29 @@ import qualified Opaleye.Internal.HaskellDB.PrimQuery as Opaleye
21-- rel8
21-- rel8
22import {-# SOURCE #-} Rel8.Expr ( Expr( Expr ) )
22import {-# SOURCE #-} Rel8.Expr ( Expr( Expr ) )
23import Rel8.Expr.Opaleye ( scastExpr )
23import Rel8.Expr.Opaleye ( scastExpr )
24−import Rel8.Schema.Nullability
24+import Rel8.Schema.Null ( Unnullify, Nullity( Null, NotNull ), Sql, nullable )
25− ( Nullability( Nullable, NonNullable )
26− , Sql, nullabilization
27− )
28import Rel8.Type ( DBType, typeInformation )
25import Rel8.Type ( DBType, typeInformation )
29import Rel8.Type.Information ( TypeInformation(..) )
26import Rel8.Type.Information ( TypeInformation(..) )
30
27
31
28
29+-- | Produce an expression from a literal.
30+--
31+-- Note that you can usually use 'Rel8.lit', but @litExpr@ can solve problems
32+-- of inference in polymorphic code.
32litExpr :: Sql DBType a => a -> Expr a
33litExpr :: Sql DBType a => a -> Expr a
33−litExpr = slitExpr nullabilization typeInformation
34+litExpr = slitExpr nullable typeInformation
34
35
35
36
36−slitExpr :: Nullability db a -> TypeInformation db -> a -> Expr a
37+slitExpr :: Nullity a -> TypeInformation (Unnullify a) -> a -> Expr a
37−slitExpr nullable info@TypeInformation {encode} =
38+slitExpr nullity info@TypeInformation {encode} =
38− scastExpr nullable info . Expr . encoder
39+ scastExpr info . Expr . encoder
39 where
40 where
40− encoder = case nullable of
41+ encoder = case nullity of
41− Nullable -> maybe (Opaleye.ConstExpr Opaleye.NullLit) encode
42+ Null -> maybe (Opaleye.ConstExpr Opaleye.NullLit) encode
42− NonNullable -> encode
43+ NotNull -> encode
43
44
44
45
45−sparseValue :: Nullability db a -> TypeInformation db -> Hasql.Row a
46+sparseValue :: Nullity a -> TypeInformation (Unnullify a) -> Hasql.Row a
46−sparseValue nullability TypeInformation {decode, out} = case nullability of
47+sparseValue nullity TypeInformation {decode} = case nullity of
47− Nullable -> Hasql.column $ Hasql.nullable $ out <$> decode
48+ Null -> Hasql.column $ Hasql.nullable decode
48− NonNullable -> Hasql.column $ Hasql.nonNullable $ out <$> decode
49+ NotNull -> Hasql.column $ Hasql.nonNullable decode
src/Rel8/Expr/Text.hs+66−11
@@ -16,7 +16,10 @@ module Rel8.Expr.Text
16 , initcap, left, length, lengthEncoding, lpad, ltrim, md5
16 , initcap, left, length, lengthEncoding, lpad, ltrim, md5
17 , pgClientEncoding, quoteIdent, quoteLiteral, quoteNullable, regexpReplace
17 , pgClientEncoding, quoteIdent, quoteLiteral, quoteNullable, regexpReplace
18 , regexpSplitToArray, repeat, replace, reverse, right, rpad, rtrim
18 , regexpSplitToArray, repeat, replace, reverse, right, rpad, rtrim
19− , splitPart, strpos, substr, toAscii, toHex, translate
19+ , splitPart, strpos, substr, translate
20+
21+ -- * @LIKE@ and @ILIKE@
22+ , like, ilike
20 )
23 )
21where
24where
22
25
@@ -24,7 +27,7 @@ where
24import Data.Bool ( Bool )
27import Data.Bool ( Bool )
25import Data.Int ( Int32 )
28import Data.Int ( Int32 )
26import Data.Maybe ( Maybe( Nothing, Just ) )
29import Data.Maybe ( Maybe( Nothing, Just ) )
27−import Prelude ()
30+import Prelude ( flip )
28
31
29-- bytestring
32-- bytestring
30import Data.ByteString ( ByteString )
33import Data.ByteString ( ByteString )
@@ -32,7 +35,6 @@ import Data.ByteString ( ByteString )
32-- rel8
35-- rel8
33import Rel8.Expr ( Expr )
36import Rel8.Expr ( Expr )
34import Rel8.Expr.Function ( binaryOperator, function, nullaryFunction )
37import Rel8.Expr.Function ( binaryOperator, function, nullaryFunction )
35−import Rel8.Type.Array1D ( Array1D )
36
38
37-- text
39-- text
38import Data.Text (Text)
40import Data.Text (Text)
@@ -50,24 +52,32 @@ infixr 6 ++.
50
52
51
53
52-- | Matches regular expression, case sensitive
54-- | Matches regular expression, case sensitive
55+--
56+-- Corresponds to the @~.@ operator.
53(~.) :: Expr Text -> Expr Text -> Expr Bool
57(~.) :: Expr Text -> Expr Text -> Expr Bool
54(~.) = binaryOperator "~."
58(~.) = binaryOperator "~."
55infix 2 ~.
59infix 2 ~.
56
60
57
61
58-- | Matches regular expression, case insensitive
62-- | Matches regular expression, case insensitive
63+--
64+-- Corresponds to the @~*@ operator.
59(~*) :: Expr Text -> Expr Text -> Expr Bool
65(~*) :: Expr Text -> Expr Text -> Expr Bool
60(~*) = binaryOperator "~*"
66(~*) = binaryOperator "~*"
61infix 2 ~*
67infix 2 ~*
62
68
63
69
64-- | Does not match regular expression, case sensitive
70-- | Does not match regular expression, case sensitive
71+--
72+-- Corresponds to the @!~@ operator.
65(!~) :: Expr Text -> Expr Text -> Expr Bool
73(!~) :: Expr Text -> Expr Text -> Expr Bool
66(!~) = binaryOperator "!~"
74(!~) = binaryOperator "!~"
67infix 2 !~
75infix 2 !~
68
76
69
77
70-- | Does not match regular expression, case insensitive
78-- | Does not match regular expression, case insensitive
79+--
80+-- Corresponds to the @!~*@ operator.
71(!~*) :: Expr Text -> Expr Text -> Expr Bool
81(!~*) :: Expr Text -> Expr Text -> Expr Bool
72(!~*) = binaryOperator "!~*"
82(!~*) = binaryOperator "!~*"
73infix 2 !~*
83infix 2 !~*
@@ -78,164 +88,209 @@ infix 2 !~*
78-- * Standard SQL functions
88-- * Standard SQL functions
79
89
80
90
91+-- | Corresponds to the @bit_length@ function.
81bitLength :: Expr Text -> Expr Int32
92bitLength :: Expr Text -> Expr Int32
82bitLength = function "bit_length"
93bitLength = function "bit_length"
83
94
84
95
96+-- | Corresponds to the @char_length@ function.
85charLength :: Expr Text -> Expr Int32
97charLength :: Expr Text -> Expr Int32
86charLength = function "char_length"
98charLength = function "char_length"
87
99
88
100
101+-- | Corresponds to the @lower@ function.
89lower :: Expr Text -> Expr Text
102lower :: Expr Text -> Expr Text
90lower = function "lower"
103lower = function "lower"
91
104
92
105
106+-- | Corresponds to the @octet_length@ function.
93octetLength :: Expr Text -> Expr Int32
107octetLength :: Expr Text -> Expr Int32
94octetLength = function "octet_length"
108octetLength = function "octet_length"
95
109
96
110
111+-- | Corresponds to the @upper@ function.
97upper :: Expr Text -> Expr Text
112upper :: Expr Text -> Expr Text
98upper = function "upper"
113upper = function "upper"
99
114
100
115
101−-- * PostgreSQL functions
116+-- | Corresponds to the @ascii@ function.
102ascii :: Expr Text -> Expr Int32
117ascii :: Expr Text -> Expr Int32
103ascii = function "ascii"
118ascii = function "ascii"
104
119
105
120
121+-- | Corresponds to the @btrim@ function.
106btrim :: Expr Text -> Maybe (Expr Text) -> Expr Text
122btrim :: Expr Text -> Maybe (Expr Text) -> Expr Text
107btrim a (Just b) = function "btrim" a b
123btrim a (Just b) = function "btrim" a b
108btrim a Nothing = function "btrim" a
124btrim a Nothing = function "btrim" a
109
125
110
126
127+-- | Corresponds to the @chr@ function.
111chr :: Expr Int32 -> Expr Text
128chr :: Expr Int32 -> Expr Text
112chr = function "chr"
129chr = function "chr"
113
130
114
131
132+-- | Corresponds to the @convert@ function.
115convert :: Expr ByteString -> Expr Text -> Expr Text -> Expr ByteString
133convert :: Expr ByteString -> Expr Text -> Expr Text -> Expr ByteString
116convert = function "convert"
134convert = function "convert"
117
135
118
136
137+-- | Corresponds to the @convert_from@ function.
119convertFrom :: Expr ByteString -> Expr Text -> Expr Text
138convertFrom :: Expr ByteString -> Expr Text -> Expr Text
120convertFrom = function "convert_from"
139convertFrom = function "convert_from"
121
140
122
141
142+-- | Corresponds to the @convert_to@ function.
123convertTo :: Expr Text -> Expr Text -> Expr ByteString
143convertTo :: Expr Text -> Expr Text -> Expr ByteString
124convertTo = function "convert_to"
144convertTo = function "convert_to"
125
145
126
146
147+-- | Corresponds to the @decode@ function.
127decode :: Expr Text -> Expr Text -> Expr ByteString
148decode :: Expr Text -> Expr Text -> Expr ByteString
128decode = function "decode"
149decode = function "decode"
129
150
130
151
152+-- | Corresponds to the @encode@ function.
131encode :: Expr ByteString -> Expr Text -> Expr Text
153encode :: Expr ByteString -> Expr Text -> Expr Text
132encode = function "encode"
154encode = function "encode"
133
155
134
156
157+-- | Corresponds to the @initcap@ function.
135initcap :: Expr Text -> Expr Text
158initcap :: Expr Text -> Expr Text
136initcap = function "initcap"
159initcap = function "initcap"
137
160
138
161
162+-- | Corresponds to the @left@ function.
139left :: Expr Text -> Expr Int32 -> Expr Text
163left :: Expr Text -> Expr Int32 -> Expr Text
140left = function "left"
164left = function "left"
141
165
142
166
167+-- | Corresponds to the @length@ function.
143length :: Expr Text -> Expr Int32
168length :: Expr Text -> Expr Int32
144length = function "length"
169length = function "length"
145
170
146
171
172+-- | Corresponds to the @length@ function.
147lengthEncoding :: Expr ByteString -> Expr Text -> Expr Int32
173lengthEncoding :: Expr ByteString -> Expr Text -> Expr Int32
148lengthEncoding = function "length"
174lengthEncoding = function "length"
149
175
150
176
177+-- | Corresponds to the @lpad@ function.
151lpad :: Expr Text -> Expr Int32 -> Maybe (Expr Text) -> Expr Text
178lpad :: Expr Text -> Expr Int32 -> Maybe (Expr Text) -> Expr Text
152lpad a b (Just c) = function "lpad" a b c
179lpad a b (Just c) = function "lpad" a b c
153lpad a b Nothing = function "lpad" a b
180lpad a b Nothing = function "lpad" a b
154
181
155
182
183+-- | Corresponds to the @ltrim@ function.
156ltrim :: Expr Text -> Maybe (Expr Text) -> Expr Text
184ltrim :: Expr Text -> Maybe (Expr Text) -> Expr Text
157ltrim a (Just b) = function "ltrim" a b
185ltrim a (Just b) = function "ltrim" a b
158ltrim a Nothing = function "ltrim" a
186ltrim a Nothing = function "ltrim" a
159
187
160
188
189+-- | Corresponds to the @md5@ function.
161md5 :: Expr Text -> Expr Text
190md5 :: Expr Text -> Expr Text
162md5 = function "md5"
191md5 = function "md5"
163
192
164
193
194+-- | Corresponds to the @pg_client_encoding()@ expression.
165pgClientEncoding :: Expr Text
195pgClientEncoding :: Expr Text
166pgClientEncoding = nullaryFunction "pg_client_encoding"
196pgClientEncoding = nullaryFunction "pg_client_encoding"
167
197
168
198
199+-- | Corresponds to the @quote_ident@ function.
169quoteIdent :: Expr Text -> Expr Text
200quoteIdent :: Expr Text -> Expr Text
170quoteIdent = function "quote_ident"
201quoteIdent = function "quote_ident"
171
202
172
203
204+-- | Corresponds to the @quote_literal@ function.
173quoteLiteral :: Expr Text -> Expr Text
205quoteLiteral :: Expr Text -> Expr Text
174quoteLiteral = function "quote_literal"
206quoteLiteral = function "quote_literal"
175
207
176
208
209+-- | Corresponds to the @quote_nullable@ function.
177quoteNullable :: Expr Text -> Expr Text
210quoteNullable :: Expr Text -> Expr Text
178quoteNullable = function "quote_nullable"
211quoteNullable = function "quote_nullable"
179
212
180
213
214+-- | Corresponds to the @regexp_replace@ function.
181regexpReplace :: ()
215regexpReplace :: ()
182 => Expr Text -> Expr Text -> Expr Text -> Maybe (Expr Text) -> Expr Text
216 => Expr Text -> Expr Text -> Expr Text -> Maybe (Expr Text) -> Expr Text
183regexpReplace a b c (Just d) = function "regexp_replace" a b c d
217regexpReplace a b c (Just d) = function "regexp_replace" a b c d
184regexpReplace a b c Nothing = function "regexp_replace" a b c
218regexpReplace a b c Nothing = function "regexp_replace" a b c
185
219
186
220
221+-- | Corresponds to the @regexp_split_to_array@ function.
187regexpSplitToArray :: ()
222regexpSplitToArray :: ()
188− => Expr Text -> Expr Text -> Maybe (Expr Text) -> Expr (Array1D Text)
223+ => Expr Text -> Expr Text -> Maybe (Expr Text) -> Expr [Text]
189regexpSplitToArray a b (Just c) = function "regexp_split_to_array" a b c
224regexpSplitToArray a b (Just c) = function "regexp_split_to_array" a b c
190regexpSplitToArray a b Nothing = function "regexp_split_to_array" a b
225regexpSplitToArray a b Nothing = function "regexp_split_to_array" a b
191
226
192
227
228+-- | Corresponds to the @repeat@ function.
193repeat :: Expr Text -> Expr Int32 -> Expr Text
229repeat :: Expr Text -> Expr Int32 -> Expr Text
194repeat = function "repeat"
230repeat = function "repeat"
195
231
196
232
233+-- | Corresponds to the @replace@ function.
197replace :: Expr Text -> Expr Text -> Expr Text -> Expr Text
234replace :: Expr Text -> Expr Text -> Expr Text -> Expr Text
198replace = function "replace"
235replace = function "replace"
199
236
200
237
238+-- | Corresponds to the @reverse@ function.
201reverse :: Expr Text -> Expr Text
239reverse :: Expr Text -> Expr Text
202reverse = function "reverse"
240reverse = function "reverse"
203
241
204
242
243+-- | Corresponds to the @right@ function.
205right :: Expr Text -> Expr Int32 -> Expr Text
244right :: Expr Text -> Expr Int32 -> Expr Text
206right = function "right"
245right = function "right"
207
246
208
247
248+-- | Corresponds to the @rpad@ function.
209rpad :: Expr Text -> Expr Int32 -> Maybe (Expr Text) -> Expr Text
249rpad :: Expr Text -> Expr Int32 -> Maybe (Expr Text) -> Expr Text
210rpad a b (Just c) = function "rpad" a b c
250rpad a b (Just c) = function "rpad" a b c
211rpad a b Nothing = function "rpad" a b
251rpad a b Nothing = function "rpad" a b
212
252
213
253
254+-- | Corresponds to the @rtrim@ function.
214rtrim :: Expr Text -> Maybe (Expr Text) -> Expr Text
255rtrim :: Expr Text -> Maybe (Expr Text) -> Expr Text
215rtrim a (Just b) = function "rtrim" a b
256rtrim a (Just b) = function "rtrim" a b
216rtrim a Nothing = function "rtrim" a
257rtrim a Nothing = function "rtrim" a
217
258
218
259
260+-- | Corresponds to the @split_part@ function.
219splitPart :: Expr Text -> Expr Text -> Expr Int32 -> Expr Text
261splitPart :: Expr Text -> Expr Text -> Expr Int32 -> Expr Text
220splitPart = function "split_part"
262splitPart = function "split_part"
221
263
222
264
265+-- | Corresponds to the @strpos@ function.
223strpos :: Expr Text -> Expr Text -> Expr Int32
266strpos :: Expr Text -> Expr Text -> Expr Int32
224strpos = function "strpos"
267strpos = function "strpos"
225
268
226
269
270+-- | Corresponds to the @substr@ function.
227substr :: Expr Text -> Expr Int32 -> Maybe (Expr Int32) -> Expr Text
271substr :: Expr Text -> Expr Int32 -> Maybe (Expr Int32) -> Expr Text
228substr a b (Just c) = function "substr" a b c
272substr a b (Just c) = function "substr" a b c
229substr a b Nothing = function "substr" a b
273substr a b Nothing = function "substr" a b
230
274
231
275
276+-- | Corresponds to the @translate@ function.
232−toAscii :: Expr Text -> Expr Text -> Expr Text
277+translate :: Expr Text -> Expr Text -> Expr Text -> Expr Text
233−toAscii = function "toAscii"
278+translate = function "translate"
234
279
235
280
281+-- | @like x y@ corresponds to the expression @y LIKE x@.
282+--
283+-- Note that the arguments to @like@ are swapped. This is to aid currying, so
284+-- you can write expressions like
285+-- @filter (like "Rel%" . packageName) =<< each haskellPackages@
236−toHex :: Expr Int32 -> Expr Text
286+like :: Expr Text -> Expr Text -> Expr Bool
237−toHex = function "toHex"
287+like = flip (binaryOperator "LIKE")
238
288
239
289
290+-- | @ilike x y@ corresponds to the expression @y ILIKE x@.
291+--
292+-- Note that the arguments to @ilike@ are swapped. This is to aid currying, so
293+-- you can write expressions like
294+-- @filter (ilike "Rel%" . packageName) =<< each haskellPackages@
240−translate :: Expr Text -> Expr Text -> Expr Text -> Expr Text
295+ilike :: Expr Text -> Expr Text -> Expr Bool
241−translate = function "translate"
296+ilike = flip (binaryOperator "ILIKE")
src/Rel8/Expr/Time.hs+36−24
@@ -13,12 +13,13 @@ module Rel8.Expr.Time
13 , diffTime
13 , diffTime
14 , subtractTime
14 , subtractTime
15
15
16− -- Working with @DiffTime@
16+ -- * Working with @CalendarDiffTime@
17 , scaleInterval
17 , scaleInterval
18 , second, seconds
18 , second, seconds
19 , minute, minutes
19 , minute, minutes
20 , hour, hours
20 , hour, hours
21 , day, days
21 , day, days
22+ , week, weeks
22 , month, months
23 , month, months
23 , year, years
24 , year, years
24 ) where
25 ) where
@@ -30,11 +31,12 @@ import Prelude
30-- rel8
31-- rel8
31import Rel8.Expr ( Expr )
32import Rel8.Expr ( Expr )
32import Rel8.Expr.Function ( binaryOperator, nullaryFunction )
33import Rel8.Expr.Function ( binaryOperator, nullaryFunction )
33−import Rel8.Expr.Opaleye ( unsafeCastExpr, unsafeLiteral )
34+import Rel8.Expr.Opaleye ( castExpr, unsafeCastExpr, unsafeLiteral )
34
35
35-- time
36-- time
36import Data.Time.Calendar ( Day )
37import Data.Time.Calendar ( Day )
37−import Data.Time.Clock ( DiffTime, UTCTime )
38+import Data.Time.Clock ( UTCTime )
39+import Data.Time.LocalTime ( CalendarDiffTime )
38
40
39
41
40-- | Corresponds to @date(now())@.
42-- | Corresponds to @date(now())@.
@@ -73,83 +75,93 @@ now = nullaryFunction "now"
73
75
74
76
75-- | Add a time interval to a point in time, yielding a new point in time.
77-- | Add a time interval to a point in time, yielding a new point in time.
76−addTime :: Expr DiffTime -> Expr UTCTime -> Expr UTCTime
78+addTime :: Expr CalendarDiffTime -> Expr UTCTime -> Expr UTCTime
77addTime = flip (binaryOperator "+")
79addTime = flip (binaryOperator "+")
78
80
79
81
80-- | Find the duration between two times.
82-- | Find the duration between two times.
81−diffTime :: Expr UTCTime -> Expr UTCTime -> Expr DiffTime
83+diffTime :: Expr UTCTime -> Expr UTCTime -> Expr CalendarDiffTime
82diffTime = binaryOperator "-"
84diffTime = binaryOperator "-"
83
85
84
86
85-- | Subtract a time interval from a point in time, yielding a new point in time.
87-- | Subtract a time interval from a point in time, yielding a new point in time.
86−subtractTime :: Expr DiffTime -> Expr UTCTime -> Expr UTCTime
88+subtractTime :: Expr CalendarDiffTime -> Expr UTCTime -> Expr UTCTime
87subtractTime = flip (binaryOperator "-")
89subtractTime = flip (binaryOperator "-")
88
90
89
91
90−scaleInterval :: Expr Double -> Expr DiffTime -> Expr DiffTime
92+scaleInterval :: Expr Double -> Expr CalendarDiffTime -> Expr CalendarDiffTime
91scaleInterval = binaryOperator "*"
93scaleInterval = binaryOperator "*"
92
94
93
95
94-- | An interval of one second.
96-- | An interval of one second.
95−second :: Expr DiffTime
97+second :: Expr CalendarDiffTime
96second = singleton "second"
98second = singleton "second"
97
99
98
100
99−-- | Create a literal interval from an integral number of seconds.
101+-- | Create a literal interval from a number of seconds.
100−seconds :: Expr Double -> Expr DiffTime
102+seconds :: Expr Double -> Expr CalendarDiffTime
101seconds = (`scaleInterval` second)
103seconds = (`scaleInterval` second)
102
104
103
105
104-- | An interval of one minute.
106-- | An interval of one minute.
105−minute :: Expr DiffTime
107+minute :: Expr CalendarDiffTime
106minute = singleton "minute"
108minute = singleton "minute"
107
109
108
110
109−-- | Create a literal interval from an integral number of minutes.
111+-- | Create a literal interval from a number of minutes.
110−minutes :: Expr Double -> Expr DiffTime
112+minutes :: Expr Double -> Expr CalendarDiffTime
111minutes = (`scaleInterval` minute)
113minutes = (`scaleInterval` minute)
112
114
113
115
114-- | An interval of one hour.
116-- | An interval of one hour.
115−hour :: Expr DiffTime
117+hour :: Expr CalendarDiffTime
116hour = singleton "hour"
118hour = singleton "hour"
117
119
118
120
119−-- | Create a literal interval from an integral number of hours.
121+-- | Create a literal interval from a number of hours.
120−hours :: Expr Double -> Expr DiffTime
122+hours :: Expr Double -> Expr CalendarDiffTime
121hours = (`scaleInterval` hour)
123hours = (`scaleInterval` hour)
122
124
123
125
124-- | An interval of one day.
126-- | An interval of one day.
125−day :: Expr DiffTime
127+day :: Expr CalendarDiffTime
126day = singleton "day"
128day = singleton "day"
127
129
128
130
129-- | Create a literal interval from a number of days.
131-- | Create a literal interval from a number of days.
130−days :: Expr Double -> Expr DiffTime
132+days :: Expr Double -> Expr CalendarDiffTime
131days = (`scaleInterval` day)
133days = (`scaleInterval` day)
132
134
133
135
136+-- | An interval of one week.
137+week :: Expr CalendarDiffTime
138+week = singleton "week"
139+
140+
141+-- | Create a literal interval from a number of weeks.
142+weeks :: Expr Double -> Expr CalendarDiffTime
143+weeks = (`scaleInterval` week)
144+
145+
134-- | An interval of one month.
146-- | An interval of one month.
135−month :: Expr DiffTime
147+month :: Expr CalendarDiffTime
136month = singleton "month"
148month = singleton "month"
137
149
138
150
139-- | Create a literal interval from a number of months.
151-- | Create a literal interval from a number of months.
140−months :: Expr Double -> Expr DiffTime
152+months :: Expr Double -> Expr CalendarDiffTime
141months = (`scaleInterval` month)
153months = (`scaleInterval` month)
142
154
143
155
144-- | An interval of one year.
156-- | An interval of one year.
145−year :: Expr DiffTime
157+year :: Expr CalendarDiffTime
146year = singleton "year"
158year = singleton "year"
147
159
148
160
149-- | Create a literal interval from a number of years.
161-- | Create a literal interval from a number of years.
150−years :: Expr Double -> Expr DiffTime
162+years :: Expr Double -> Expr CalendarDiffTime
151years = (`scaleInterval` year)
163years = (`scaleInterval` year)
152
164
153
165
154−singleton :: String -> Expr DiffTime
166+singleton :: String -> Expr CalendarDiffTime
155−singleton unit = unsafeLiteral $ "'1 " ++ unit ++ "'"
167+singleton unit = castExpr $ unsafeLiteral $ "'1 " ++ unit ++ "'"
src/Rel8/Expr/Window.hsnew file+121
@@ -0,0 +1,121 @@
1+module Rel8.Expr.Window
2+ ( cumulative
3+ , rowNumber
4+ , rank
5+ , denseRank
6+ , percentRank
7+ , cumeDist
8+ , ntile
9+ , lag
10+ , lead
11+ , firstValue
12+ , lastValue
13+ , nthValue
14+ )
15+where
16+
17+-- base
18+import Data.Int ( Int32, Int64 )
19+import Prelude
20+
21+-- opaleye
22+import qualified Opaleye.Internal.Aggregate as Opaleye
23+import qualified Opaleye.Internal.PackMap as Opaleye
24+import qualified Opaleye.Internal.Window as Opaleye
25+import qualified Opaleye.Window as Opaleye
26+
27+-- profunctors
28+import Data.Profunctor (dimap)
29+
30+-- rel8
31+import Rel8.Aggregate ( Aggregate( Aggregate ) )
32+import Rel8.Expr ( Expr )
33+import Rel8.Expr.Opaleye ( fromColumn, fromPrimExpr, toColumn, toPrimExpr )
34+import Rel8.Schema.Null ( Nullify )
35+import Rel8.Window ( Window( Window ) )
36+
37+
38+cumulative :: (a -> Aggregate b) -> Window a (Expr b)
39+cumulative f =
40+ fromWindowFunction $ Opaleye.aggregatorWindowFunction (fromAggregate f) id
41+
42+
43+-- | [@row_number()@](https://www.postgresql.org/docs/current/functions-window.html)
44+rowNumber :: Window a (Expr Int64)
45+rowNumber = fromWindowFunction $ fromPrimExpr . fromColumn <$> Opaleye.rowNumber
46+
47+
48+-- | [@rank()@](https://www.postgresql.org/docs/current/functions-window.html)
49+rank :: Window a (Expr Int64)
50+rank = fromWindowFunction $ fromPrimExpr . fromColumn <$> Opaleye.rank
51+
52+
53+-- | [@dense_rank()@](https://www.postgresql.org/docs/current/functions-window.html)
54+denseRank :: Window a (Expr Int64)
55+denseRank = fromWindowFunction $ fromPrimExpr . fromColumn <$> Opaleye.denseRank
56+
57+
58+-- | [@percent_rank()@](https://www.postgresql.org/docs/current/functions-window.html)
59+percentRank :: Window a (Expr Double)
60+percentRank = fromWindowFunction $ fromPrimExpr . fromColumn <$> Opaleye.percentRank
61+
62+
63+-- | [@cume_dist()@](https://www.postgresql.org/docs/current/functions-window.html)
64+cumeDist :: Window a (Expr Double)
65+cumeDist = fromWindowFunction $ fromPrimExpr . fromColumn <$> Opaleye.cumeDist
66+
67+
68+-- | [@ntile(num_buckets)@](https://www.postgresql.org/docs/current/functions-window.html)
69+ntile :: Expr Int32 -> Window a (Expr Int32)
70+ntile buckets = fromWindowFunction $ fromPrimExpr . fromColumn <$>
71+ Opaleye.ntile (toColumn (toPrimExpr buckets))
72+
73+
74+-- | [@lag(value, offset, default)@](https://www.postgresql.org/docs/current/functions-window.html)
75+lag :: Expr Int32 -> Expr a -> Window (Expr a) (Expr a)
76+lag offset def =
77+ fromWindowFunction $
78+ dimap (toColumn . toPrimExpr) (fromPrimExpr . fromColumn) $
79+ Opaleye.lag (toColumn (toPrimExpr offset)) (toColumn (toPrimExpr def))
80+
81+
82+-- | [@lead(value, offset, default)@](https://www.postgresql.org/docs/current/functions-window.html)
83+lead :: Expr Int32 -> Expr a -> Window (Expr a) (Expr a)
84+lead offset def =
85+ fromWindowFunction $
86+ dimap (toColumn . toPrimExpr) (fromPrimExpr . fromColumn) $
87+ Opaleye.lead (toColumn (toPrimExpr offset)) (toColumn (toPrimExpr def))
88+
89+
90+-- | [@first_value(value)@](https://www.postgresql.org/docs/current/functions-window.html)
91+firstValue :: Window (Expr a) (Expr a)
92+firstValue =
93+ fromWindowFunction $
94+ dimap (toColumn . toPrimExpr) (fromPrimExpr . fromColumn)
95+ Opaleye.firstValue
96+
97+
98+-- | [@last_value(value)@](https://www.postgresql.org/docs/current/functions-window.html)
99+lastValue :: Window (Expr a) (Expr a)
100+lastValue =
101+ fromWindowFunction $
102+ dimap (toColumn . toPrimExpr) (fromPrimExpr . fromColumn)
103+ Opaleye.lastValue
104+
105+
106+-- | [@nth_value(value, n)@](https://www.postgresql.org/docs/current/functions-window.html)
107+nthValue :: Expr Int32 -> Window (Expr a) (Expr (Nullify a))
108+nthValue n =
109+ fromWindowFunction $
110+ dimap (toColumn . toPrimExpr) (fromPrimExpr . fromColumn) $
111+ Opaleye.nthValue (toColumn (toPrimExpr n))
112+
113+
114+fromAggregate :: (a -> Aggregate b) -> Opaleye.Aggregator a (Expr b)
115+fromAggregate f = Opaleye.Aggregator $ Opaleye.PackMap $ \w a -> case f a of
116+ Aggregate (Opaleye.Aggregator (Opaleye.PackMap x)) -> x w ()
117+
118+
119+fromWindowFunction :: Opaleye.WindowFunction a b -> Window a b
120+fromWindowFunction (Opaleye.WindowFunction (Opaleye.PackMap w)) =
121+ Window $ Opaleye.Windows $ Opaleye.PackMap $ \f -> w $ \o -> f (o, mempty)
src/Rel8/FCF.hsnew file+26
@@ -0,0 +1,26 @@
1+{-# language DataKinds #-}
2+{-# language PolyKinds #-}
3+{-# language StandaloneKindSignatures #-}
4+{-# language TypeFamilies #-}
5+
6+module Rel8.FCF
7+ ( Exp, Eval
8+ , Id
9+ )
10+where
11+
12+-- base
13+import Data.Kind ( Type )
14+import Prelude ()
15+
16+
17+type Exp :: Type -> Type
18+type Exp e = e -> Type
19+
20+
21+type Eval :: Exp e -> e
22+type family Eval a
23+
24+
25+data Id :: a -> Exp a
26+type instance Eval (Id a) = a
src/Rel8/Generic/Construction.hsnew file+352
@@ -0,0 +1,352 @@
1+{-# language AllowAmbiguousTypes #-}
2+{-# language ConstraintKinds #-}
3+{-# language DataKinds #-}
4+{-# language FlexibleContexts #-}
5+{-# language NamedFieldPuns #-}
6+{-# language ScopedTypeVariables #-}
7+{-# language StandaloneKindSignatures #-}
8+{-# language TypeApplications #-}
9+{-# language TypeFamilies #-}
10+{-# language UndecidableInstances #-}
11+{-# language ViewPatterns #-}
12+
13+module Rel8.Generic.Construction
14+ ( GGBuildable
15+ , GGBuild, ggbuild
16+ , GGConstructable
17+ , GGConstruct, ggconstruct
18+ , GGDeconstruct, ggdeconstruct
19+ , GGName, ggname
20+ , GGAggregate, ggaggregate
21+ )
22+where
23+
24+-- base
25+import Data.Bifunctor ( first )
26+import Data.Kind ( Constraint, Type )
27+import Data.List.NonEmpty ( NonEmpty( (:|) ) )
28+import GHC.TypeLits ( Symbol )
29+import Prelude
30+
31+-- rel8
32+import Rel8.Aggregate ( Aggregate( Aggregate ) )
33+import Rel8.Expr ( Expr )
34+import Rel8.Expr.Aggregate ( groupByExpr )
35+import Rel8.Expr.Eq ( (==.) )
36+import Rel8.Expr.Null ( nullify, snull, unsafeUnnullify )
37+import Rel8.Expr.Serialize ( litExpr )
38+import Rel8.FCF ( Eval, Exp, Id )
39+import Rel8.Generic.Construction.ADT
40+ ( GConstructorADT, GMakeableADT, gmakeADT
41+ , GConstructableADT
42+ , GBuildADT, gbuildADT, gunbuildADT
43+ , GConstructADT, gconstructADT, gdeconstructADT
44+ , RepresentableConstructors, GConstructors, gcindex, gctabulate
45+ , RepresentableFields, gfindex, gftabulate
46+ )
47+import Rel8.Generic.Construction.Record
48+ ( GConstructor
49+ , GConstructable, GConstruct, gconstruct, gdeconstruct
50+ , Representable, gindex, gtabulate
51+ )
52+import Rel8.Generic.Table ( GGColumns )
53+import Rel8.Kind.Algebra
54+ ( SAlgebra( SProduct, SSum )
55+ , KnownAlgebra, algebraSing
56+ )
57+import qualified Rel8.Kind.Algebra as K
58+import Rel8.Schema.Context.Nullify ( sguard, snullify )
59+import Rel8.Schema.HTable ( HTable )
60+import Rel8.Schema.HTable.Identity ( HIdentity( HIdentity ) )
61+import qualified Rel8.Schema.Kind as K
62+import Rel8.Schema.Name ( Name( Name ) )
63+import Rel8.Schema.Null ( Nullity( Null, NotNull ) )
64+import Rel8.Schema.Spec ( Spec( Spec, nullity, info ) )
65+import Rel8.Table
66+ ( TTable, TColumns
67+ , Table, fromColumns, toColumns
68+ )
69+import Rel8.Table.Bool ( case_ )
70+import Rel8.Type.Tag ( Tag )
71+
72+
73+type GGBuildable :: K.Algebra -> Symbol -> (K.Context -> Exp (Type -> Type)) -> Constraint
74+type GGBuildable algebra name rep =
75+ ( KnownAlgebra algebra
76+ , Eval (GGColumns algebra TColumns (Eval (rep Aggregate))) ~ Eval (GGColumns algebra TColumns (Eval (rep Expr)))
77+ , Eval (GGColumns algebra TColumns (Eval (rep Expr))) ~ Eval (GGColumns algebra TColumns (Eval (rep Expr)))
78+ , Eval (GGColumns algebra TColumns (Eval (rep Name))) ~ Eval (GGColumns algebra TColumns (Eval (rep Expr)))
79+ , HTable (Eval (GGColumns algebra TColumns (Eval (rep Expr))))
80+ , GGBuildable' algebra name rep
81+ )
82+
83+
84+type GGBuildable' :: K.Algebra -> Symbol -> (K.Context -> Exp (Type -> Type)) -> Constraint
85+type family GGBuildable' algebra name rep where
86+ GGBuildable' 'K.Product name rep =
87+ ( name ~ GConstructor (Eval (rep Expr))
88+ , Representable Id (Eval (rep Expr))
89+ , GConstructable (TTable Expr) TColumns Id Expr (Eval (rep Expr))
90+ )
91+ GGBuildable' 'K.Sum name rep =
92+ ( Representable Id (GConstructorADT name (Eval (rep Expr)))
93+ , GMakeableADT (TTable Expr) TColumns Id Expr name (Eval (rep Expr))
94+ )
95+
96+
97+type GGBuild :: K.Algebra -> Symbol -> (K.Context -> Exp (Type -> Type)) -> Type -> Type
98+type family GGBuild algebra name rep r where
99+ GGBuild 'K.Product _name rep r =
100+ GConstruct Id (Eval (rep Expr)) r
101+ GGBuild 'K.Sum name rep r =
102+ GConstruct Id (GConstructorADT name (Eval (rep Expr))) r
103+
104+
105+ggbuild :: forall algebra name rep a. GGBuildable algebra name rep
106+ => (Eval (GGColumns algebra TColumns (Eval (rep Expr))) Expr -> a)
107+ -> GGBuild algebra name rep a
108+ggbuild gfromColumns = case algebraSing @algebra of
109+ SProduct ->
110+ gtabulate @Id @(Eval (rep Expr)) @a $
111+ gfromColumns .
112+ gconstruct
113+ @(TTable Expr)
114+ @TColumns
115+ @Id
116+ @Expr
117+ @(Eval (rep Expr))
118+ (const toColumns)
119+ SSum ->
120+ gtabulate @Id @(GConstructorADT name (Eval (rep Expr))) @a $
121+ gfromColumns .
122+ gmakeADT
123+ @(TTable Expr)
124+ @TColumns
125+ @Id
126+ @Expr
127+ @name
128+ @(Eval (rep Expr))
129+ (const toColumns)
130+ (\Spec {info} -> snull info)
131+ (\Spec {nullity} -> case nullity of
132+ Null -> id
133+ NotNull -> nullify)
134+ (HIdentity . litExpr)
135+
136+
137+type GGConstructable :: K.Algebra -> (K.Context -> Exp (Type -> Type)) -> Constraint
138+type GGConstructable algebra rep =
139+ ( KnownAlgebra algebra
140+ , Eval (GGColumns algebra TColumns (Eval (rep Aggregate))) ~ Eval (GGColumns algebra TColumns (Eval (rep Expr)))
141+ , Eval (GGColumns algebra TColumns (Eval (rep Expr))) ~ Eval (GGColumns algebra TColumns (Eval (rep Expr)))
142+ , Eval (GGColumns algebra TColumns (Eval (rep Name))) ~ Eval (GGColumns algebra TColumns (Eval (rep Expr)))
143+ , HTable (Eval (GGColumns algebra TColumns (Eval (rep Expr))))
144+ , GGConstructable' algebra rep
145+ )
146+
147+
148+type GGConstructable' :: K.Algebra -> (K.Context -> Exp (Type -> Type)) -> Constraint
149+type family GGConstructable' algebra rep where
150+ GGConstructable' 'K.Product rep =
151+ ( Representable Id (Eval (rep Aggregate))
152+ , Representable Id (Eval (rep Expr))
153+ , Representable Id (Eval (rep Name))
154+ , GConstructable (TTable Aggregate) TColumns Id Aggregate (Eval (rep Aggregate))
155+ , GConstructable (TTable Expr) TColumns Id Expr (Eval (rep Expr))
156+ , GConstructable (TTable Name) TColumns Id Name (Eval (rep Name))
157+ )
158+ GGConstructable' 'K.Sum rep =
159+ ( RepresentableConstructors Id (Eval (rep Expr))
160+ , RepresentableFields Id (Eval (rep Aggregate))
161+ , RepresentableFields Id (Eval (rep Expr))
162+ , RepresentableFields Id (Eval (rep Name))
163+ , Functor (GConstructors Id (Eval (rep Expr)))
164+ , GConstructableADT (TTable Aggregate) TColumns Id Aggregate (Eval (rep Aggregate))
165+ , GConstructableADT (TTable Expr) TColumns Id Expr (Eval (rep Expr))
166+ , GConstructableADT (TTable Name) TColumns Id Name (Eval (rep Name))
167+ )
168+
169+
170+type GGConstruct :: K.Algebra -> (K.Context -> Exp (Type -> Type)) -> Type -> Type
171+type family GGConstruct algebra rep r where
172+ GGConstruct 'K.Product rep r = GConstruct Id (Eval (rep Expr)) r -> r
173+ GGConstruct 'K.Sum rep r = GConstructADT Id (Eval (rep Expr)) r r
174+
175+
176+ggconstruct :: forall algebra rep a. GGConstructable algebra rep
177+ => (Eval (GGColumns algebra TColumns (Eval (rep Expr))) Expr -> a)
178+ -> GGConstruct algebra rep a -> a
179+ggconstruct gfromColumns f = case algebraSing @algebra of
180+ SProduct ->
181+ f $
182+ gtabulate @Id @(Eval (rep Expr)) @a $
183+ gfromColumns .
184+ gconstruct
185+ @(TTable Expr)
186+ @TColumns
187+ @Id
188+ @Expr
189+ @(Eval (rep Expr))
190+ (const toColumns)
191+ SSum ->
192+ gcindex @Id @(Eval (rep Expr)) @a f $
193+ fmap gfromColumns $
194+ gconstructADT
195+ @(TTable Expr)
196+ @TColumns
197+ @Id
198+ @Expr
199+ @(Eval (rep Expr))
200+ (const toColumns)
201+ (\Spec {info} -> snull info)
202+ (\Spec {nullity} -> case nullity of
203+ Null -> id
204+ NotNull -> nullify)
205+ (HIdentity . litExpr)
206+
207+
208+type GGDeconstruct :: K.Algebra -> (K.Context -> Exp (Type -> Type)) -> Type -> Type -> Type
209+type family GGDeconstruct algebra rep a r where
210+ GGDeconstruct 'K.Product rep a r =
211+ GConstruct Id (Eval (rep Expr)) r -> a -> r
212+ GGDeconstruct 'K.Sum rep a r =
213+ GConstructADT Id (Eval (rep Expr)) r (a -> r)
214+
215+
216+ggdeconstruct :: forall algebra rep a r. (GGConstructable algebra rep, Table Expr r)
217+ => (a -> Eval (GGColumns algebra TColumns (Eval (rep Expr))) Expr)
218+ -> GGDeconstruct algebra rep a r
219+ggdeconstruct gtoColumns = case algebraSing @algebra of
220+ SProduct -> \build ->
221+ gindex @Id @(Eval (rep Expr)) @r build .
222+ gdeconstruct
223+ @(TTable Expr)
224+ @TColumns
225+ @Id
226+ @Expr
227+ @(Eval (rep Expr))
228+ (const fromColumns) .
229+ gtoColumns
230+ SSum ->
231+ gctabulate @Id @(Eval (rep Expr)) @r @(a -> r) $ \constructors as ->
232+ let
233+ (HIdentity tag, cases) =
234+ gdeconstructADT
235+ @(TTable Expr)
236+ @TColumns
237+ @Id
238+ @Expr
239+ @(Eval (rep Expr))
240+ (const fromColumns)
241+ (\Spec {nullity} -> case nullity of
242+ Null -> id
243+ NotNull -> unsafeUnnullify)
244+ constructors $
245+ gtoColumns as
246+ in
247+ case cases of
248+ ((_, r) :| (map (first ((tag ==.) . litExpr)) -> cases')) ->
249+ case_ cases' r
250+
251+
252+type GGName :: K.Algebra -> (K.Context -> Exp (Type -> Type)) -> Type -> Type
253+type family GGName algebra rep a where
254+ GGName 'K.Product rep a = GConstruct Id (Eval (rep Name)) a
255+ GGName 'K.Sum rep a = Name Tag -> GBuildADT Id (Eval (rep Name)) a
256+
257+
258+ggname :: forall algebra rep a. GGConstructable algebra rep
259+ => (Eval (GGColumns algebra TColumns (Eval (rep Expr))) Name -> a)
260+ -> GGName algebra rep a
261+ggname gfromColumns = case algebraSing @algebra of
262+ SProduct ->
263+ gtabulate @Id @(Eval (rep Name)) @a $
264+ gfromColumns .
265+ gconstruct
266+ @(TTable Name)
267+ @TColumns
268+ @Id
269+ @Name
270+ @(Eval (rep Name))
271+ (const toColumns)
272+ SSum -> \tag ->
273+ gftabulate @Id @(Eval (rep Name)) @a $
274+ gfromColumns .
275+ gbuildADT
276+ @(TTable Name)
277+ @TColumns
278+ @Id
279+ @Name
280+ @(Eval (rep Name))
281+ (const toColumns)
282+ (\_ _ (Name a) -> Name a)
283+ (HIdentity tag)
284+
285+
286+type GGAggregate :: K.Algebra -> (K.Context -> Exp (Type -> Type)) -> Type -> Type
287+type family GGAggregate algebra rep r where
288+ GGAggregate 'K.Product rep r =
289+ GConstruct Id (Eval (rep Aggregate)) r ->
290+ GConstruct Id (Eval (rep Expr)) r
291+ GGAggregate 'K.Sum rep r =
292+ GBuildADT Id (Eval (rep Aggregate)) r ->
293+ GBuildADT Id (Eval (rep Expr)) r
294+
295+
296+ggaggregate :: forall algebra rep exprs agg. GGConstructable algebra rep
297+ => (Eval (GGColumns algebra TColumns (Eval (rep Expr))) Aggregate -> agg)
298+ -> (exprs -> Eval (GGColumns algebra TColumns (Eval (rep Expr))) Expr)
299+ -> GGAggregate algebra rep agg -> exprs -> agg
300+ggaggregate gfromColumns gtoColumns agg es = case algebraSing @algebra of
301+ SProduct -> flip f exprs $
302+ gfromColumns .
303+ gconstruct
304+ @(TTable Aggregate)
305+ @TColumns
306+ @Id
307+ @Aggregate
308+ @(Eval (rep Aggregate))
309+ (const toColumns)
310+ where
311+ f =
312+ gindex @Id @(Eval (rep Expr)) @agg .
313+ agg .
314+ gtabulate @Id @(Eval (rep Aggregate)) @agg
315+ exprs =
316+ gdeconstruct
317+ @(TTable Expr)
318+ @TColumns
319+ @Id
320+ @Expr
321+ @(Eval (rep Expr))
322+ (const fromColumns) $
323+ gtoColumns es
324+ SSum -> flip f exprs $
325+ gfromColumns .
326+ gbuildADT
327+ @(TTable Aggregate)
328+ @TColumns
329+ @Id
330+ @Aggregate
331+ @(Eval (rep Aggregate))
332+ (const toColumns)
333+ (\tag' Spec {nullity} (Aggregate a) ->
334+ Aggregate $ sguard (tag ==. litExpr tag') . snullify nullity <$> a)
335+ (HIdentity (groupByExpr tag))
336+ where
337+ f =
338+ gfindex @Id @(Eval (rep Expr)) @agg .
339+ agg .
340+ gftabulate @Id @(Eval (rep Aggregate)) @agg
341+ (HIdentity tag, exprs) =
342+ gunbuildADT
343+ @(TTable Expr)
344+ @TColumns
345+ @Id
346+ @Expr
347+ @(Eval (rep Expr))
348+ (const fromColumns)
349+ (\Spec {nullity} -> case nullity of
350+ Null -> id
351+ NotNull -> unsafeUnnullify) $
352+ gtoColumns es
src/Rel8/Generic/Construction/ADT.hsnew file+478
@@ -0,0 +1,478 @@
1+{-# language AllowAmbiguousTypes #-}
2+{-# language BlockArguments #-}
3+{-# language DataKinds #-}
4+{-# language FlexibleContexts #-}
5+{-# language FlexibleInstances #-}
6+{-# language MultiParamTypeClasses #-}
7+{-# language RankNTypes #-}
8+{-# language ScopedTypeVariables #-}
9+{-# language StandaloneKindSignatures #-}
10+{-# language TupleSections #-}
11+{-# language TypeApplications #-}
12+{-# language TypeFamilies #-}
13+{-# language TypeOperators #-}
14+{-# language UndecidableInstances #-}
15+
16+module Rel8.Generic.Construction.ADT
17+ ( GConstructableADT
18+ , GBuildADT, gbuildADT, gunbuildADT
19+ , GConstructADT, gconstructADT, gdeconstructADT
20+ , GFields, RepresentableFields, gftabulate, gfindex
21+ , GConstructors, RepresentableConstructors, gctabulate, gcindex
22+ , GConstructorADT, GMakeableADT, gmakeADT
23+ )
24+where
25+
26+-- base
27+import Data.Bifunctor ( first )
28+import Data.Functor.Identity ( runIdentity )
29+import Data.Kind ( Constraint, Type )
30+import Data.List.NonEmpty ( NonEmpty )
31+import Data.Proxy ( Proxy( Proxy ) )
32+import GHC.Generics
33+ ( (:+:), (:*:)( (:*:) ), M1, U1
34+ , C, D
35+ , Meta( MetaData, MetaCons )
36+ )
37+import GHC.TypeLits
38+ ( ErrorMessage( (:<>:), Text ), TypeError
39+ , Symbol, KnownSymbol, symbolVal
40+ )
41+import Prelude hiding ( null )
42+
43+-- rel8
44+import Rel8.FCF ( Exp )
45+import Rel8.Generic.Construction.Record
46+ ( GConstruct, GConstructable, gconstruct, gdeconstruct
47+ , GFields, Representable, gtabulate, gindex
48+ , FromColumns, ToColumns
49+ )
50+import Rel8.Generic.Table.ADT ( GColumnsADT, GColumnsADT' )
51+import Rel8.Generic.Table.Record ( GColumns )
52+import Rel8.Schema.HTable ( HTable )
53+import Rel8.Schema.HTable.Identity ( HIdentity )
54+import Rel8.Schema.HTable.Label ( HLabel, hlabel, hunlabel )
55+import Rel8.Schema.HTable.Nullify ( HNullify, hnulls, hnullify, hunnullify )
56+import Rel8.Schema.HTable.Product ( HProduct( HProduct ) )
57+import Rel8.Schema.Null ( Nullify )
58+import Rel8.Schema.Spec ( Spec )
59+import qualified Rel8.Schema.Kind as K
60+import Rel8.Type.Tag ( Tag( Tag ) )
61+
62+-- text
63+import Data.Text ( pack )
64+
65+
66+type Null :: K.Context -> Type
67+type Null context = forall a. Spec a -> context (Nullify a)
68+
69+
70+type Nullifier :: K.Context -> Type
71+type Nullifier context = forall a. Spec a -> context a -> context (Nullify a)
72+
73+
74+type Unnullifier :: K.Context -> Type
75+type Unnullifier context = forall a. Spec a -> context (Nullify a) -> context a
76+
77+
78+type NoConstructor :: Symbol -> Symbol -> ErrorMessage
79+type NoConstructor datatype constructor =
80+ ( 'Text "The type `" ':<>:
81+ 'Text datatype ':<>:
82+ 'Text "` has no constructor `" ':<>:
83+ 'Text constructor ':<>:
84+ 'Text "`."
85+ )
86+
87+
88+type GConstructorADT :: Symbol -> (Type -> Type) -> Type -> Type
89+type family GConstructorADT name rep where
90+ GConstructorADT name (M1 D ('MetaData datatype _ _ _) rep) =
91+ GConstructorADT' name rep (TypeError (NoConstructor datatype name))
92+
93+
94+type GConstructorADT' :: Symbol -> (Type -> Type) -> (Type -> Type) -> Type -> Type
95+type family GConstructorADT' name rep fallback where
96+ GConstructorADT' name (M1 D _ rep) fallback =
97+ GConstructorADT' name rep fallback
98+ GConstructorADT' name (a :+: b) fallback =
99+ GConstructorADT' name a (GConstructorADT' name b fallback)
100+ GConstructorADT' name (M1 C ('MetaCons name _ _) rep) _ = rep
101+ GConstructorADT' _ _ fallback = fallback
102+
103+
104+type GConstructADT
105+ :: (Type -> Exp Type)
106+ -> (Type -> Type) -> Type -> Type -> Type
107+type family GConstructADT f rep r x where
108+ GConstructADT f (M1 D _ rep) r x = GConstructADT f rep r x
109+ GConstructADT f (a :+: b) r x = GConstructADT f a r (GConstructADT f b r x)
110+ GConstructADT f (M1 C _ rep) r x = GConstruct f rep r -> x
111+
112+
113+type GConstructors :: (Type -> Exp Type) -> (Type -> Type) -> Type -> Type
114+type family GConstructors f rep where
115+ GConstructors f (M1 D _ rep) = GConstructors f rep
116+ GConstructors f (a :+: b) = GConstructors f a :*: GConstructors f b
117+ GConstructors f (M1 C _ rep) = (->) (GFields f rep)
118+
119+
120+type RepresentableConstructors :: (Type -> Exp Type) -> (Type -> Type) -> Constraint
121+class RepresentableConstructors f rep where
122+ gctabulate :: (GConstructors f rep r -> a) -> GConstructADT f rep r a
123+ gcindex :: GConstructADT f rep r a -> GConstructors f rep r -> a
124+
125+
126+instance RepresentableConstructors f rep => RepresentableConstructors f (M1 D meta rep) where
127+ gctabulate = gctabulate @f @rep
128+ gcindex = gcindex @f @rep
129+
130+
131+instance (RepresentableConstructors f a, RepresentableConstructors f b) =>
132+ RepresentableConstructors f (a :+: b)
133+ where
134+ gctabulate f =
135+ gctabulate @f @a \a -> gctabulate @f @b \b -> f (a :*: b)
136+ gcindex f (a :*: b) = gcindex @f @b (gcindex @f @a f a) b
137+
138+
139+instance Representable f rep => RepresentableConstructors f (M1 C meta rep) where
140+ gctabulate f = f . gindex @f @rep
141+ gcindex f = f . gtabulate @f @rep
142+
143+
144+type GBuildADT :: (Type -> Exp Type) -> (Type -> Type) -> Type -> Type
145+type family GBuildADT f rep r where
146+ GBuildADT f (M1 D _ rep) r = GBuildADT f rep r
147+ GBuildADT f (a :+: b) r = GBuildADT f a (GBuildADT f b r)
148+ GBuildADT f (M1 C _ rep) r = GConstruct f rep r
149+
150+
151+type GFieldsADT :: (Type -> Exp Type) -> (Type -> Type) -> Type
152+type family GFieldsADT f rep where
153+ GFieldsADT f (M1 D _ rep) = GFieldsADT f rep
154+ GFieldsADT f (a :+: b) = (GFieldsADT f a, GFieldsADT f b)
155+ GFieldsADT f (M1 C _ rep) = GFields f rep
156+
157+
158+type RepresentableFields :: (Type -> Exp Type) -> (Type -> Type) -> Constraint
159+class RepresentableFields f rep where
160+ gftabulate :: (GFieldsADT f rep -> a) -> GBuildADT f rep a
161+ gfindex :: GBuildADT f rep a -> GFieldsADT f rep -> a
162+
163+
164+instance RepresentableFields f rep => RepresentableFields f (M1 D meta rep) where
165+ gftabulate = gftabulate @f @rep
166+ gfindex = gfindex @f @rep
167+
168+
169+instance (RepresentableFields f a, RepresentableFields f b) => RepresentableFields f (a :+: b) where
170+ gftabulate f =
171+ gftabulate @f @a \a -> gftabulate @f @b \b -> f (a, b)
172+ gfindex f (a, b) = gfindex @f @b (gfindex @f @a f a) b
173+
174+
175+instance Representable f rep => RepresentableFields f (M1 C meta rep) where
176+ gftabulate = gtabulate @f @rep
177+ gfindex = gindex @f @rep
178+
179+
180+type GConstructableADT
181+ :: (Type -> Exp Constraint)
182+ -> (Type -> Exp K.HTable)
183+ -> (Type -> Exp Type)
184+ -> K.Context -> (Type -> Type) -> Constraint
185+class GConstructableADT _Table _Columns f context rep where
186+ gbuildADT :: ()
187+ => ToColumns _Table _Columns f context
188+ -> (Tag -> Nullifier context)
189+ -> HIdentity Tag context
190+ -> GFieldsADT f rep
191+ -> GColumnsADT _Columns rep context
192+
193+ gunbuildADT :: ()
194+ => FromColumns _Table _Columns f context
195+ -> Unnullifier context
196+ -> GColumnsADT _Columns rep context
197+ -> (HIdentity Tag context, GFieldsADT f rep)
198+
199+ gconstructADT :: ()
200+ => ToColumns _Table _Columns f context
201+ -> Null context
202+ -> Nullifier context
203+ -> (Tag -> HIdentity Tag context)
204+ -> GConstructors f rep (GColumnsADT _Columns rep context)
205+
206+ gdeconstructADT :: ()
207+ => FromColumns _Table _Columns f context
208+ -> Unnullifier context
209+ -> GConstructors f rep r
210+ -> GColumnsADT _Columns rep context
211+ -> (HIdentity Tag context, NonEmpty (Tag, r))
212+
213+
214+instance
215+ ( htable ~ HLabel "tag" (HIdentity Tag)
216+ , GConstructableADT' _Table _Columns f context htable rep
217+ )
218+ => GConstructableADT _Table _Columns f context (M1 D meta rep)
219+ where
220+ gbuildADT toColumns nullifier =
221+ gbuildADT' @_Table @_Columns @f @context @htable @rep toColumns nullifier .
222+ hlabel
223+
224+ gunbuildADT fromColumns unnullifier =
225+ first hunlabel .
226+ gunbuildADT' @_Table @_Columns @f @context @htable @rep fromColumns unnullifier
227+
228+ gconstructADT toColumns null nullifier mk =
229+ gconstructADT' @_Table @_Columns @f @context @htable @rep toColumns null nullifier
230+ (hlabel . mk)
231+
232+ gdeconstructADT fromColumns unnullifier cases =
233+ first hunlabel .
234+ gdeconstructADT' @_Table @_Columns @f @context @htable @rep fromColumns unnullifier cases
235+
236+
237+type GConstructableADT'
238+ :: (Type -> Exp Constraint)
239+ -> (Type -> Exp K.HTable)
240+ -> (Type -> Exp Type)
241+ -> K.Context -> K.HTable -> (Type -> Type) -> Constraint
242+class GConstructableADT' _Table _Columns f context htable rep where
243+ gbuildADT' :: ()
244+ => ToColumns _Table _Columns f context
245+ -> (Tag -> Nullifier context)
246+ -> htable context
247+ -> GFieldsADT f rep
248+ -> GColumnsADT' _Columns htable rep context
249+
250+ gunbuildADT' :: ()
251+ => FromColumns _Table _Columns f context
252+ -> Unnullifier context
253+ -> GColumnsADT' _Columns htable rep context
254+ -> (htable context, GFieldsADT f rep)
255+
256+ gconstructADT' :: ()
257+ => ToColumns _Table _Columns f context
258+ -> Null context
259+ -> Nullifier context
260+ -> (Tag -> htable context)
261+ -> GConstructors f rep (GColumnsADT' _Columns htable rep context)
262+
263+ gdeconstructADT' :: ()
264+ => FromColumns _Table _Columns f context
265+ -> Unnullifier context
266+ -> GConstructors f rep r
267+ -> GColumnsADT' _Columns htable rep context
268+ -> (htable context, NonEmpty (Tag, r))
269+
270+ gfill :: ()
271+ => Null context
272+ -> htable context
273+ -> GColumnsADT' _Columns htable rep context
274+
275+
276+instance
277+ ( htable' ~ GColumnsADT' _Columns htable a
278+ , Functor (GConstructors f a)
279+ , GConstructableADT' _Table _Columns f context htable a
280+ , GConstructableADT' _Table _Columns f context htable' b
281+ )
282+ => GConstructableADT' _Table _Columns f context htable (a :+: b)
283+ where
284+ gbuildADT' toColumns nullifier htable (a, b) =
285+ gbuildADT' @_Table @_Columns @f @context @htable' @b toColumns nullifier
286+ (gbuildADT' @_Table @_Columns @f @context @htable @a toColumns nullifier htable a)
287+ b
288+
289+ gunbuildADT' fromColumns unnullifier columns =
290+ case gunbuildADT' @_Table @_Columns @f @context @htable' @b fromColumns unnullifier columns of
291+ (htable', b) ->
292+ case gunbuildADT' @_Table @_Columns @f @context @htable @a fromColumns unnullifier htable' of
293+ (htable, a) -> (htable, (a, b))
294+
295+ gconstructADT' toColumns null nullifier mk =
296+ fmap (gfill @_Table @_Columns @f @context @htable' @b null) (gconstructADT' @_Table @_Columns @f @context @htable @a toColumns null nullifier mk) :*:
297+ gconstructADT' @_Table @_Columns @f @context @htable' @b toColumns null nullifier (gfill @_Table @_Columns @f @context @htable @a null . mk)
298+
299+ gdeconstructADT' fromColumns unnullifier (a :*: b) columns =
300+ case gdeconstructADT' @_Table @_Columns @f @context @htable' @b fromColumns unnullifier b columns of
301+ (htable', cases) ->
302+ case gdeconstructADT' @_Table @_Columns @f @context @htable @a fromColumns unnullifier a htable' of
303+ (htable, cases') -> (htable, cases' <> cases)
304+
305+ gfill null =
306+ gfill @_Table @_Columns @f @context @htable' @b null .
307+ gfill @_Table @_Columns @f @context @htable @a null
308+
309+
310+instance (meta ~ 'MetaCons label _fixity _isRecord, KnownSymbol label) =>
311+ GConstructableADT' _Table _Columns f context htable (M1 C meta U1)
312+ where
313+ gbuildADT' _ _ = const
314+ gunbuildADT' _ _ = (, ())
315+ gconstructADT' _ _ _ f _ = f tag
316+ where
317+ tag = Tag $ pack $ symbolVal (Proxy @label)
318+ gdeconstructADT' _ _ r htable = (htable, pure (tag, r ()))
319+ where
320+ tag = Tag $ pack $ symbolVal (Proxy @label)
321+ gfill _ = id
322+
323+
324+instance {-# OVERLAPPABLE #-}
325+ ( HTable (GColumns _Columns rep)
326+ , KnownSymbol label
327+ , meta ~ 'MetaCons label _fixity _isRecord
328+ , GConstructable _Table _Columns f context rep
329+ , GColumnsADT' _Columns htable (M1 C meta rep) ~
330+ HProduct htable (HLabel label (HNullify (GColumns _Columns rep)))
331+ )
332+ => GConstructableADT' _Table _Columns f context htable (M1 C meta rep)
333+ where
334+ gbuildADT' toColumns nullifier htable =
335+ HProduct htable .
336+ hlabel .
337+ hnullify (nullifier tag) .
338+ gconstruct @_Table @_Columns @f @context @rep toColumns
339+ where
340+ tag = Tag $ pack $ symbolVal (Proxy @label)
341+
342+ gunbuildADT' fromColumns unnullifier (HProduct htable a) =
343+ ( htable
344+ , gdeconstruct @_Table @_Columns @f @context @rep fromColumns $
345+ runIdentity $
346+ hunnullify (\spec -> pure . unnullifier spec) $
347+ hunlabel
348+ a
349+ )
350+
351+ gconstructADT' toColumns _ nullifier mk =
352+ HProduct htable .
353+ hlabel .
354+ hnullify nullifier .
355+ gconstruct @_Table @_Columns @f @context @rep toColumns
356+ where
357+ tag = Tag $ pack $ symbolVal (Proxy @label)
358+ htable = mk tag
359+
360+ gdeconstructADT' fromColumns unnullifier r (HProduct htable columns) =
361+ ( htable
362+ , pure (tag, r a)
363+ )
364+ where
365+ a = gdeconstruct @_Table @_Columns @f @context @rep fromColumns $
366+ runIdentity $
367+ hunnullify (\spec -> pure . unnullifier spec) $
368+ hunlabel
369+ columns
370+ tag = Tag $ pack $ symbolVal (Proxy @label)
371+
372+ gfill null htable = HProduct htable (hlabel (hnulls null))
373+
374+
375+type GMakeableADT
376+ :: (Type -> Exp Constraint)
377+ -> (Type -> Exp K.HTable)
378+ -> (Type -> Exp Type)
379+ -> K.Context -> Symbol -> (Type -> Type) -> Constraint
380+class GMakeableADT _Table _Columns f context name rep where
381+ gmakeADT :: ()
382+ => ToColumns _Table _Columns f context
383+ -> Null context
384+ -> Nullifier context
385+ -> (Tag -> HIdentity Tag context)
386+ -> GFields f (GConstructorADT name rep)
387+ -> GColumnsADT _Columns rep context
388+
389+
390+instance
391+ ( htable ~ HLabel "tag" (HIdentity Tag)
392+ , meta ~ 'MetaData datatype _module _package _newtype
393+ , fallback ~ TypeError (NoConstructor datatype name)
394+ , fields ~ GFields f (GConstructorADT' name rep fallback)
395+ , GMakeableADT' _Table _Columns f context htable name rep fields
396+ , KnownSymbol name
397+ )
398+ => GMakeableADT _Table _Columns f context name (M1 D meta rep)
399+ where
400+ gmakeADT toColumns null nullifier wrap =
401+ gmakeADT'
402+ @_Table @_Columns @f @context @htable @name @rep @fields
403+ toColumns null nullifier htable
404+ where
405+ tag = Tag $ pack $ symbolVal (Proxy @name)
406+ htable = hlabel (wrap tag)
407+
408+
409+type GMakeableADT'
410+ :: (Type -> Exp Constraint)
411+ -> (Type -> Exp K.HTable)
412+ -> (Type -> Exp Type)
413+ -> K.Context -> K.HTable -> Symbol -> (Type -> Type) -> Type -> Constraint
414+class GMakeableADT' _Table _Columns f context htable name rep fields where
415+ gmakeADT' :: ()
416+ => ToColumns _Table _Columns f context
417+ -> Null context
418+ -> Nullifier context
419+ -> htable context
420+ -> fields
421+ -> GColumnsADT' _Columns htable rep context
422+
423+
424+instance
425+ ( htable' ~ GColumnsADT' _Columns htable a
426+ , GMakeableADT' _Table _Columns f context htable name a fields
427+ , GMakeableADT' _Table _Columns f context htable' name b fields
428+ )
429+ => GMakeableADT' _Table _Columns f context htable name (a :+: b) fields
430+ where
431+ gmakeADT' toColumns null nullifier htable x =
432+ gmakeADT' @_Table @_Columns @f @context @htable' @name @b @fields
433+ toColumns null nullifier
434+ (gmakeADT'
435+ @_Table @_Columns @f @context @htable @name @a @fields toColumns
436+ null nullifier htable x)
437+ x
438+
439+
440+instance {-# OVERLAPPING #-}
441+ GMakeableADT' _Table _Columns f context htable name (M1 C ('MetaCons name _fixity _isRecord) U1) fields
442+ where
443+ gmakeADT' _ _ _ = const
444+
445+
446+instance {-# OVERLAPS #-}
447+ GMakeableADT' _Table _Columns f context htable name (M1 C ('MetaCons label _fixity _isRecord) U1) fields
448+ where
449+ gmakeADT' _ _ _ = const
450+
451+
452+instance {-# OVERLAPS #-}
453+ ( HTable (GColumns _Columns rep)
454+ , GConstructable _Table _Columns f context rep
455+ , fields ~ GFields f rep
456+ , GColumnsADT' _Columns htable (M1 C ('MetaCons name _fixity _isRecord) rep) ~
457+ HProduct htable (HLabel name (HNullify (GColumns _Columns rep)))
458+ )
459+ => GMakeableADT' _Table _Columns f context htable name (M1 C ('MetaCons name _fixity _isRecord) rep) fields
460+ where
461+ gmakeADT' toColumns _ nullifier htable =
462+ HProduct htable .
463+ hlabel .
464+ hnullify nullifier .
465+ gconstruct @_Table @_Columns @f @context @rep toColumns
466+
467+
468+instance {-# OVERLAPPABLE #-}
469+ ( HTable (GColumns _Columns rep)
470+ , GColumnsADT' _Columns htable (M1 C ('MetaCons label _fixity _isRecord) rep) ~
471+ HProduct htable (HLabel label (HNullify (GColumns _Columns rep)))
472+ )
473+ => GMakeableADT' _Table _Columns f context htable name (M1 C ('MetaCons label _fixity _isRecord) rep) fields
474+ where
475+ gmakeADT' _ null _ htable _ =
476+ HProduct htable $
477+ hlabel $
478+ hnulls null
src/Rel8/Generic/Construction/Record.hsnew file+168
@@ -0,0 +1,168 @@
1+{-# language AllowAmbiguousTypes #-}
2+{-# language BlockArguments #-}
3+{-# language DataKinds #-}
4+{-# language FlexibleInstances #-}
5+{-# language MultiParamTypeClasses #-}
6+{-# language RankNTypes #-}
7+{-# language ScopedTypeVariables #-}
8+{-# language StandaloneKindSignatures #-}
9+{-# language TypeApplications #-}
10+{-# language TypeFamilies #-}
11+{-# language TypeOperators #-}
12+{-# language UndecidableInstances #-}
13+
14+module Rel8.Generic.Construction.Record
15+ ( GConstructor, GConstruct, GConstructable, gconstruct, gdeconstruct
16+ , GFields, Representable, gtabulate, gindex
17+ , FromColumns, ToColumns
18+ )
19+where
20+
21+-- base
22+import Data.Kind ( Constraint, Type )
23+import Data.Proxy ( Proxy( Proxy ) )
24+import GHC.Generics
25+ ( (:*:), K1, M1, U1
26+ , D, C, S, Meta( MetaData, MetaCons, MetaSel )
27+ )
28+import GHC.TypeLits
29+ ( ErrorMessage( (:<>:), Text ), TypeError
30+ , Symbol
31+ )
32+import Prelude
33+
34+-- rel8
35+import Rel8.FCF ( Eval, Exp )
36+import Rel8.Generic.Table.Record ( GColumns )
37+import Rel8.Schema.HTable.Label ( hlabel, hunlabel )
38+import Rel8.Schema.HTable.Product ( HProduct( HProduct ) )
39+import qualified Rel8.Schema.Kind as K
40+
41+
42+type FromColumns
43+ :: (Type -> Exp Constraint)
44+ -> (Type -> Exp K.HTable)
45+ -> (Type -> Exp Type)
46+ -> K.Context
47+ -> Type
48+type FromColumns _Table _Columns f context = forall proxy x.
49+ Eval (_Table x) => proxy x -> Eval (_Columns x) context -> Eval (f x)
50+
51+
52+type ToColumns
53+ :: (Type -> Exp Constraint)
54+ -> (Type -> Exp K.HTable)
55+ -> (Type -> Exp Type)
56+ -> K.Context
57+ -> Type
58+type ToColumns _Table _Columns f context = forall proxy x.
59+ Eval (_Table x) => proxy x -> Eval (f x) -> Eval (_Columns x) context
60+
61+
62+type GConstructor :: (Type -> Type) -> Symbol
63+type family GConstructor rep where
64+ GConstructor (M1 D _ (M1 C ('MetaCons name _ _) _)) = name
65+ GConstructor (M1 D ('MetaData name _ _ _) _) = TypeError (
66+ 'Text "`" ':<>:
67+ 'Text name ':<>:
68+ 'Text "` does not appear to have exactly 1 constructor"
69+ )
70+
71+
72+type GConstruct :: (Type -> Exp Type) -> (Type -> Type) -> Type -> Type
73+type family GConstruct f rep r where
74+ GConstruct f (M1 _ _ rep) r = GConstruct f rep r
75+ GConstruct f (a :*: b) r = GConstruct f a (GConstruct f b r)
76+ GConstruct _ U1 r = r
77+ GConstruct f (K1 _ a) r = Eval (f a) -> r
78+
79+
80+type GFields :: (Type -> Exp Type) -> (Type -> Type) -> Type
81+type family GFields f rep where
82+ GFields f (M1 _ _ rep) = GFields f rep
83+ GFields f (a :*: b) = (GFields f a, GFields f b)
84+ GFields _ U1 = ()
85+ GFields f (K1 _ a) = Eval (f a)
86+
87+
88+type Representable :: (Type -> Exp Type) -> (Type -> Type) -> Constraint
89+class Representable f rep where
90+ gtabulate :: (GFields f rep -> a) -> GConstruct f rep a
91+ gindex :: GConstruct f rep a -> GFields f rep -> a
92+
93+
94+instance Representable f rep => Representable f (M1 i meta rep) where
95+ gtabulate = gtabulate @f @rep
96+ gindex = gindex @f @rep
97+
98+
99+instance (Representable f a, Representable f b) =>
100+ Representable f (a :*: b)
101+ where
102+ gtabulate f = gtabulate @f @a \a -> gtabulate @f @b \b -> f (a, b)
103+ gindex f (a, b) = gindex @f @b (gindex @f @a f a) b
104+
105+
106+instance Representable f U1 where
107+ gtabulate = ($ ())
108+ gindex = const
109+
110+
111+instance Representable f (K1 i a) where
112+ gtabulate = id
113+ gindex = id
114+
115+
116+type GConstructable
117+ :: (Type -> Exp Constraint)
118+ -> (Type -> Exp K.HTable)
119+ -> (Type -> Exp Type)
120+ -> K.Context -> (Type -> Type) -> Constraint
121+class GConstructable _Table _Columns f context rep where
122+ gconstruct :: ()
123+ => ToColumns _Table _Columns f context
124+ -> GFields f rep
125+ -> GColumns _Columns rep context
126+ gdeconstruct :: ()
127+ => FromColumns _Table _Columns f context
128+ -> GColumns _Columns rep context
129+ -> GFields f rep
130+
131+
132+instance (GConstructable _Table _Columns f context rep) =>
133+ GConstructable _Table _Columns f context (M1 D meta rep)
134+ where
135+ gconstruct = gconstruct @_Table @_Columns @f @context @rep
136+ gdeconstruct = gdeconstruct @_Table @_Columns @f @context @rep
137+
138+
139+instance (GConstructable _Table _Columns f context rep) =>
140+ GConstructable _Table _Columns f context (M1 C meta rep)
141+ where
142+ gconstruct = gconstruct @_Table @_Columns @f @context @rep
143+ gdeconstruct = gdeconstruct @_Table @_Columns @f @context @rep
144+
145+
146+instance
147+ ( GConstructable _Table _Columns f context a
148+ , GConstructable _Table _Columns f context b
149+ )
150+ => GConstructable _Table _Columns f context (a :*: b)
151+ where
152+ gconstruct toColumns (a, b) = HProduct
153+ (gconstruct @_Table @_Columns @f @context @a toColumns a)
154+ (gconstruct @_Table @_Columns @f @context @b toColumns b)
155+ gdeconstruct fromColumns (HProduct a b) =
156+ ( gdeconstruct @_Table @_Columns @f @context @a fromColumns a
157+ , gdeconstruct @_Table @_Columns @f @context @b fromColumns b
158+ )
159+
160+
161+instance
162+ ( Eval (_Table a)
163+ , meta ~ 'MetaSel ('Just label) _su _ss _ds
164+ )
165+ => GConstructable _Table _Columns f context (M1 S meta (K1 i a))
166+ where
167+ gconstruct toColumns = hlabel . toColumns (Proxy @a)
168+ gdeconstruct fromColumns = fromColumns (Proxy @a) . hunlabel
src/Rel8/Generic/Map.hsnew file+49
@@ -0,0 +1,49 @@
1+{-# language DataKinds #-}
2+{-# language StandaloneKindSignatures #-}
3+{-# language TypeFamilies #-}
4+{-# language TypeOperators #-}
5+{-# language UndecidableInstances #-}
6+
7+module Rel8.Generic.Map
8+ ( GMap
9+ , Map
10+ )
11+where
12+
13+-- base
14+import Data.Kind ( Type )
15+import GHC.Generics
16+ ( (:+:), (:*:), K1, M1, U1, V1
17+ )
18+import Prelude ()
19+
20+-- rel8
21+import Rel8.FCF ( Eval, Exp )
22+
23+
24+type GMap :: (Type -> Exp Type) -> (Type -> Type) -> Type -> Type
25+type family GMap f rep where
26+ GMap f (M1 i c rep) = M1 i c (GMap f rep)
27+ GMap _ V1 = V1
28+ GMap f (rep1 :+: rep2) = GMap f rep1 :+: GMap f rep2
29+ GMap _ U1 = U1
30+ GMap f (rep1 :*: rep2) = GMap f rep1 :*: GMap f rep2
31+ GMap f (K1 i a) = K1 i (Eval (f a))
32+
33+
34+-- | Map a @Type -> Type@ function over the @Type@-kinded type variables in
35+-- of a type constructor.
36+type Map :: (Type -> Exp Type) -> Type -> Type
37+type family Map f a where
38+ Map p (t a b c d e f g) =
39+ t (Eval (p a)) (Eval (p b)) (Eval (p c)) (Eval (p d)) (Eval (p e))
40+ (Eval (p f)) (Eval (p g))
41+ Map p (t a b c d e f) =
42+ t (Eval (p a)) (Eval (p b)) (Eval (p c)) (Eval (p d)) (Eval (p e))
43+ (Eval (p f))
44+ Map p (t a b c d e) =
45+ t (Eval (p a)) (Eval (p b)) (Eval (p c)) (Eval (p d)) (Eval (p e))
46+ Map p (t a b c d) = t (Eval (p a)) (Eval (p b)) (Eval (p c)) (Eval (p d))
47+ Map p (t a b c) = t (Eval (p a)) (Eval (p b)) (Eval (p c))
48+ Map p (t a b) = t (Eval (p a)) (Eval (p b))
49+ Map p (t a) = t (Eval (p a))
src/Rel8/Generic/Record.hsnew file+155
@@ -0,0 +1,155 @@
1+{-# language AllowAmbiguousTypes #-}
2+{-# language DataKinds #-}
3+{-# language FlexibleContexts #-}
4+{-# language FlexibleInstances #-}
5+{-# language MultiParamTypeClasses #-}
6+{-# language PolyKinds #-}
7+{-# language ScopedTypeVariables #-}
8+{-# language StandaloneKindSignatures #-}
9+{-# language TypeApplications #-}
10+{-# language TypeFamilies #-}
11+{-# language TypeOperators #-}
12+{-# language UndecidableInstances #-}
13+
14+module Rel8.Generic.Record
15+ ( Record(..)
16+ , GRecordable, GRecord, grecord, gunrecord
17+ )
18+where
19+
20+-- base
21+import Data.Kind ( Constraint, Type )
22+import GHC.Generics
23+ ( Generic, Rep, from, to
24+ , (:+:)( L1, R1 ), (:*:)( (:*:) ), M1( M1 )
25+ , Meta( MetaCons, MetaSel ), D, C, S
26+ )
27+import GHC.TypeLits ( type (+), AppendSymbol, Div, Mod, Nat, Symbol )
28+import Prelude hiding ( Show )
29+
30+
31+type GRecord :: (Type -> Type) -> Type -> Type
32+type family GRecord rep where
33+ GRecord (M1 D meta rep) = M1 D meta (GRecord rep)
34+ GRecord (l :+: r) = GRecord l :+: GRecord r
35+ GRecord (M1 C ('MetaCons name fixity 'False) rep) =
36+ M1 C ('MetaCons name fixity 'True) (Snd (Count 0 rep))
37+ GRecord rep = rep
38+
39+
40+type Count :: Nat -> (Type -> Type) -> (Nat, Type -> Type)
41+type family Count n rep where
42+ Count n (M1 S ('MetaSel _selector su ss ds) rep) =
43+ '(n + 1, M1 S ('MetaSel ('Just (Show (n + 1))) su ss ds) rep)
44+ Count n (a :*: b) = CountHelper1 (Count n a) b
45+ Count n rep = '(n, rep)
46+
47+
48+type CountHelper1 :: (Nat, Type -> Type) -> (Type -> Type) -> (Nat, Type -> Type)
49+type family CountHelper1 tuple b where
50+ CountHelper1 '(n, a) b = CountHelper2 a (Count n b)
51+
52+
53+type CountHelper2 :: (Type -> Type) -> (Nat, Type -> Type) -> (Nat, Type -> Type)
54+type family CountHelper2 a tuple where
55+ CountHelper2 a '(n, b) = '(n, a :*: b)
56+
57+
58+type Show :: Nat -> Symbol
59+type Show n =
60+ AppendSymbol "_" (AppendSymbol (Show' (Div n 10)) (ShowDigit (Mod n 10)))
61+
62+
63+type Show' :: Nat -> Symbol
64+type family Show' n where
65+ Show' 0 = ""
66+ Show' n = AppendSymbol (Show' (Div n 10)) (ShowDigit (Mod n 10))
67+
68+
69+type ShowDigit :: Nat -> Symbol
70+type family ShowDigit n where
71+ ShowDigit 0 = "0"
72+ ShowDigit 1 = "1"
73+ ShowDigit 2 = "2"
74+ ShowDigit 3 = "3"
75+ ShowDigit 4 = "4"
76+ ShowDigit 5 = "5"
77+ ShowDigit 6 = "6"
78+ ShowDigit 7 = "7"
79+ ShowDigit 8 = "8"
80+ ShowDigit 9 = "9"
81+
82+
83+type Snd :: (a, b) -> b
84+type family Snd tuple where
85+ Snd '(_a, b) = b
86+
87+
88+type GRecordable :: (Type -> Type) -> Constraint
89+class GRecordable rep where
90+ grecord :: rep x -> GRecord rep x
91+ gunrecord :: GRecord rep x -> rep x
92+
93+
94+instance GRecordable rep => GRecordable (M1 D meta rep) where
95+ grecord (M1 a) = M1 (grecord a)
96+ gunrecord (M1 a) = M1 (gunrecord a)
97+
98+
99+instance (GRecordable l, GRecordable r) => GRecordable (l :+: r) where
100+ grecord (L1 a) = L1 (grecord a)
101+ grecord (R1 a) = R1 (grecord a)
102+ gunrecord (L1 a) = L1 (gunrecord a)
103+ gunrecord (R1 a) = R1 (gunrecord a)
104+
105+
106+instance Countable 0 rep =>
107+ GRecordable (M1 C ('MetaCons name fixity 'False) rep)
108+ where
109+ grecord (M1 a) = M1 (count @0 a)
110+ gunrecord (M1 a) = M1 (uncount @0 a)
111+
112+
113+instance {-# OVERLAPPABLE #-} GRecord rep ~ rep => GRecordable rep where
114+ grecord = id
115+ gunrecord = id
116+
117+
118+type Countable :: Nat -> (Type -> Type) -> Constraint
119+class Countable n rep where
120+ count :: rep x -> Snd (Count n rep) x
121+ uncount :: Snd (Count n rep) x -> rep x
122+
123+
124+instance Countable n (M1 S ('MetaSel selector su ss ds) rep) where
125+ count (M1 a) = M1 a
126+ uncount (M1 a) = M1 a
127+
128+
129+instance
130+ ( Countable n a, Countable n' b
131+ , '(n', a') ~ Count n a
132+ , Snd (CountHelper2 a' (Count n' b)) ~ (a' :*: Snd (Count n' b))
133+ )
134+ => Countable n (a :*: b)
135+ where
136+ count (a :*: b) = count @n a :*: count @n' b
137+ uncount (a :*: b) = uncount @n a :*: uncount @n' b
138+
139+
140+instance {-# OVERLAPPABLE #-} Snd (Count n rep) ~ rep => Countable n rep where
141+ count = id
142+ uncount = id
143+
144+
145+type Record :: Type -> Type
146+newtype Record a = Record
147+ { unrecord :: a
148+ }
149+
150+
151+instance (Generic a, GRecordable (Rep a)) => Generic (Record a) where
152+ type Rep (Record a) = GRecord (Rep a)
153+
154+ from (Record a) = grecord (from a)
155+ to = Record . to . gunrecord
src/Rel8/Generic/Rel8able.hsnew file+281
@@ -0,0 +1,281 @@
1+{-# language AllowAmbiguousTypes #-}
2+{-# language ConstraintKinds #-}
3+{-# language DataKinds #-}
4+{-# language DefaultSignatures #-}
5+{-# language FlexibleContexts #-}
6+{-# language FlexibleInstances #-}
7+{-# language LambdaCase #-}
8+{-# language MultiParamTypeClasses #-}
9+{-# language PolyKinds #-}
10+{-# language QuantifiedConstraints #-}
11+{-# language ScopedTypeVariables #-}
12+{-# language StandaloneKindSignatures #-}
13+{-# language TypeApplications #-}
14+{-# language TypeFamilyDependencies #-}
15+{-# language TypeOperators #-}
16+{-# language UndecidableInstances #-}
17+
18+module Rel8.Generic.Rel8able
19+ ( KRel8able, Rel8able
20+ , Algebra
21+ , GRep
22+ , GColumns, gfromColumns, gtoColumns
23+ , GFromExprs, gfromResult, gtoResult
24+ , TSerialize, serialize, deserialize
25+ )
26+where
27+
28+-- base
29+import Data.Functor.Identity ( Identity )
30+import Data.Kind ( Constraint, Type )
31+import Data.Type.Bool ( type (&&) )
32+import GHC.Generics ( Generic, Rep, from, to )
33+import Prelude
34+
35+-- rel8
36+import Rel8.Aggregate ( Aggregate )
37+import Rel8.Expr ( Expr )
38+import Rel8.FCF ( Exp, Eval )
39+import Rel8.Generic.Record ( Record(..) )
40+import Rel8.Generic.Table ( GAlgebra )
41+import qualified Rel8.Generic.Table.Record as G
42+import qualified Rel8.Kind.Algebra as K ( Algebra(..) )
43+import Rel8.Kind.Context ( SContext(..) )
44+import Rel8.Schema.Field ( Field )
45+import Rel8.Schema.HTable ( HTable )
46+import qualified Rel8.Schema.Kind as K
47+import Rel8.Schema.Name ( Name )
48+import Rel8.Schema.Result ( Result )
49+import Rel8.Table
50+ ( Table, Columns, Context, fromColumns, toColumns
51+ , FromExprs, fromResult, toResult
52+ , Transpose
53+ , TTable, TColumns
54+ )
55+import Rel8.Table.Transpose ( Transposes )
56+
57+
58+-- | The kind of 'Rel8able' types
59+type KRel8able :: Type
60+type KRel8able = K.Rel8able
61+
62+
63+-- This is almost 'Data.Type.Equality.==', but we add an extra case.
64+type (==) :: k -> k -> Bool
65+type family a == b where
66+ -- This extra case is needed to solve the equation "a == a" (where a is a
67+ -- KRel8able), which occurs when we have polymorphic Rel8ables
68+ -- (e.g., newtype T t f = T { x :: t a })
69+ (a :: KRel8able) == (a :: KRel8able) = 'True
70+
71+ -- This extra case is needed to solve the equation "a == Identity a",
72+ -- which occurs when we have polymorphic Rel8ables
73+ -- (e.g., newtype T a f = T { x :: Column f a })
74+ a == Identity a = 'False
75+
76+ -- These cases are exactly the same as those in 'Data.Type.Equality.==.
77+ f a == g b = f == g && a == b
78+ a == a = 'True
79+ _ == _ = 'False
80+
81+
82+type Serialize :: Bool -> Type -> Type -> Constraint
83+class transposition ~ (a == Transpose Result expr) =>
84+ Serialize transposition expr a
85+ where
86+ serialize :: a -> Columns expr Result
87+ deserialize :: Columns expr Result -> a
88+
89+
90+instance
91+ ( (a == Transpose Result expr) ~ 'True
92+ , Transposes Expr Result expr a
93+ )
94+ => Serialize 'True expr a
95+ where
96+ serialize = toColumns
97+ deserialize = fromColumns
98+
99+
100+instance
101+ ( (a == Transpose Result expr) ~ 'False
102+ , Table (Context expr) expr
103+ , FromExprs expr ~ a
104+ )
105+ => Serialize 'False expr a
106+ where
107+ serialize = toResult @_ @expr
108+ deserialize = fromResult @_ @expr
109+
110+
111+data TSerialize :: Type -> Type -> Exp Constraint
112+type instance Eval (TSerialize expr a) =
113+ Serialize (a == Transpose Result expr) expr a
114+
115+
116+-- | This type class allows you to define custom 'Table's using higher-kinded
117+-- data types. Higher-kinded data types are data types of the pattern:
118+--
119+-- @
120+-- data MyType f =
121+-- MyType { field1 :: Column f T1 OR HK1 f
122+-- , field2 :: Column f T2 OR HK2 f
123+-- , ...
124+-- , fieldN :: Column f Tn OR HKn f
125+-- }
126+-- @
127+--
128+-- where @Tn@ is any Haskell type, and @HKn@ is any higher-kinded type.
129+--
130+-- That is, higher-kinded data are records where all fields in the record are
131+-- all either of the type @Column f T@ (for any @T@), or are themselves
132+-- higher-kinded data:
133+--
134+-- [Nested]
135+--
136+-- @
137+-- data Nested f =
138+-- Nested { nested1 :: MyType f
139+-- , nested2 :: MyType f
140+-- }
141+-- @
142+--
143+-- The @Rel8able@ type class is used to give us a special mapping operation
144+-- that lets us change the type parameter @f@.
145+--
146+-- [Supplying @Rel8able@ instances]
147+--
148+-- This type class should be derived generically for all table types in your
149+-- project. To do this, enable the @DeriveAnyClass@ and @DeriveGeneric@ language
150+-- extensions:
151+--
152+-- @
153+-- \{\-\# LANGUAGE DeriveAnyClass, DeriveGeneric #-\}
154+--
155+-- data MyType f = MyType { fieldA :: Column f T }
156+-- deriving ( GHC.Generics.Generic, Rel8able )
157+-- @
158+type Rel8able :: K.Rel8able -> Constraint
159+class HTable (GColumns t) => Rel8able t where
160+ type GColumns t :: K.HTable
161+ type GFromExprs t :: Type
162+
163+ gfromColumns :: SContext context -> GColumns t context -> t context
164+ gtoColumns :: SContext context -> t context -> GColumns t context
165+
166+ gfromResult :: GColumns t Result -> GFromExprs t
167+ gtoResult :: GFromExprs t -> GColumns t Result
168+
169+ type GColumns t = G.GColumns TColumns (GRep t Expr)
170+ type GFromExprs t = t Result
171+
172+ default gfromColumns :: forall context.
173+ ( SRel8able t Aggregate
174+ , SRel8able t Expr
175+ , forall table. SRel8able t (Field table)
176+ , SRel8able t Name
177+ , SSerialize t
178+ )
179+ => SContext context -> GColumns t context -> t context
180+ gfromColumns = \case
181+ SAggregate -> sfromColumns
182+ SExpr -> sfromColumns
183+ SField -> sfromColumns
184+ SName -> sfromColumns
185+ SResult -> sfromResult
186+
187+ default gtoColumns :: forall context.
188+ ( SRel8able t Aggregate
189+ , SRel8able t Expr
190+ , forall table. SRel8able t (Field table)
191+ , SRel8able t Name
192+ , SSerialize t
193+ )
194+ => SContext context -> t context -> GColumns t context
195+ gtoColumns = \case
196+ SAggregate -> stoColumns
197+ SExpr -> stoColumns
198+ SField -> stoColumns
199+ SName -> stoColumns
200+ SResult -> stoResult
201+
202+ default gfromResult :: (SSerialize t, GFromExprs t ~ t Result)
203+ => GColumns t Result -> GFromExprs t
204+ gfromResult = sfromResult
205+
206+ default gtoResult :: (SSerialize t, GFromExprs t ~ t Result)
207+ => GFromExprs t -> GColumns t Result
208+ gtoResult = stoResult
209+
210+
211+type Algebra :: K.Rel8able -> K.Algebra
212+type Algebra t = GAlgebra (GRep t Expr)
213+
214+
215+type GRep :: K.Rel8able -> K.Context -> Type -> Type
216+type GRep t context = Rep (Record (t context))
217+
218+
219+type SRel8able :: K.Rel8able -> K.Context -> Constraint
220+class
221+ ( Generic (Record (t context))
222+ , G.GTable (TTable context) TColumns (GRep t context)
223+ , G.GColumns TColumns (GRep t context) ~ GColumns t
224+ )
225+ => SRel8able t context
226+instance
227+ ( Generic (Record (t context))
228+ , G.GTable (TTable context) TColumns (GRep t context)
229+ , G.GColumns TColumns (GRep t context) ~ GColumns t
230+ )
231+ => SRel8able t context
232+
233+
234+type SSerialize :: K.Rel8able -> Constraint
235+type SSerialize t =
236+ ( Generic (Record (t Result))
237+ , G.GSerialize TSerialize TColumns (GRep t Expr) (GRep t Result)
238+ , G.GColumns TColumns (GRep t Expr) ~ GColumns t
239+ )
240+
241+
242+sfromColumns :: forall t context. SRel8able t context
243+ => GColumns t context -> t context
244+sfromColumns =
245+ unrecord .
246+ to .
247+ G.gfromColumns @(TTable context) @TColumns fromColumns
248+
249+
250+stoColumns :: forall t context. SRel8able t context
251+ => t context -> GColumns t context
252+stoColumns =
253+ G.gtoColumns @(TTable context) @TColumns toColumns .
254+ from .
255+ Record
256+
257+
258+sfromResult :: forall t. SSerialize t
259+ => GColumns t Result -> t Result
260+sfromResult =
261+ unrecord .
262+ to .
263+ G.gfromResult
264+ @TSerialize
265+ @TColumns
266+ @(GRep t Expr)
267+ @(GRep t Result)
268+ (\(_ :: proxy x) -> deserialize @_ @x)
269+
270+
271+stoResult :: forall t. SSerialize t
272+ => t Result -> GColumns t Result
273+stoResult =
274+ G.gtoResult
275+ @TSerialize
276+ @TColumns
277+ @(GRep t Expr)
278+ @(GRep t Result)
279+ (\(_ :: proxy x) -> serialize @_ @x) .
280+ from .
281+ Record
src/Rel8/Generic/Table.hsnew file+103
@@ -0,0 +1,103 @@
1+{-# language AllowAmbiguousTypes #-}
2+{-# language DataKinds #-}
3+{-# language FlexibleContexts #-}
4+{-# language FlexibleInstances #-}
5+{-# language MultiParamTypeClasses #-}
6+{-# language RankNTypes #-}
7+{-# language ScopedTypeVariables #-}
8+{-# language StandaloneKindSignatures #-}
9+{-# language TypeApplications #-}
10+{-# language TypeFamilies #-}
11+{-# language TypeOperators #-}
12+{-# language UndecidableInstances #-}
13+
14+module Rel8.Generic.Table
15+ ( GGSerialize, GGColumns, ggfromResult, ggtoResult
16+ , GAlgebra
17+ )
18+where
19+
20+-- base
21+import Data.Kind ( Constraint, Type )
22+import GHC.Generics ( (:+:), (:*:), K1, M1, U1, V1 )
23+import Prelude ()
24+
25+-- rel8
26+import Rel8.FCF ( Eval, Exp )
27+import Rel8.Generic.Table.ADT
28+ ( GSerializeADT, GColumnsADT, gtoResultADT, gfromResultADT
29+ )
30+import Rel8.Generic.Table.Record ( GSerialize, GColumns, gtoResult, gfromResult )
31+import Rel8.Kind.Algebra
32+ ( Algebra( Product, Sum )
33+ , SAlgebra( SProduct, SSum )
34+ , KnownAlgebra, algebraSing
35+ )
36+import qualified Rel8.Schema.Kind as K
37+import Rel8.Schema.Result ( Result )
38+
39+
40+data GGSerialize
41+ :: Algebra
42+ -> (Type -> Type -> Exp Constraint)
43+ -> (Type -> Exp K.HTable)
44+ -> (Type -> Type)
45+ -> (Type -> Type)
46+ -> Exp Constraint
47+
48+
49+type instance Eval (GGSerialize 'Product _Serialize _Columns exprs rep) =
50+ GSerialize _Serialize _Columns exprs rep
51+
52+
53+type instance Eval (GGSerialize 'Sum _Serialize _Columns exprs rep) =
54+ GSerializeADT _Serialize _Columns exprs rep
55+
56+
57+data GGColumns
58+ :: Algebra
59+ -> (Type -> Exp K.HTable)
60+ -> (Type -> Type)
61+ -> Exp K.HTable
62+
63+
64+type instance Eval (GGColumns 'Product _Columns rep) = GColumns _Columns rep
65+
66+
67+type instance Eval (GGColumns 'Sum _Columns rep) = GColumnsADT _Columns rep
68+
69+
70+type GAlgebra :: (Type -> Type) -> Algebra
71+type family GAlgebra rep where
72+ GAlgebra (M1 _ _ rep) = GAlgebra rep
73+ GAlgebra V1 = 'Sum
74+ GAlgebra (_ :+: _) = 'Sum
75+ GAlgebra U1 = 'Sum
76+ GAlgebra (_ :*: _) = 'Product
77+ GAlgebra (K1 _ _) = 'Product
78+
79+
80+ggfromResult :: forall algebra _Serialize _Columns exprs rep x.
81+ ( KnownAlgebra algebra
82+ , Eval (GGSerialize algebra _Serialize _Columns exprs rep)
83+ )
84+ => (forall expr a proxy. Eval (_Serialize expr a)
85+ => proxy expr -> Eval (_Columns expr) Result -> a)
86+ -> Eval (GGColumns algebra _Columns exprs) Result
87+ -> rep x
88+ggfromResult f x = case algebraSing @algebra of
89+ SProduct -> gfromResult @_Serialize @_Columns @exprs @rep f x
90+ SSum -> gfromResultADT @_Serialize @_Columns @exprs @rep f x
91+
92+
93+ggtoResult :: forall algebra _Serialize _Columns exprs rep x.
94+ ( KnownAlgebra algebra
95+ , Eval (GGSerialize algebra _Serialize _Columns exprs rep)
96+ )
97+ => (forall expr a proxy. Eval (_Serialize expr a)
98+ => proxy expr -> a -> Eval (_Columns expr) Result)
99+ -> rep x
100+ -> Eval (GGColumns algebra _Columns exprs) Result
101+ggtoResult f x = case algebraSing @algebra of
102+ SProduct -> gtoResult @_Serialize @_Columns @exprs @rep f x
103+ SSum -> gtoResultADT @_Serialize @_Columns @exprs @rep f x
src/Rel8/Generic/Table/ADT.hsnew file+221
@@ -0,0 +1,221 @@
1+{-# language AllowAmbiguousTypes #-}
2+{-# language DataKinds #-}
3+{-# language FlexibleContexts #-}
4+{-# language FlexibleInstances #-}
5+{-# language LambdaCase #-}
6+{-# language MultiParamTypeClasses #-}
7+{-# language RankNTypes #-}
8+{-# language ScopedTypeVariables #-}
9+{-# language StandaloneKindSignatures #-}
10+{-# language TypeApplications #-}
11+{-# language TypeFamilies #-}
12+{-# language TypeOperators #-}
13+{-# language UndecidableInstances #-}
14+
15+module Rel8.Generic.Table.ADT
16+ ( GSerializeADT, GColumnsADT, gfromResultADT, gtoResultADT
17+ , GSerializeADT', GColumnsADT'
18+ )
19+where
20+
21+-- base
22+import Data.Functor.Identity ( Identity( Identity ) )
23+import Data.Kind ( Constraint, Type )
24+import Data.Proxy ( Proxy( Proxy ) )
25+import GHC.Generics
26+ ( (:+:)( L1, R1 ), M1( M1 ), U1( U1 )
27+ , C, D
28+ , Meta( MetaCons )
29+ )
30+import GHC.TypeLits ( KnownSymbol, symbolVal )
31+import Prelude hiding ( null )
32+
33+-- rel8
34+import Rel8.FCF ( Eval, Exp )
35+import Rel8.Generic.Table.Record ( GSerialize, GColumns, gfromResult, gtoResult )
36+import Rel8.Schema.HTable ( HTable )
37+import Rel8.Schema.HTable.Identity ( HIdentity( HIdentity ) )
38+import Rel8.Schema.HTable.Label ( HLabel, hlabel, hunlabel )
39+import Rel8.Schema.HTable.Nullify ( HNullify, hnulls, hnullify, hunnullify )
40+import Rel8.Schema.HTable.Product ( HProduct( HProduct ) )
41+import qualified Rel8.Schema.Kind as K
42+import Rel8.Schema.Result ( Result, null, nullifier, unnullifier )
43+import Rel8.Type.Tag ( Tag( Tag ) )
44+
45+-- text
46+import Data.Text ( pack )
47+
48+
49+type GColumnsADT
50+ :: (Type -> Exp K.HTable)
51+ -> (Type -> Type) -> K.HTable
52+type family GColumnsADT _Columns rep where
53+ GColumnsADT _Columns (M1 D _ rep) =
54+ GColumnsADT' _Columns (HLabel "tag" (HIdentity Tag)) rep
55+
56+
57+type GColumnsADT'
58+ :: (Type -> Exp K.HTable)
59+ -> K.HTable -> (Type -> Type) -> K.HTable
60+type family GColumnsADT' _Columns htable rep where
61+ GColumnsADT' _Columns htable (a :+: b) =
62+ GColumnsADT' _Columns (GColumnsADT' _Columns htable a) b
63+ GColumnsADT' _Columns htable (M1 C ('MetaCons _ _ _) U1) = htable
64+ GColumnsADT' _Columns htable (M1 C ('MetaCons label _ _) rep) =
65+ HProduct htable (HLabel label (HNullify (GColumns _Columns rep)))
66+
67+
68+type GSerializeADT
69+ :: (Type -> Type -> Exp Constraint)
70+ -> (Type -> Exp K.HTable)
71+ -> (Type -> Type) -> (Type -> Type) -> Constraint
72+class GSerializeADT _Serialize _Columns exprs rep where
73+ gfromResultADT :: ()
74+ => (forall expr a proxy. Eval (_Serialize expr a)
75+ => proxy expr -> Eval (_Columns expr) Result -> a)
76+ -> GColumnsADT _Columns exprs Result
77+ -> rep x
78+
79+ gtoResultADT :: ()
80+ => (forall expr a proxy. Eval (_Serialize expr a)
81+ => proxy expr -> a -> Eval (_Columns expr) Result)
82+ -> rep x
83+ -> GColumnsADT _Columns exprs Result
84+
85+
86+instance
87+ ( htable ~ HLabel "tag" (HIdentity Tag)
88+ , GSerializeADT' _Serialize _Columns htable exprs rep
89+ )
90+ => GSerializeADT _Serialize _Columns (M1 D meta exprs) (M1 D meta rep)
91+ where
92+ gfromResultADT fromResult columns =
93+ case gfromResultADT' @_Serialize @_Columns @htable @exprs @rep fromResult tag columns of
94+ Just rep -> M1 rep
95+ _ -> error "ADT.fromColumns: mismatch between tag and data"
96+ where
97+ tag = (\(HIdentity (Identity a)) -> a) . hunlabel @"tag"
98+
99+ gtoResultADT toResult (M1 rep) =
100+ gtoResultADT' @_Serialize @_Columns @htable @exprs @rep toResult tag (Just rep)
101+ where
102+ tag = hlabel @"tag" . HIdentity . Identity
103+
104+
105+type GSerializeADT'
106+ :: (Type -> Type -> Exp Constraint)
107+ -> (Type -> Exp K.HTable)
108+ -> K.HTable -> (Type -> Type) -> (Type -> Type) -> Constraint
109+class GSerializeADT' _Serialize _Columns htable exprs rep where
110+ gfromResultADT' :: context ~ Result
111+ => (forall expr a proxy. Eval (_Serialize expr a)
112+ => proxy expr -> Eval (_Columns expr) context -> a)
113+ -> (htable Result -> Tag)
114+ -> GColumnsADT' _Columns htable exprs context
115+ -> Maybe (rep x)
116+
117+ gtoResultADT' :: context ~ Result
118+ => (forall expr a proxy. Eval (_Serialize expr a)
119+ => proxy expr -> a -> Eval (_Columns expr) context)
120+ -> (Tag -> htable Result)
121+ -> Maybe (rep x)
122+ -> GColumnsADT' _Columns htable exprs context
123+
124+ extract :: GColumnsADT' _Columns htable exprs context -> htable context
125+
126+
127+instance
128+ ( htable' ~ GColumnsADT' _Columns htable exprs1
129+ , GSerializeADT' _Serialize _Columns htable exprs1 a
130+ , GSerializeADT' _Serialize _Columns htable' exprs2 b
131+ )
132+ => GSerializeADT' _Serialize _Columns htable (exprs1 :+: exprs2) (a :+: b)
133+ where
134+ gfromResultADT' fromResult f columns =
135+ case ma of
136+ Just a -> Just (L1 a)
137+ Nothing -> R1 <$>
138+ gfromResultADT' @_Serialize @_Columns @_ @exprs2 @b
139+ fromResult
140+ (f . extract @_Serialize @_Columns @_ @exprs1 @a)
141+ columns
142+ where
143+ ma =
144+ gfromResultADT' @_Serialize @_Columns @_ @exprs1 @a
145+ fromResult
146+ f
147+ (extract @_Serialize @_Columns @_ @exprs2 @b columns)
148+
149+ gtoResultADT' toResult tag = \case
150+ Just (L1 a) ->
151+ gtoResultADT' @_Serialize @_Columns @_ @exprs2 @b
152+ toResult
153+ (\_ -> gtoResultADT' @_Serialize @_Columns @_ @exprs1 @a
154+ toResult
155+ tag
156+ (Just a))
157+ Nothing
158+ Just (R1 b) ->
159+ gtoResultADT' @_Serialize @_Columns @_ @exprs2 @b
160+ toResult
161+ (\tag' ->
162+ gtoResultADT' @_Serialize @_Columns @_ @exprs1 @a
163+ toResult
164+ (\_ -> tag tag')
165+ Nothing)
166+ (Just b)
167+ Nothing ->
168+ gtoResultADT' @_Serialize @_Columns @_ @exprs2 @b
169+ toResult
170+ (\_ -> gtoResultADT' @_Serialize @_Columns @_ @exprs1 @a toResult tag Nothing)
171+ Nothing
172+
173+ extract =
174+ extract @_Serialize @_Columns @_ @exprs1 @a .
175+ extract @_Serialize @_Columns @_ @exprs2 @b
176+
177+
178+instance (meta ~ 'MetaCons label _fixity _isRecord, KnownSymbol label) =>
179+ GSerializeADT' _Serialize _Columns _htable (M1 C meta U1) (M1 C meta U1)
180+ where
181+ gfromResultADT' _ tag columns
182+ | tag columns == tag' = Just (M1 U1)
183+ | otherwise = Nothing
184+ where
185+ tag' = Tag $ pack $ symbolVal (Proxy @label)
186+
187+ gtoResultADT' _ tag _ = tag tag'
188+ where
189+ tag' = Tag $ pack $ symbolVal (Proxy @label)
190+
191+ extract = id
192+
193+
194+instance {-# OVERLAPPABLE #-}
195+ ( HTable (GColumns _Columns exprs)
196+ , GSerialize _Serialize _Columns exprs rep
197+ , meta ~ 'MetaCons label _fixity _isRecord
198+ , KnownSymbol label
199+ , GColumnsADT' _Columns htable (M1 C ('MetaCons label _fixity _isRecord) exprs) ~
200+ HProduct htable (HLabel label (HNullify (GColumns _Columns exprs)))
201+ )
202+ => GSerializeADT' _Serialize _Columns htable (M1 C meta exprs) (M1 C meta rep)
203+ where
204+ gfromResultADT' fromResult tag (HProduct a b)
205+ | tag a == tag' =
206+ M1 . gfromResult @_Serialize @_Columns @exprs @rep fromResult <$>
207+ hunnullify unnullifier (hunlabel b)
208+ | otherwise = Nothing
209+ where
210+ tag' = Tag $ pack $ symbolVal (Proxy @label)
211+
212+ gtoResultADT' toResult tag = \case
213+ Nothing -> HProduct (tag tag') (hlabel (hnulls (const null)))
214+ Just (M1 rep) -> HProduct (tag tag') $
215+ hlabel $
216+ hnullify nullifier $
217+ gtoResult @_Serialize @_Columns @exprs @rep toResult rep
218+ where
219+ tag' = Tag $ pack $ symbolVal (Proxy @label)
220+
221+ extract (HProduct a _) = a
src/Rel8/Generic/Table/Record.hsnew file+181
@@ -0,0 +1,181 @@
1+{-# language AllowAmbiguousTypes #-}
2+{-# language DataKinds #-}
3+{-# language FlexibleContexts #-}
4+{-# language FlexibleInstances #-}
5+{-# language MultiParamTypeClasses #-}
6+{-# language PolyKinds #-}
7+{-# language RankNTypes #-}
8+{-# language ScopedTypeVariables #-}
9+{-# language StandaloneKindSignatures #-}
10+{-# language TypeApplications #-}
11+{-# language TypeFamilies #-}
12+{-# language TypeOperators #-}
13+{-# language UndecidableInstances #-}
14+
15+module Rel8.Generic.Table.Record
16+ ( GTable, GColumns, GContext, gfromColumns, gtoColumns, gtable
17+ , GSerialize, gfromResult, gtoResult
18+ )
19+where
20+
21+-- base
22+import Data.Kind ( Constraint, Type )
23+import Data.Proxy ( Proxy( Proxy ) )
24+import GHC.Generics
25+ ( (:*:)( (:*:) ), K1( K1 ), M1( M1 )
26+ , C, D, S
27+ , Meta( MetaSel )
28+ )
29+import Prelude hiding ( null )
30+
31+-- rel8
32+import Rel8.FCF ( Eval, Exp )
33+import Rel8.Schema.HTable.Label ( HLabel, hlabel, hunlabel )
34+import Rel8.Schema.HTable.Product ( HProduct(..) )
35+import qualified Rel8.Schema.Kind as K
36+
37+
38+type GColumns :: (Type -> Exp K.HTable) -> (Type -> Type) -> K.HTable
39+type family GColumns _Columns rep where
40+ GColumns _Columns (M1 D _ rep) = GColumns _Columns rep
41+ GColumns _Columns (M1 C _ rep) = GColumns _Columns rep
42+ GColumns _Columns (rep1 :*: rep2) =
43+ HProduct (GColumns _Columns rep1) (GColumns _Columns rep2)
44+ GColumns _Columns (M1 S ('MetaSel ('Just label) _ _ _) (K1 _ a)) =
45+ HLabel label (Eval (_Columns a))
46+
47+
48+type GContext :: (Type -> Exp K.Context) -> (Type -> Type) -> K.Context
49+type family GContext _Context rep where
50+ GContext _Context (M1 _ _ rep) = GContext _Context rep
51+ GContext _Context (rep1 :*: _rep2) = GContext _Context rep1
52+ GContext _Context (K1 _ a) = Eval (_Context a)
53+
54+
55+type GTable
56+ :: (Type -> Exp Constraint)
57+ -> (Type -> Exp K.HTable)
58+ -> (Type -> Type) -> Constraint
59+class GTable _Table _Columns rep
60+ where
61+ gfromColumns :: ()
62+ => (forall a. Eval (_Table a) => Eval (_Columns a) context -> a)
63+ -> GColumns _Columns rep context
64+ -> rep x
65+
66+ gtoColumns :: ()
67+ => (forall a. Eval (_Table a) => a -> Eval (_Columns a) context)
68+ -> rep x
69+ -> GColumns _Columns rep context
70+
71+ gtable :: ()
72+ => (forall a proxy. Eval (_Table a) => proxy a -> Eval (_Columns a) context)
73+ -> GColumns _Columns rep context
74+
75+
76+type GSerialize
77+ :: (Type -> Type -> Exp Constraint)
78+ -> (Type -> Exp K.HTable)
79+ -> (Type -> Type) -> (Type -> Type) -> Constraint
80+class GSerialize _Serialize _Columns exprs rep
81+ where
82+ gfromResult :: ()
83+ => (forall expr a proxy. Eval (_Serialize expr a)
84+ => proxy expr -> Eval (_Columns expr) context -> a)
85+ -> GColumns _Columns exprs context
86+ -> rep x
87+
88+ gtoResult :: ()
89+ => (forall expr a proxy. Eval (_Serialize expr a)
90+ => proxy expr -> a -> Eval (_Columns expr) context)
91+ -> rep x
92+ -> GColumns _Columns exprs context
93+
94+
95+instance GTable _Table _Columns rep => GTable _Table _Columns (M1 D c rep)
96+ where
97+ gfromColumns fromColumns =
98+ M1 . gfromColumns @_Table @_Columns @rep fromColumns
99+ gtoColumns toColumns (M1 a) =
100+ gtoColumns @_Table @_Columns @rep toColumns a
101+ gtable = gtable @_Table @_Columns @rep
102+
103+
104+instance GSerialize _Serialize _Columns exprs rep =>
105+ GSerialize _Serialize _Columns (M1 D c exprs) (M1 D c rep)
106+ where
107+ gfromResult fromResult =
108+ M1 . gfromResult @_Serialize @_Columns @exprs @rep fromResult
109+ gtoResult toResult (M1 a) =
110+ gtoResult @_Serialize @_Columns @exprs @rep toResult a
111+
112+
113+instance GTable _Table _Columns rep => GTable _Table _Columns (M1 C c rep)
114+ where
115+ gfromColumns fromColumns =
116+ M1 . gfromColumns @_Table @_Columns @rep fromColumns
117+ gtoColumns toColumns (M1 a) =
118+ gtoColumns @_Table @_Columns @rep toColumns a
119+ gtable = gtable @_Table @_Columns @rep
120+
121+
122+instance GSerialize _Serialize _Columns exprs rep =>
123+ GSerialize _Serialize _Columns (M1 C c exprs) (M1 C c rep)
124+ where
125+ gfromResult fromResult =
126+ M1 . gfromResult @_Serialize @_Columns @exprs @rep fromResult
127+ gtoResult toResult (M1 a) =
128+ gtoResult @_Serialize @_Columns @exprs @rep toResult a
129+
130+
131+instance (GTable _Table _Columns rep1, GTable _Table _Columns rep2) =>
132+ GTable _Table _Columns (rep1 :*: rep2)
133+ where
134+ gfromColumns fromColumns (HProduct a b) =
135+ gfromColumns @_Table @_Columns @rep1 fromColumns a :*:
136+ gfromColumns @_Table @_Columns @rep2 fromColumns b
137+ gtoColumns toColumns (a :*: b) = HProduct
138+ (gtoColumns @_Table @_Columns @rep1 toColumns a)
139+ (gtoColumns @_Table @_Columns @rep2 toColumns b)
140+ gtable table = HProduct
141+ (gtable @_Table @_Columns @rep1 table)
142+ (gtable @_Table @_Columns @rep2 table)
143+
144+
145+instance
146+ ( GSerialize _Serialize _Columns expr1 rep1
147+ , GSerialize _Serialize _Columns expr2 rep2
148+ )
149+ => GSerialize _Serialize _Columns (expr1 :*: expr2) (rep1 :*: rep2)
150+ where
151+ gfromResult fromResult (HProduct a b) =
152+ gfromResult @_Serialize @_Columns @expr1 @rep1 fromResult a :*:
153+ gfromResult @_Serialize @_Columns @expr2 @rep2 fromResult b
154+ gtoResult toResult (a :*: b) =
155+ HProduct
156+ (gtoResult @_Serialize @_Columns @expr1 @rep1 toResult a)
157+ (gtoResult @_Serialize @_Columns @expr2 @rep2 toResult b)
158+
159+
160+instance
161+ ( Eval (_Table a)
162+ , meta ~ 'MetaSel ('Just label) _su _ss _ds
163+ , k1 ~ K1 i a
164+ )
165+ => GTable _Table _Columns (M1 S meta k1)
166+ where
167+ gfromColumns fromColumns = M1 . K1 . fromColumns . hunlabel
168+ gtoColumns toColumns (M1 (K1 a)) = hlabel (toColumns a)
169+ gtable table = hlabel (table (Proxy @a))
170+
171+
172+instance
173+ ( Eval (_Serialize expr a)
174+ , meta ~ 'MetaSel ('Just label) _su _ss _ds
175+ , k1 ~ K1 i expr
176+ , k1' ~ K1 i a
177+ )
178+ => GSerialize _Serialize _Columns (M1 S meta k1) (M1 S meta k1')
179+ where
180+ gfromResult fromResult = M1 . K1 . fromResult (Proxy @expr) . hunlabel
181+ gtoResult toResult (M1 (K1 a)) = hlabel (toResult (Proxy @expr) a)
src/Rel8/Kind/Algebra.hsnew file+38
@@ -0,0 +1,38 @@
1+{-# language DataKinds #-}
2+{-# language FlexibleContexts #-}
3+{-# language GADTs #-}
4+{-# language StandaloneKindSignatures #-}
5+
6+module Rel8.Kind.Algebra
7+ ( Algebra( Product, Sum )
8+ , SAlgebra( SProduct, SSum )
9+ , KnownAlgebra( algebraSing )
10+ )
11+where
12+
13+-- base
14+import Data.Kind ( Constraint, Type )
15+import Prelude ()
16+
17+
18+type Algebra :: Type
19+data Algebra = Product | Sum
20+
21+
22+type SAlgebra :: Algebra -> Type
23+data SAlgebra algebra where
24+ SProduct :: SAlgebra 'Product
25+ SSum :: SAlgebra 'Sum
26+
27+
28+type KnownAlgebra :: Algebra -> Constraint
29+class KnownAlgebra algebra where
30+ algebraSing :: SAlgebra algebra
31+
32+
33+instance KnownAlgebra 'Product where
34+ algebraSing = SProduct
35+
36+
37+instance KnownAlgebra 'Sum where
38+ algebraSing = SSum
src/Rel8/Kind/Context.hsnew file+56
@@ -0,0 +1,56 @@
1+{-# language DataKinds #-}
2+{-# language GADTs #-}
3+{-# language StandaloneKindSignatures #-}
4+{-# language TypeSynonymInstances #-}
5+
6+module Rel8.Kind.Context
7+ ( Reifiable( contextSing )
8+ , SContext(..)
9+ )
10+where
11+
12+-- base
13+import Data.Kind ( Constraint, Type )
14+import Prelude ()
15+
16+-- rel8
17+import Rel8.Aggregate ( Aggregate )
18+import Rel8.Expr ( Expr )
19+import Rel8.Schema.Field ( Field )
20+import Rel8.Schema.Kind ( Context )
21+import Rel8.Schema.Name ( Name )
22+import Rel8.Schema.Result ( Result )
23+
24+
25+type SContext :: Context -> Type
26+data SContext context where
27+ SAggregate :: SContext Aggregate
28+ SExpr :: SContext Expr
29+ SField :: SContext (Field table)
30+ SName :: SContext Name
31+ SResult :: SContext Result
32+
33+
34+type Reifiable :: Context -> Constraint
35+class Reifiable context where
36+ contextSing :: SContext context
37+
38+
39+instance Reifiable Aggregate where
40+ contextSing = SAggregate
41+
42+
43+instance Reifiable Expr where
44+ contextSing = SExpr
45+
46+
47+instance Reifiable (Field table) where
48+ contextSing = SField
49+
50+
51+instance Reifiable Result where
52+ contextSing = SResult
53+
54+
55+instance Reifiable Name where
56+ contextSing = SName
src/Rel8/Kind/Labels.hsdeleted−61
@@ -1,61 +0,0 @@
1−{-# language DataKinds #-}
2−{-# language FlexibleContexts #-}
3−{-# language FlexibleInstances #-}
4−{-# language GADTs #-}
5−{-# language LambdaCase #-}
6−{-# language StandaloneKindSignatures #-}
7−{-# language TypeOperators #-}
8−
9−module Rel8.Kind.Labels
10− ( Labels
11− , SLabels( SLabel, SLabels )
12− , KnownLabels( labelsSing )
13− , renderLabels
14− )
15−where
16−
17−-- base
18−import Data.Kind ( Constraint, Type )
19−import Data.List.NonEmpty ( NonEmpty( (:|) ), (<|) )
20−import Data.Proxy ( Proxy( Proxy ) )
21−import GHC.TypeLits ( KnownSymbol, Symbol, symbolVal )
22−import Prelude
23−
24−
25−type Labels :: Type
26−type Labels = [Symbol]
27−
28−
29−type SLabels :: Labels -> Type
30−data SLabels labels where
31− SLabel :: KnownSymbol label => Proxy label -> SLabels '[label]
32− SLabels :: KnownSymbol label => Proxy label -> SLabels labels -> SLabels (label ': labels)
33−
34−
35−type KnownLabels :: Labels -> Constraint
36−class KnownLabels labels where
37− labelsSing :: SLabels labels
38−
39−
40−instance KnownSymbol label => KnownLabels (label ': '[]) where
41− labelsSing = SLabel Proxy
42−
43−
44−instance (KnownSymbol label, KnownLabels (label_ ': labels)) =>
45− KnownLabels (label ': (label_ ': labels))
46− where
47− labelsSing = SLabels Proxy labelsSing
48−
49−
50−renderLabels :: SLabels labels -> NonEmpty String
51−renderLabels = cleanup . go
52− where
53− go :: SLabels labels -> NonEmpty String
54− go = \case
55− SLabel label -> pure (symbolVal label)
56− SLabels label labels -> symbolVal label <| go labels
57−
58− cleanup ("" :| []) = "anon" :| []
59− cleanup (a :| []) = a :| []
60− cleanup (a :| [""]) = a :| []
61− cleanup (a :| (b : c)) = a <| cleanup (b :| c)
src/Rel8/Kind/Necessity.hsdeleted−38
@@ -1,38 +0,0 @@
1−{-# language DataKinds #-}
2−{-# language FlexibleContexts #-}
3−{-# language GADTs #-}
4−{-# language StandaloneKindSignatures #-}
5−
6−module Rel8.Kind.Necessity
7− ( Necessity( Optional, Required )
8− , SNecessity( SOptional, SRequired )
9− , KnownNecessity( necessitySing )
10− )
11−where
12−
13−-- base
14−import Data.Kind ( Constraint, Type )
15−import Prelude ()
16−
17−
18−type Necessity :: Type
19−data Necessity = Optional | Required
20−
21−
22−type SNecessity :: Necessity -> Type
23−data SNecessity necessity where
24− SOptional :: SNecessity 'Optional
25− SRequired :: SNecessity 'Required
26−
27−
28−type KnownNecessity :: Necessity -> Constraint
29−class KnownNecessity necessity where
30− necessitySing :: SNecessity necessity
31−
32−
33−instance KnownNecessity 'Optional where
34− necessitySing = SOptional
35−
36−
37−instance KnownNecessity 'Required where
38− necessitySing = SRequired
src/Rel8/Opaque.hsdeleted−20
@@ -1,20 +0,0 @@
1−{-# language PolyKinds #-}
2−{-# language StandaloneKindSignatures #-}
3−
4−module Rel8.Opaque
5− ( Opaque
6− , Opaque1
7− )
8−where
9−
10−-- base
11−import Data.Kind ( Type )
12−import Prelude ()
13−
14−
15−type Opaque :: Type
16−data Opaque
17−
18−
19−type Opaque1 :: k -> Type -> Type
20−data Opaque1 a x
src/Rel8/Order.hs+5−14
@@ -16,24 +16,15 @@ import Prelude
16import Data.Functor.Contravariant.Divisible ( Decidable, Divisible )
16import Data.Functor.Contravariant.Divisible ( Decidable, Divisible )
17
17
18-- opaleye
18-- opaleye
19−import qualified Opaleye.Internal.Order as Opaleye
19+import qualified Opaleye.Order as Opaleye
20
20
21
21
22−-- | An ordering expression for @a@. Primitive orderings are defined with 'asc'
22+-- | An ordering expression for @a@. Primitive orderings are defined with
23−-- and 'desc', and you can combine @Order@ via its various instances.
23+-- 'Rel8.asc' and 'Rel8.desc', and you can combine @Order@ via its various
24+-- instances.
24--
25--
25-- A common pattern is to use '<>' to combine multiple orderings in sequence,
26-- A common pattern is to use '<>' to combine multiple orderings in sequence,
26−-- and '>$<' (from 'Contravariant') to select individual columns. For example,
27−-- to sort a @Query@ on two columns, we could do:
28−--
29−-- >>> import Data.Functor.Contravariant ((>$<))
27+-- and 'Data.Functor.Contravariant.>$<' to select individual columns.
30−-- >>> :{
31−-- select c $ orderBy (mconcat [fst >$< asc, snd >$< desc]) $ do
32−-- x <- values [ lit x | x <- [1..3 :: Int32 ] ]
33−-- y <- values [ lit x | x <- [1..3 :: Int32 ] ]
34−-- return (x, y)
35−-- :}
36−-- [(1,3),(1,2),(1,1),(2,3),(2,2),(2,1),(3,3),(3,2),(3,1)]
37type Order :: Type -> Type
28type Order :: Type -> Type
38newtype Order a = Order (Opaleye.Order a)
29newtype Order a = Order (Opaleye.Order a)
39 deriving newtype (Contravariant, Divisible, Decidable, Semigroup, Monoid)
30 deriving newtype (Contravariant, Divisible, Decidable, Semigroup, Monoid)
src/Rel8/Query.hs+192−5
@@ -1,6 +1,6 @@
1−{-# language DerivingStrategies #-}
1+{-# language FlexibleContexts #-}
2−{-# language GeneralizedNewtypeDeriving #-}
3{-# language StandaloneKindSignatures #-}
2{-# language StandaloneKindSignatures #-}
3+{-# language UndecidableInstances #-}
4
4
5module Rel8.Query
5module Rel8.Query
6 ( Query( Query )
6 ( Query( Query )
@@ -8,29 +8,216 @@ module Rel8.Query
8where
8where
9
9
10-- base
10-- base
11+import Control.Applicative ( liftA2 )
12+import Control.Monad ( liftM2 )
11import Data.Kind ( Type )
13import Data.Kind ( Type )
14+import Data.Monoid ( Any( Any ) )
12import Prelude
15import Prelude
13
16
14-- opaleye
17-- opaleye
15−import qualified Opaleye.Select as Opaleye
18+import qualified Opaleye.Internal.HaskellDB.PrimQuery as Opaleye
19+import qualified Opaleye.Internal.PackMap as Opaleye
20+import qualified Opaleye.Internal.PrimQuery as Opaleye hiding (lateral)
21+import qualified Opaleye.Internal.QueryArr as Opaleye
22+import qualified Opaleye.Internal.Tag as Opaleye
16
23
17-- rel8
24-- rel8
25+import Rel8.Expr ( Expr )
18import Rel8.Query.Set ( unionAll )
26import Rel8.Query.Set ( unionAll )
27+import Rel8.Query.Opaleye ( fromOpaleye )
19import Rel8.Query.Values ( values )
28import Rel8.Query.Values ( values )
29+import Rel8.Table ( Table, fromColumns, toColumns )
20import Rel8.Table.Alternative
30import Rel8.Table.Alternative
21 ( AltTable, (<|>:)
31 ( AltTable, (<|>:)
22 , AlternativeTable, emptyTable
32 , AlternativeTable, emptyTable
23 )
33 )
34+import Rel8.Table.Projection ( Projectable, apply, project )
24
35
36+-- semigroupoids
37+import Data.Functor.Apply ( Apply, (<.>) )
38+import Data.Functor.Bind ( Bind, (>>-) )
25
39
40+
41+-- | The @Query@ monad allows you to compose a @SELECT@ query. This monad has
42+-- semantics similar to the list (@[]@) monad.
26type Query :: Type -> Type
43type Query :: Type -> Type
27−newtype Query a = Query (Opaleye.Select a)
44+newtype Query a =
28− deriving newtype (Functor, Applicative, Monad)
45+ Query (
46+ -- This is based on Opaleye's Select monad, but with two addtions. We
47+ -- maintain a stack of PrimExprs from parent previous subselects. In
48+ -- practice, these are always the results of dummy calls to random().
49+ --
50+ -- We also return a Bool that indicates to the parent subselect whether
51+ -- or not that stack of PrimExprs were used at any point. If they weren't,
52+ -- then the call to random() is never added to the query.
53+ --
54+ -- This is all needed to implement evaluate. Consider the following code:
55+ --
56+ -- do
57+ -- x <- values [lit 'a', lit 'b', lit 'c']
58+ -- y <- evaluate $ nextval "user_id_seq"
59+ -- pure (x, y)
60+ --
61+ -- If we just used Opaleye's Select monad directly, the SQL would come out
62+ -- like this:
63+ --
64+ -- SELECT
65+ -- a, b
66+ -- FROM
67+ -- (VALUES ('a'), ('b'), ('c')) Q1(a),
68+ -- LATERAL (SELECT nextval('user_id_seq')) Q2(b);
69+ --
70+ -- From the Haskell code, you would intuitively expect to get back the
71+ -- results of three different calls to nextval(), but from Postgres' point
72+ -- of view, because the Q2 subquery doesn't reference anything from the Q1
73+ -- query, it thinks it only needs to call nextval() once. This is actually
74+ -- exactly the same problem you get with the deprecated ListT IO monad from
75+ -- the transformers package — *> behaves differently to >>=, so
76+ -- using ApplicativeDo can change the results of a program. ApplicativeDo
77+ -- is exactly the optimisation Postgres does on a "LATERAL" query that
78+ -- doesn't make any references to previous subselects.
79+ --
80+ -- Rel8's solution is generate the following SQL instead:
81+ --
82+ -- SELECT
83+ -- a, b
84+ -- FROM
85+ -- (SELECT
86+ -- random() AS dummy,
87+ -- *
88+ -- FROM
89+ -- (VALUES ('a'), ('b'), ('c')) Q1(a)) Q1,
90+ -- LATERAL (SELECT
91+ -- CASE
92+ -- WHEN dummy IS NOT NULL
93+ -- THEN nextval('user_id_seq')
94+ -- END) Q2(b);
95+ --
96+ -- We use random() here as the dummy value (and not some constant) because
97+ -- Postgres will again optimize if it sees that a value is constant
98+ -- (and thus only call nextval() once), but because random() is marked as
99+ -- VOLATILE, this inhibits Postgres from doing that optimisation.
100+ --
101+ -- Why not just reference the a column from the previous query directly
102+ -- instead of adding a dummy value? Basically, even if we extract out all
103+ -- the bindings introduced in a PrimQuery, we can't always be sure which
104+ -- ones refer to constant values, so if we end up laterally referencing a
105+ -- constant value, then all of this would be for nothing.
106+ --
107+ -- Why not just add the call to the previous subselect directly, like so:
108+ --
109+ -- SELECT
110+ -- a, b
111+ -- FROM
112+ -- (SELECT
113+ -- nextval('user_id_seq') AS eval,
114+ -- *
115+ -- FROM
116+ -- (VALUES ('a'), ('b'), ('c')) Q1(a)) Q1,
117+ -- LATERAL (SELECT eval) Q2(b);
118+ --
119+ -- That would work in this case. But consider the following Rel8 code:
120+ --
121+ -- do
122+ -- x <- values [lit 'a', lit 'b', lit 'c']
123+ -- y <- values [lit 'd', lit 'e', lit 'f']
124+ -- z <- evaluate $ nextval "user_id_seq"
125+ -- pure (x, y, z)
126+ --
127+ -- How many calls to nextval should there be? Our Haskell intuition says
128+ -- nine. But that's not what you would get if you used the above
129+ -- technique. The problem is, which VALUES query should the nextval be
130+ -- added to? You can choose one or the other to get three calls to
131+ -- nextval, but you still need to make a superfluous LATERAL references to
132+ -- the other if you want nine calls. So for the above Rel8 code we generate
133+ -- the following SQL:
134+ --
135+ -- SELECT
136+ -- a, b, c
137+ -- FROM
138+ -- (SELECT
139+ -- random() AS dummy,
140+ -- *
141+ -- FROM
142+ -- (VALUES ('a'), ('b'), ('c')) Q1(a)) Q1,
143+ -- (SELECT
144+ -- random() AS dummy,
145+ -- *
146+ -- FROM
147+ -- (VALUES ('d'), ('e'), ('f')) Q2(b)) Q2,
148+ -- LATERAL (SELECT
149+ -- CASE
150+ -- WHEN Q1.dummy IS NOT NULL AND Q2.dummy IS NOT NULL
151+ -- THEN nextval('user_id_seq')
152+ -- END) Q3(c);
153+ --
154+ -- This gives nine calls to nextval() as we would expect.
155+ [Opaleye.PrimExpr] -> Opaleye.Select (Any, a)
156+ )
157+
158+
159+instance Projectable Query where
160+ project f = fmap (fromColumns . apply f . toColumns)
161+
162+
163+instance Functor Query where
164+ fmap f (Query a) = Query (fmap (fmap (fmap f)) a)
165+
166+
167+instance Apply Query where
168+ (<.>) = (<*>)
169+
29
170
171+instance Applicative Query where
172+ pure = fromOpaleye . pure
173+ liftA2 = liftM2
30
174
175+
176+instance Bind Query where
177+ (>>-) = (>>=)
178+
179+
180+instance Monad Query where
181+ Query q >>= f = Query $ \dummies -> Opaleye.stateQueryArr $ \_ tag ->
182+ let
183+ qa = q dummies
184+ ((m, a), query, tag') = Opaleye.runStateQueryArr qa () tag
185+ Query q' = f a
186+ (dummies', query', tag'') =
187+ ( dummy : dummies
188+ , query <> Opaleye.aRebind bindings
189+ , Opaleye.next tag'
190+ )
191+ where
192+ (dummy, bindings) = Opaleye.run $ name random
193+ where
194+ random = Opaleye.FunExpr "random" []
195+ name = Opaleye.extractAttr "dummy" tag'
196+ qa' = Opaleye.lateral $ \_ -> q' dummies'
197+ ((m'@(Any needsDummies), b), query'', tag''') = Opaleye.runStateQueryArr qa' () tag''
198+ query'''
199+ | needsDummies = query' <> query''
200+ | otherwise = query <> query''
201+ m'' = m <> m'
202+ in
203+ ((m'', b), query''', tag''')
204+
205+
206+-- | '<|>:' = 'unionAll'.
31instance AltTable Query where
207instance AltTable Query where
32 (<|>:) = unionAll
208 (<|>:) = unionAll
33
209
34
210
211+-- | 'emptyTable' = 'values' @[]@.
35instance AlternativeTable Query where
212instance AlternativeTable Query where
36 emptyTable = values []
213 emptyTable = values []
214+
215+
216+-- | '<>' = 'unionAll'.
217+instance Table Expr a => Semigroup (Query a) where
218+ (<>) = (<|>:)
219+
220+
221+-- | 'mempty' = @'values' []@.
222+instance Table Expr a => Monoid (Query a) where
223+ mempty = emptyTable
src/Rel8/Query.hs-boot+3−1
@@ -7,11 +7,13 @@ where
7
7
8-- base
8-- base
9import Data.Kind ( Type )
9import Data.Kind ( Type )
10+import Data.Monoid ( Any )
10import Prelude ()
11import Prelude ()
11
12
12-- opaleye
13-- opaleye
14+import qualified Opaleye.Internal.HaskellDB.PrimQuery as Opaleye
13import qualified Opaleye.Select as Opaleye
15import qualified Opaleye.Select as Opaleye
14
16
15
17
16type Query :: Type -> Type
18type Query :: Type -> Type
17−newtype Query a = Query (Opaleye.Select a)
19+newtype Query a = Query ([Opaleye.PrimExpr] -> Opaleye.Select (Any, a))
src/Rel8/Query/Aggregate.hs+36−3
@@ -1,23 +1,56 @@
1{-# language FlexibleContexts #-}
1{-# language FlexibleContexts #-}
2+{-# language MonoLocalBinds #-}
3+{-# language ScopedTypeVariables #-}
4+{-# language TypeApplications #-}
2
5
3module Rel8.Query.Aggregate
6module Rel8.Query.Aggregate
4 ( aggregate
7 ( aggregate
8+ , countRows
9+ , mode
5 )
10 )
6where
11where
7
12
8-- base
13-- base
14+import Data.Functor.Contravariant ( (>$<) )
15+import Data.Int ( Int64 )
9−import Prelude ()
16+import Prelude
10
17
11-- opaleye
18-- opaleye
12import qualified Opaleye.Aggregate as Opaleye
19import qualified Opaleye.Aggregate as Opaleye
13
20
14-- rel8
21-- rel8
15−import Rel8.Aggregate ( Aggregate )
22+import Rel8.Aggregate ( Aggregates )
23+import Rel8.Expr ( Expr )
24+import Rel8.Expr.Aggregate ( countStar )
25+import Rel8.Expr.Order ( desc )
16import Rel8.Query ( Query )
26import Rel8.Query ( Query )
27+import Rel8.Query.Limit ( limit )
28+import Rel8.Query.Maybe ( optional )
17import Rel8.Query.Opaleye ( mapOpaleye )
29import Rel8.Query.Opaleye ( mapOpaleye )
30+import Rel8.Query.Order ( orderBy )
31+import Rel8.Table ( toColumns )
32+import Rel8.Table.Aggregate ( hgroupBy )
33+import Rel8.Table.Cols ( Cols( Cols ), fromCols )
34+import Rel8.Table.Eq ( EqTable, eqTable )
18import Rel8.Table.Opaleye ( aggregator )
35import Rel8.Table.Opaleye ( aggregator )
36+import Rel8.Table.Maybe ( maybeTable )
19
37
20
38
21-- | Apply an aggregation to all rows returned by a 'Query'.
39-- | Apply an aggregation to all rows returned by a 'Query'.
22−aggregate :: Query (Aggregate exprs) -> Query exprs
40+aggregate :: Aggregates aggregates exprs => Query aggregates -> Query exprs
23aggregate = mapOpaleye (Opaleye.aggregate aggregator)
41aggregate = mapOpaleye (Opaleye.aggregate aggregator)
42+
43+
44+-- | Count the number of rows returned by a query. Note that this is different
45+-- from @countStar@, as even if the given query yields no rows, @countRows@
46+-- will return @0@.
47+countRows :: Query a -> Query (Expr Int64)
48+countRows = fmap (maybeTable 0 id) . optional . aggregate . fmap (const countStar)
49+
50+
51+-- | Return the most common row in a query.
52+mode :: forall a. EqTable a => Query a -> Query a
53+mode rows = limit 1 $ fmap (fromCols . snd) $ orderBy (fst >$< desc) $ do
54+ aggregate $ do
55+ row <- toColumns <$> rows
56+ pure (countStar, Cols $ hgroupBy (eqTable @a) row)
src/Rel8/Query/Distinct.hs+4−12
@@ -1,5 +1,3 @@
1−{-# options_ghc -fno-warn-redundant-constraints #-}
2−
3module Rel8.Query.Distinct
1module Rel8.Query.Distinct
4 ( distinct
2 ( distinct
5 , distinctOn
3 , distinctOn
@@ -8,12 +6,11 @@ module Rel8.Query.Distinct
8where
6where
9
7
10-- base
8-- base
11−import Prelude
9+import Prelude ()
12
10
13-- opaleye
11-- opaleye
14import qualified Opaleye.Distinct as Opaleye
12import qualified Opaleye.Distinct as Opaleye
15−import qualified Opaleye.Internal.Order as Opaleye
13+import qualified Opaleye.Order as Opaleye
16−import qualified Opaleye.Internal.QueryArr as Opaleye
17
14
18-- rel8
15-- rel8
19import Rel8.Order ( Order( Order ) )
16import Rel8.Order ( Order( Order ) )
@@ -25,9 +22,6 @@ import Rel8.Table.Opaleye ( distinctspec, unpackspec )
25
22
26-- | Select all distinct rows from a query, removing duplicates. @distinct q@
23-- | Select all distinct rows from a query, removing duplicates. @distinct q@
27-- is equivalent to the SQL statement @SELECT DISTINCT q@.
24-- is equivalent to the SQL statement @SELECT DISTINCT q@.
28−--
29−-- >>> select c $ distinct $ values [ lit True, lit True, lit False ]
30−-- [False,True]
31distinct :: EqTable a => Query a -> Query a
25distinct :: EqTable a => Query a -> Query a
32distinct = mapOpaleye (Opaleye.distinctExplicit distinctspec)
26distinct = mapOpaleye (Opaleye.distinctExplicit distinctspec)
33
27
@@ -36,13 +30,11 @@ distinct = mapOpaleye (Opaleye.distinctExplicit distinctspec)
36-- to a projection. If multiple rows have the same projection, it is
30-- to a projection. If multiple rows have the same projection, it is
37-- unspecified which row will be returned. If this matters, use 'distinctOnBy'.
31-- unspecified which row will be returned. If this matters, use 'distinctOnBy'.
38distinctOn :: EqTable b => (a -> b) -> Query a -> Query a
32distinctOn :: EqTable b => (a -> b) -> Query a -> Query a
39−distinctOn proj =
40− mapOpaleye (\q -> Opaleye.productQueryArr (Opaleye.distinctOn unpackspec proj . Opaleye.runSimpleQueryArr q))
33+distinctOn proj = mapOpaleye (Opaleye.distinctOnExplicit unpackspec proj)
41
34
42
35
43-- | Select all distinct rows from a query, where rows are equivalent according
36-- | Select all distinct rows from a query, where rows are equivalent according
44-- to a projection. If there are multiple rows with the same projection, the
37-- to a projection. If there are multiple rows with the same projection, the
45-- first row according to the specified 'Order' will be returned.
38-- first row according to the specified 'Order' will be returned.
46distinctOnBy :: EqTable b => (a -> b) -> Order a -> Query a -> Query a
39distinctOnBy :: EqTable b => (a -> b) -> Order a -> Query a -> Query a
47−distinctOnBy proj (Order order) =
40+distinctOnBy proj (Order order) = mapOpaleye (Opaleye.distinctOnByExplicit unpackspec proj order)
48− mapOpaleye (\q -> Opaleye.productQueryArr (Opaleye.distinctOnBy unpackspec proj order . Opaleye.runSimpleQueryArr q))
src/Rel8/Query/Each.hs+5−9
@@ -1,4 +1,5 @@
1{-# language FlexibleContexts #-}
1{-# language FlexibleContexts #-}
2+{-# language MonoLocalBinds #-}
2
3
3module Rel8.Query.Each
4module Rel8.Query.Each
4 ( each
5 ( each
@@ -14,23 +15,18 @@ import qualified Opaleye.Table as Opaleye
14-- rel8
15-- rel8
15import Rel8.Query ( Query )
16import Rel8.Query ( Query )
16import Rel8.Query.Opaleye ( fromOpaleye )
17import Rel8.Query.Opaleye ( fromOpaleye )
18+import Rel8.Schema.Name ( Selects )
17import Rel8.Schema.Table ( TableSchema )
19import Rel8.Schema.Table ( TableSchema )
18−import Rel8.Table ( fromColumns, toColumns )
20+import Rel8.Table.Cols ( fromCols, toCols )
19import Rel8.Table.Opaleye ( table, unpackspec )
21import Rel8.Table.Opaleye ( table, unpackspec )
20−import Rel8.Table.Recontextualize ( Selects )
21
22
22
23
23-- | Select each row from a table definition. This is equivalent to @FROM
24-- | Select each row from a table definition. This is equivalent to @FROM
24-- table@.
25-- table@.
25−--
26−-- >>> mapM_ print =<< select c (each projectSchema)
27−-- Project {projectAuthorId = 1, projectName = "rel8"}
28−-- Project {projectAuthorId = 2, projectName = "aeson"}
29−-- Project {projectAuthorId = 2, projectName = "text"}
30each :: Selects names exprs => TableSchema names -> Query exprs
26each :: Selects names exprs => TableSchema names -> Query exprs
31each =
27each =
32− fmap fromColumns .
28+ fmap fromCols .
33 fromOpaleye .
29 fromOpaleye .
34 Opaleye.selectTableExplicit unpackspec .
30 Opaleye.selectTableExplicit unpackspec .
35 table .
31 table .
36− fmap toColumns
32+ fmap toCols
src/Rel8/Query/Either.hs+34−30
@@ -3,63 +3,67 @@
3module Rel8.Query.Either
3module Rel8.Query.Either
4 ( keepLeftTable
4 ( keepLeftTable
5 , keepRightTable
5 , keepRightTable
6− , bindEitherTable
7 , bitraverseEitherTable
6 , bitraverseEitherTable
8 )
7 )
9where
8where
10
9
11-- base
10-- base
12−import Data.Functor ( (<&>) )
13import Prelude
11import Prelude
14
12
13+-- comonad
14+import Control.Comonad ( extract )
15+
15-- rel8
16-- rel8
16import Rel8.Expr ( Expr )
17import Rel8.Expr ( Expr )
17import Rel8.Expr.Eq ( (==.) )
18import Rel8.Expr.Eq ( (==.) )
18import Rel8.Query ( Query )
19import Rel8.Query ( Query )
19import Rel8.Query.Filter ( where_ )
20import Rel8.Query.Filter ( where_ )
20import Rel8.Query.Maybe ( optional )
21import Rel8.Query.Maybe ( optional )
21−import Rel8.Query.Set ( unionAll )
22−import Rel8.Table ( Table )
23−import Rel8.Table.Bool ( bool )
24import Rel8.Table.Either
22import Rel8.Table.Either
25 ( EitherTable( EitherTable )
23 ( EitherTable( EitherTable )
26− , leftTable, rightTable
27 , isLeftTable, isRightTable
24 , isLeftTable, isRightTable
28 )
25 )
29import Rel8.Table.Maybe ( MaybeTable( MaybeTable ), isJustTable )
26import Rel8.Table.Maybe ( MaybeTable( MaybeTable ), isJustTable )
30
27
31
28
29+-- | Filter 'EitherTable's, keeping only 'leftTable's.
32−keepLeftTable :: EitherTable a b -> Query a
30+keepLeftTable :: EitherTable Expr a b -> Query a
33keepLeftTable e@(EitherTable _ a _) = do
31keepLeftTable e@(EitherTable _ a _) = do
34 where_ $ isLeftTable e
32 where_ $ isLeftTable e
35− pure a
33+ pure (extract a)
36
34
37
35
36+-- | Filter 'EitherTable's, keeping only 'rightTable's.
38−keepRightTable :: EitherTable a b -> Query b
37+keepRightTable :: EitherTable Expr a b -> Query b
39keepRightTable e@(EitherTable _ _ b) = do
38keepRightTable e@(EitherTable _ _ b) = do
40 where_ $ isRightTable e
39 where_ $ isRightTable e
41− pure b
40+ pure (extract b)
42−
43−
44−bindEitherTable :: (Table Expr a, Functor m)
45− => (i -> m (EitherTable a b)) -> EitherTable a i -> m (EitherTable a b)
46−bindEitherTable query e@(EitherTable input a i) = do
47− query i <&> \(EitherTable output a' b) ->
48− EitherTable (input <> output) (bool a a' (isRightTable e)) b
49
41
50
42
51−bitraverseEitherTable :: (Table Expr c, Table Expr d)
43+-- | @bitraverseEitherTable f g x@ will pass all @leftTable@s through @f@ and
44+-- all @rightTable@s through @g@. The results are then lifted back into
45+-- @leftTable@ and @rightTable@, respectively. This is similar to 'bitraverse'
46+-- for 'Either'.
47+--
48+-- For example,
49+--
50+-- >>> :{
51+-- select do
52+-- x <- values (map lit [ Left True, Right (42 :: Int32) ])
53+-- bitraverseEitherTable (\y -> values [y, not_ y]) (\y -> pure (y * 100)) x
54+-- :}
55+-- [ Left True
56+-- , Left False
57+-- , Right 4200
58+-- ]
59+bitraverseEitherTable :: ()
52 => (a -> Query c)
60 => (a -> Query c)
53 -> (b -> Query d)
61 -> (b -> Query d)
54− -> EitherTable a b
62+ -> EitherTable Expr a b
55− -> Query (EitherTable c d)
63+ -> Query (EitherTable Expr c d)
56−bitraverseEitherTable f g e = traverseLeftTable `unionAll` traverseRightTable
64+bitraverseEitherTable f g e@(EitherTable tag _ _) = do
57− where
58− traverseLeftTable = do
59− mc@(MaybeTable _ c) <- optional (f =<< keepLeftTable e)
65+ mc@(MaybeTable _ c) <- optional (f =<< keepLeftTable e)
60− where_ $ isJustTable mc ==. isLeftTable e
61− pure $ leftTable c
62− traverseRightTable = do
63− md@(MaybeTable _ d) <- optional (g =<< keepRightTable e)
66+ md@(MaybeTable _ d) <- optional (g =<< keepRightTable e)
67+ where_ $ isJustTable mc ==. isLeftTable e
64− where_ $ isJustTable md ==. isRightTable e
68+ where_ $ isJustTable md ==. isRightTable e
65− pure $ rightTable d
69+ pure $ EitherTable tag c d
src/Rel8/Query/Evaluate.hsnew file+49
@@ -0,0 +1,49 @@
1+{-# language FlexibleContexts #-}
2+{-# language TupleSections #-}
3+
4+module Rel8.Query.Evaluate
5+ ( evaluate
6+ )
7+where
8+
9+-- base
10+import Control.Monad ( (>=>) )
11+import Data.Foldable ( foldl' )
12+import Data.List.NonEmpty ( NonEmpty( (:|) ), nonEmpty )
13+import Data.Monoid ( Any( Any ) )
14+import Prelude hiding ( undefined )
15+
16+-- opaleye
17+import qualified Opaleye.Internal.HaskellDB.PrimQuery as Opaleye
18+
19+-- rel8
20+import Rel8.Expr ( Expr )
21+import Rel8.Expr.Bool ( (&&.) )
22+import Rel8.Expr.Opaleye ( fromPrimExpr )
23+import Rel8.Query ( Query( Query ) )
24+import Rel8.Query.Rebind ( rebind )
25+import Rel8.Table ( Table )
26+import Rel8.Table.Bool ( case_ )
27+import Rel8.Table.Undefined ( undefined )
28+
29+
30+-- | 'evaluate' takes expressions that could potentially have side effects and
31+-- \"runs\" them in the 'Query' monad. The returned expressions have no side
32+-- effects and can safely be reused.
33+evaluate :: Table Expr a => a -> Query a
34+evaluate = laterally >=> rebind "eval"
35+
36+
37+laterally :: Table Expr a => a -> Query a
38+laterally a = Query $ \bindings -> pure $ (Any True,) $
39+ case nonEmpty bindings of
40+ Nothing -> a
41+ Just bindings' -> case_ [(condition, a)] undefined
42+ where
43+ condition = foldl1' (&&.) (fmap go bindings')
44+ where
45+ go = fromPrimExpr . Opaleye.UnExpr Opaleye.OpIsNotNull
46+
47+
48+foldl1' :: (a -> a -> a) -> NonEmpty a -> a
49+foldl1' f (a :| as) = foldl' f a as
src/Rel8/Query/Exists.hs+21−49
@@ -2,8 +2,8 @@
2
2
3module Rel8.Query.Exists
3module Rel8.Query.Exists
4 ( exists, inQuery
4 ( exists, inQuery
5− , whereExists, with, withBy
5+ , present, with, withBy
6− , whereNotExists, without, withoutBy
6+ , absent, without, withoutBy
7 )
7 )
8where
8where
9
9
@@ -11,84 +11,56 @@ where
11import Prelude hiding ( filter )
11import Prelude hiding ( filter )
12
12
13-- opaleye
13-- opaleye
14+import qualified Opaleye.Exists as Opaleye
14import qualified Opaleye.Operators as Opaleye
15import qualified Opaleye.Operators as Opaleye
15
16
16-- rel8
17-- rel8
17import Rel8.Expr ( Expr )
18import Rel8.Expr ( Expr )
19+import Rel8.Expr.Opaleye ( fromColumn, fromPrimExpr )
18import Rel8.Query ( Query )
20import Rel8.Query ( Query )
19import Rel8.Query.Filter ( filter )
21import Rel8.Query.Filter ( filter )
20−import Rel8.Query.Maybe ( optional )
21import Rel8.Query.Opaleye ( mapOpaleye )
22import Rel8.Query.Opaleye ( mapOpaleye )
22import Rel8.Table.Eq ( EqTable, (==:) )
23import Rel8.Table.Eq ( EqTable, (==:) )
23−import Rel8.Table.Maybe ( isJustTable )
24
24
25
25
26-- | Checks if a query returns at least one row.
26-- | Checks if a query returns at least one row.
27−--
28−-- >>> :{
29−-- mapM_ print =<< select c do
30−-- author <- each authorSchema
31−-- hasProjects <- exists do
32−-- project <- each projectSchema
33−-- where_ $ authorId author ==. projectAuthorId project
34−-- return (authorName author, hasProjects)
35−-- :}
36−-- ("Ollie",True)
37−-- ("Bryan O'Sullivan",True)
38−-- ("Emily Pillmore",False)
39exists :: Query a -> Query (Expr Bool)
27exists :: Query a -> Query (Expr Bool)
40−exists = fmap isJustTable . optional . whereExists
28+exists = fmap (fromPrimExpr . fromColumn) . mapOpaleye Opaleye.exists
41−-- FIXME: change this when b7aacc07c6392654cae439fc3b997620c3aa7a87 makes it
42−-- into a release of Opaleye
43
29
44
30
45inQuery :: EqTable a => a -> Query a -> Query (Expr Bool)
31inQuery :: EqTable a => a -> Query a -> Query (Expr Bool)
46inQuery a = exists . (>>= filter (a ==:))
32inQuery a = exists . (>>= filter (a ==:))
47
33
48
34
49−-- | Produce the empty query if the given query returns no rows. @whereExists@
35+-- | Produce the empty query if the given query returns no rows. @present@
50-- is equivalent to @WHERE EXISTS@ in SQL.
36-- is equivalent to @WHERE EXISTS@ in SQL.
51−--
52−-- >>> :{
53−-- select c do
54−-- author <- each authorSchema
55−-- whereExists do
56−-- project <- each projectSchema
57−-- where_ $ projectAuthorId project ==. authorId author
58−-- return $ authorName author
59−-- :}
60−-- ["Ollie","Bryan O'Sullivan"]
61−whereExists :: Query a -> Query ()
37+present :: Query a -> Query ()
62−whereExists = mapOpaleye Opaleye.restrictExists
38+present = mapOpaleye Opaleye.restrictExists
63−
39+
64−
40+
65−-- | Produce the empty query if the given query returns rows. @whereNotExists@
41+-- | Produce the empty query if the given query returns rows. @absent@
66-- is equivalent to @WHERE NOT EXISTS@ in SQL.
42-- is equivalent to @WHERE NOT EXISTS@ in SQL.
67−--
68−-- >>> :{
69−-- select c do
70−-- author <- each authorSchema
71−-- whereNotExists do
72−-- project <- each projectSchema
73−-- where_ $ projectAuthorId project ==. authorId author
74−-- return $ authorName author
75−-- :}
76−-- ["Emily Pillmore"]
77−whereNotExists :: Query a -> Query ()
43+absent :: Query a -> Query ()
78−whereNotExists = mapOpaleye Opaleye.restrictNotExists
44+absent = mapOpaleye Opaleye.restrictNotExists
79
45
80
46
47+-- | @with@ is similar to 'filter', but allows the predicate to be a full query.
48+--
49+-- @with f a = a <$ present (f a)@, but this form matches 'filter'.
81with :: (a -> Query b) -> a -> Query a
50with :: (a -> Query b) -> a -> Query a
82−with f a = a <$ whereExists (f a)
51+with f a = a <$ present (f a)
83
52
84
53
54+-- | Like @with@, but with a custom membership test.
85withBy :: (a -> b -> Expr Bool) -> Query b -> a -> Query a
55withBy :: (a -> b -> Expr Bool) -> Query b -> a -> Query a
86withBy predicate bs = with $ \a -> bs >>= filter (predicate a)
56withBy predicate bs = with $ \a -> bs >>= filter (predicate a)
87
57
88
58
59+-- | Filter rows where @a -> Query b@ yields no rows.
89without :: (a -> Query b) -> a -> Query a
60without :: (a -> Query b) -> a -> Query a
90−without f a = a <$ whereNotExists (f a)
61+without f a = a <$ absent (f a)
91
62
92
63
64+-- | Like @without@, but with a custom membership test.
93withoutBy :: (a -> b -> Expr Bool) -> Query b -> a -> Query a
65withoutBy :: (a -> b -> Expr Bool) -> Query b -> a -> Query a
94withoutBy predicate bs = without $ \a -> bs >>= filter (predicate a)
66withoutBy predicate bs = without $ \a -> bs >>= filter (predicate a)
src/Rel8/Query/Filter.hs−11
@@ -24,23 +24,12 @@ import Rel8.Query.Opaleye ( fromOpaleye )
24-- return @x@ unchanged when @f x@ is @True@. This is similar to
24-- return @x@ unchanged when @f x@ is @True@. This is similar to
25-- 'Control.Monad.guard', but as the predicate is separate from the argument,
25-- 'Control.Monad.guard', but as the predicate is separate from the argument,
26-- it is easy to use in a pipeline of 'Query' transformations.
26-- it is easy to use in a pipeline of 'Query' transformations.
27−--
28−-- >>> select c $ values [ lit x | x <- [ 1..5 :: Int32 ] ] >>= filter (>. 3)
29−-- [4,5]
30filter :: (a -> Expr Bool) -> a -> Query a
27filter :: (a -> Expr Bool) -> a -> Query a
31filter f a = a <$ where_ (f a)
28filter f a = a <$ where_ (f a)
32
29
33
30
34-- | Drop any rows that don't match a predicate. @where_ expr@ is equivalent
31-- | Drop any rows that don't match a predicate. @where_ expr@ is equivalent
35-- to the SQL @WHERE expr@.
32-- to the SQL @WHERE expr@.
36−--
37−-- >>> :{
38−-- select c $ do
39−-- x <- values [ lit x | x <- [ 1..5 :: Int32 ] ]
40−-- where_ $ x >. lit 2
41−-- return x
42−-- :}
43−-- [3,4,5]
44where_ :: Expr Bool -> Query ()
33where_ :: Expr Bool -> Query ()
45where_ condition =
34where_ condition =
46 fromOpaleye $ lmap (\_ -> toColumn $ toPrimExpr condition) Opaleye.restrict
35 fromOpaleye $ lmap (\_ -> toColumn $ toPrimExpr condition) Opaleye.restrict
src/Rel8/Query/Indexed.hsnew file+21
@@ -0,0 +1,21 @@
1+module Rel8.Query.Indexed
2+ ( indexed
3+ )
4+where
5+
6+-- base
7+import Control.Applicative ( liftA2 )
8+import Data.Int ( Int64 )
9+import Prelude
10+
11+-- rel8
12+import Rel8.Expr ( Expr )
13+import Rel8.Expr.Window ( rowNumber )
14+import Rel8.Query ( Query )
15+import Rel8.Query.Window ( window )
16+import Rel8.Table.Window ( currentRow )
17+
18+
19+-- | Pair each row of a query with its index within the query.
20+indexed :: Query a -> Query (Expr Int64, a)
21+indexed = window (liftA2 (,) (subtract 1 <$> rowNumber) currentRow)
src/Rel8/Query/Limit.hs−6
@@ -17,17 +17,11 @@ import Rel8.Query.Opaleye ( mapOpaleye )
17
17
18-- | @limit n@ select at most @n@ rows from a query. @limit n@ is equivalent
18-- | @limit n@ select at most @n@ rows from a query. @limit n@ is equivalent
19-- to the SQL @LIMIT n@.
19-- to the SQL @LIMIT n@.
20−--
21−-- >>> select c $ limit 3 $ values [ lit x | x <- [ 1..5 :: Int32 ] ]
22−-- [1,2,3]
23limit :: Word -> Query a -> Query a
20limit :: Word -> Query a -> Query a
24limit = mapOpaleye . Opaleye.limit . fromIntegral
21limit = mapOpaleye . Opaleye.limit . fromIntegral
25
22
26
23
27-- | @offset n@ drops the first @n@ rows from a query. @offset n@ is equivalent
24-- | @offset n@ drops the first @n@ rows from a query. @offset n@ is equivalent
28-- to the SQL @OFFSET n@.
25-- to the SQL @OFFSET n@.
29−--
30−-- >>> select c $ offset 3 $ values [ lit x | x <- [ 1..5 :: Int32 ] ]
31−-- [4,5]
32offset :: Word -> Query a -> Query a
26offset :: Word -> Query a -> Query a
33offset = mapOpaleye . Opaleye.offset . fromIntegral
27offset = mapOpaleye . Opaleye.offset . fromIntegral
src/Rel8/Query/List.hs+93−14
@@ -1,23 +1,58 @@
1{-# language FlexibleContexts #-}
1{-# language FlexibleContexts #-}
2+{-# language GADTs #-}
3+{-# language NamedFieldPuns #-}
2
4
3module Rel8.Query.List
5module Rel8.Query.List
4 ( many, some
6 ( many, some
7+ , manyExpr, someExpr
8+ , catListTable, catNonEmptyTable
9+ , catList, catNonEmpty
5 )
10 )
6where
11where
7
12
8-- base
13-- base
14+import Data.Functor.Identity ( runIdentity )
15+import Data.List.NonEmpty ( NonEmpty )
9import Prelude
16import Prelude
10
17
18+-- opaleye
19+import qualified Opaleye.Internal.HaskellDB.PrimQuery as Opaleye
20+
11-- rel8
21-- rel8
12import Rel8.Expr ( Expr )
22import Rel8.Expr ( Expr )
23+import Rel8.Expr.Aggregate ( listAggExpr, nonEmptyAggExpr )
24+import Rel8.Expr.Opaleye ( mapPrimExpr )
13import Rel8.Query ( Query )
25import Rel8.Query ( Query )
14import Rel8.Query.Aggregate ( aggregate )
26import Rel8.Query.Aggregate ( aggregate )
15import Rel8.Query.Maybe ( optional )
27import Rel8.Query.Maybe ( optional )
16−import Rel8.Table ( Table )
28+import Rel8.Query.Rebind ( rebind )
29+import Rel8.Schema.HTable.Vectorize ( hunvectorize )
30+import Rel8.Schema.Null ( Sql, Unnullify )
31+import Rel8.Schema.Spec ( Spec( Spec, info ) )
32+import Rel8.Table ( Table, fromColumns )
33+import Rel8.Table.Cols ( toCols )
17import Rel8.Table.Aggregate ( listAgg, nonEmptyAgg )
34import Rel8.Table.Aggregate ( listAgg, nonEmptyAgg )
18−import Rel8.Table.List ( ListTable )
35+import Rel8.Table.List ( ListTable( ListTable ) )
19import Rel8.Table.Maybe ( maybeTable )
36import Rel8.Table.Maybe ( maybeTable )
20−import Rel8.Table.NonEmpty ( NonEmptyTable )
37+import Rel8.Table.NonEmpty ( NonEmptyTable( NonEmptyTable ) )
38+import Rel8.Type ( DBType, typeInformation )
39+import Rel8.Type.Array ( extractArrayElement )
40+import Rel8.Type.Information ( TypeInformation )
41+
42+
43+-- | Aggregate a 'Query' into a 'ListTable'. If the supplied query returns 0
44+-- rows, this function will produce a 'Query' that returns one row containing
45+-- the empty @ListTable@. If the supplied @Query@ does return rows, @many@ will
46+-- return exactly one row, with a @ListTable@ collecting all returned rows.
47+--
48+-- @many@ is analogous to 'Control.Applicative.many' from
49+-- @Control.Applicative@.
50+many :: Table Expr a => Query a -> Query (ListTable Expr a)
51+many =
52+ fmap (maybeTable mempty (\(ListTable a) -> ListTable a)) .
53+ optional .
54+ aggregate .
55+ fmap (listAgg . toCols)
21
56
22
57
23-- | Aggregate a 'Query' into a 'NonEmptyTable'. If the supplied query returns
58-- | Aggregate a 'Query' into a 'NonEmptyTable'. If the supplied query returns
@@ -28,16 +63,60 @@ import Rel8.Table.NonEmpty ( NonEmptyTable )
28--
63--
29-- @some@ is analogous to 'Control.Applicative.some' from
64-- @some@ is analogous to 'Control.Applicative.some' from
30-- @Control.Applicative@.
65-- @Control.Applicative@.
31−some :: Table Expr a => Query a -> Query (NonEmptyTable a)
66+some :: Table Expr a => Query a -> Query (NonEmptyTable Expr a)
67+some =
68+ fmap (\(NonEmptyTable a) -> NonEmptyTable a) .
69+ aggregate .
32−some = aggregate . fmap nonEmptyAgg
70+ fmap (nonEmptyAgg . toCols)
33
71
34
72
35−-- | Aggregate a 'Query' into a 'ListTable'. If the supplied query returns 0
73+-- | A version of 'many' specialised to single expressions.
36−-- rows, this function will produce a 'Query' that returns one row containing
74+manyExpr :: Sql DBType a => Query (Expr a) -> Query (Expr [a])
37−-- the empty @ListTable@. If the supplied @Query@ does return rows, @many@ will
38−-- return exactly one row, with a @ListTable@ collecting all returned rows.
39−--
40−-- @many@ is analogous to 'Control.Applicative.many' from
41−-- @Control.Applicative@.
42−many :: Table Expr a => Query a -> Query (ListTable a)
43−many = fmap (maybeTable mempty id) . optional . aggregate . fmap listAgg
75+manyExpr = fmap (maybeTable mempty id) . optional . aggregate . fmap listAggExpr
76+
77+
78+-- | A version of 'many' specialised to single expressions.
79+someExpr :: Sql DBType a => Query (Expr a) -> Query (Expr (NonEmpty a))
80+someExpr = aggregate . fmap nonEmptyAggExpr
81+
82+
83+-- | Expand a 'ListTable' into a 'Query', where each row in the query is an
84+-- element of the given @ListTable@.
85+--
86+-- @catListTable@ is an inverse to 'many'.
87+catListTable :: Table Expr a => ListTable Expr a -> Query a
88+catListTable (ListTable as) =
89+ rebind "unnest" $ fromColumns $ runIdentity $
90+ hunvectorize (\Spec {info} -> pure . sunnest info) as
91+
92+
93+-- | Expand a 'NonEmptyTable' into a 'Query', where each row in the query is an
94+-- element of the given @NonEmptyTable@.
95+--
96+-- @catNonEmptyTable@ is an inverse to 'some'.
97+catNonEmptyTable :: Table Expr a => NonEmptyTable Expr a -> Query a
98+catNonEmptyTable (NonEmptyTable as) =
99+ rebind "unnest" $ fromColumns $ runIdentity $
100+ hunvectorize (\Spec {info} -> pure . sunnest info) as
101+
102+
103+-- | Expand an expression that contains a list into a 'Query', where each row
104+-- in the query is an element of the given list.
105+--
106+-- @catList@ is an inverse to 'manyExpr'.
107+catList :: Sql DBType a => Expr [a] -> Query (Expr a)
108+catList = rebind "unnest" . sunnest typeInformation
109+
110+
111+-- | Expand an expression that contains a non-empty list into a 'Query', where
112+-- each row in the query is an element of the given list.
113+--
114+-- @catNonEmpty@ is an inverse to 'someExpr'.
115+catNonEmpty :: Sql DBType a => Expr (NonEmpty a) -> Query (Expr a)
116+catNonEmpty = rebind "unnest" . sunnest typeInformation
117+
118+
119+sunnest :: TypeInformation (Unnullify a) -> Expr (list a) -> Expr a
120+sunnest info = mapPrimExpr $
121+ extractArrayElement info .
122+ Opaleye.UnExpr (Opaleye.UnOpOther "UNNEST")
src/Rel8/Query/Maybe.hs+33−101
@@ -1,7 +1,10 @@
1+{-# language GADTs #-}
2+{-# language LambdaCase #-}
3+{-# language NamedFieldPuns #-}
4+
1module Rel8.Query.Maybe
5module Rel8.Query.Maybe
2 ( optional
6 ( optional
3 , catMaybeTable
7 , catMaybeTable
4− , bindMaybeTable
5 , traverseMaybeTable
8 , traverseMaybeTable
6 )
9 )
7where
10where
@@ -9,35 +12,32 @@ where
9-- base
12-- base
10import Prelude
13import Prelude
11
14
15+-- comonad
16+import Control.Comonad ( extract )
17+
12-- opaleye
18-- opaleye
13−import qualified Opaleye.Internal.PackMap as Opaleye
19+import qualified Opaleye.Internal.MaybeFields as Opaleye
14−import qualified Opaleye.Internal.PrimQuery as Opaleye
15−import qualified Opaleye.Internal.QueryArr as Opaleye
16−import qualified Opaleye.Internal.Tag as Opaleye
17−import qualified Opaleye.Internal.Unpackspec as Opaleye
18
20
19-- rel8
21-- rel8
20−import Rel8.Expr.Bool ( true )
22+import Rel8.Expr ( Expr )
21import Rel8.Expr.Eq ( (==.) )
23import Rel8.Expr.Eq ( (==.) )
22−import Rel8.Expr.Opaleye ( toPrimExpr )
24+import Rel8.Expr.Opaleye ( fromColumn, fromPrimExpr )
23import Rel8.Query ( Query )
25import Rel8.Query ( Query )
24import Rel8.Query.Filter ( where_ )
26import Rel8.Query.Filter ( where_ )
25import Rel8.Query.Opaleye ( mapOpaleye )
27import Rel8.Query.Opaleye ( mapOpaleye )
26−import Rel8.Table.Maybe ( MaybeTable( MaybeTable ), isJustTable )
28+import Rel8.Table.Maybe ( MaybeTable(..), isJustTable )
27−import Rel8.Table.Opaleye ( unpackspec )
28
29
29
30
31+-- | Convert a query that might return zero rows to a query that always returns
32+-- at least one row.
33+--
34+-- To speak in more concrete terms, 'optional' is most useful to write @LEFT
35+-- JOIN@s.
30−optional :: Query a -> Query (MaybeTable a)
36+optional :: Query a -> Query (MaybeTable Expr a)
31−optional = mapOpaleye $ Opaleye.QueryArr . go
37+optional = mapOpaleye $ Opaleye.optionalInternal $ \tag a -> MaybeTable
32− where
38+ { tag = fromPrimExpr $ fromColumn tag
33− go query (i, left, tag) = (MaybeTable t' a, join, Opaleye.next tag')
39+ , just = pure a
34− where
40+ }
35− (MaybeTable t a, right, tag') =
36− Opaleye.runSimpleQueryArr (pure <$> query) (i, tag)
37− (t', bindings) = Opaleye.run $
38− Opaleye.runUnpackspec unpackspec (Opaleye.extractAttr "maybe" tag') t
39− join = Opaleye.Join Opaleye.LeftJoin condition [] bindings left right
40− condition = toPrimExpr true
41
41
42
42
43-- | Filter out 'MaybeTable's, returning only the tables that are not-null.
43-- | Filter out 'MaybeTable's, returning only the tables that are not-null.
@@ -45,92 +45,24 @@ optional = mapOpaleye $ Opaleye.QueryArr . go
45-- This operation can be used to "undo" the effect of 'optional', which
45-- This operation can be used to "undo" the effect of 'optional', which
46-- operationally is like turning a @LEFT JOIN@ back into a full @JOIN@. You
46-- operationally is like turning a @LEFT JOIN@ back into a full @JOIN@. You
47-- can think of this as analogous to 'Data.Maybe.catMaybes'.
47-- can think of this as analogous to 'Data.Maybe.catMaybes'.
48−--
49−-- To see this in action, first consider the following 'optional' query:
50−--
51−-- >>> :{
52−-- select c $ do
53−-- author <- each authorSchema
54−-- maybeRel8 <- optional $
55−-- each projectSchema
56−-- >>= filter (\p -> projectAuthorId p ==. authorId author)
57−-- >>= filter (\p -> projectName p ==. "rel8")
58−-- return (authorName author, projectName <$> maybeRel8)
59−-- :}
60−-- [("Ollie",Just "rel8"),("Bryan O'Sullivan",Nothing),("Emily Pillmore",Nothing)]
61−--
62−-- Here @optional@ is acting as a @LEFT JOIN@. We can turn this into a proper
63−-- join by using @catMaybeTable@ to filter out rows where the join failed:
64−--
65−-- >>> :{
66−-- select c $ do
67−-- author <- each authorSchema
68−-- maybeRel8 <- optional $
69−-- each projectSchema
70−-- >>= filter (\p -> projectAuthorId p ==. authorId author)
71−-- >>= filter (\p -> projectName p ==. "rel8")
72−-- rel8 <- catMaybeTable maybeRel8
73−-- return (authorName author, projectName rel8)
74−-- :}
75−-- [("Ollie","rel8")]
76−catMaybeTable :: MaybeTable a -> Query a
48+catMaybeTable :: MaybeTable Expr a -> Query a
77catMaybeTable ma@(MaybeTable _ a) = do
49catMaybeTable ma@(MaybeTable _ a) = do
78 where_ $ isJustTable ma
50 where_ $ isJustTable ma
79− pure a
51+ pure (extract a)
80−
81−
82−-- | @bindMaybeTable f x@ is similar to the monadic bind (@>>=@) operation. It
83−-- allows you to "extend" an optional query with another query. If either the
84−-- input or output are 'noTable', then the result is 'noTable'.
85−--
86−-- This is similar to 'traverseMaybeTable', followed by a @join@ on the
87−-- resulting @MaybeTable@s.
88−--
89−-- >>> select c $ bindMaybeTable (optional . values . pure . not_) =<< optional (values [lit True])
90−-- [Just False]
91−--
92−-- >>> select c $ bindMaybeTable (\_ -> return (noTable :: MaybeTable (Expr Bool))) =<< optional (values [lit True])
93−-- [Nothing]
94−--
95−-- >>> select c $ bindMaybeTable (optional . values . pure . not_) =<< return (noTable :: MaybeTable (Expr Bool))
96−-- [Nothing]
97−bindMaybeTable :: Monad m
98− => (a -> m (MaybeTable b)) -> MaybeTable a -> m (MaybeTable b)
99−bindMaybeTable query (MaybeTable input a) = do
100− MaybeTable output b <- query a
101− pure $ MaybeTable (input <> output) b
102
52
103
53
104-- | Extend an optional query with another query. This is useful if you want
54-- | Extend an optional query with another query. This is useful if you want
105-- to step through multiple @LEFT JOINs@.
55-- to step through multiple @LEFT JOINs@.
106--
56--
107-- Note that @traverseMaybeTable@ takes a @a -> Query b@ function, which means
57-- Note that @traverseMaybeTable@ takes a @a -> Query b@ function, which means
108−-- you also have the ability to "expand" one row into multiple rows.
58+-- you also have the ability to "expand" one row into multiple rows. If the
109−--
110−-- >>> :{
111−-- duplicate :: Expr Bool -> Query (Expr Bool)
112−-- duplicate x = unionAll (return x) (return x)
113−-- :}
114−--
115−-- >>> select c $ traverseMaybeTable duplicate =<< optional (values [lit True])
116−-- [Just True,Just True]
117−--
118−-- Note that if the @a -> Query b@ function returns no rows, then the resulting
59+-- @a -> Query b@ function returns no rows, then the resulting query will also
119−-- query will also have no rows:
120−--
121−-- >>> select c $ traverseMaybeTable (limit 0 . pure) =<< optional (values [lit True])
122−-- []
123−--
124−-- However, regardless of the given @a -> Query b@ function, if the input is
60+-- have no rows. However, regardless of the given @a -> Query b@ function, if
125−-- @noTable@, you will always get exactly one @noTable@ back:
61+-- the input is @nothingTable@, you will always get exactly one @nothingTable@
126−--
62+-- back.
127−-- >>> select c $ traverseMaybeTable duplicate (noTable :: MaybeTable (Expr Bool))
128−-- [Nothing]
129−--
130−-- >>> select c $ traverseMaybeTable (limit 0 . pure) (noTable :: MaybeTable (Expr Bool))
131−-- [Nothing]
132−traverseMaybeTable :: (a -> Query b) -> MaybeTable a -> Query (MaybeTable b)
63+traverseMaybeTable :: (a -> Query b) -> MaybeTable Expr a -> Query (MaybeTable Expr b)
133traverseMaybeTable query ma@(MaybeTable input _) = do
64traverseMaybeTable query ma@(MaybeTable input _) = do
134− MaybeTable output b <- optional (query =<< catMaybeTable ma)
65+ optional (query =<< catMaybeTable ma) >>= \case
66+ MaybeTable output b -> do
135− where_ $ output ==. input
67+ where_ $ output ==. input
136− pure $ MaybeTable input b
68+ pure $ MaybeTable input b
src/Rel8/Query/Null.hs+18−18
@@ -1,5 +1,8 @@
1+{-# language FlexibleContexts #-}
2+
1module Rel8.Query.Null
3module Rel8.Query.Null
2− ( catNullable
4+ ( catNull
5+ , catNullTable
3 )
6 )
4where
7where
5
8
@@ -9,6 +12,8 @@ import Prelude
9-- rel8
12-- rel8
10import Rel8.Expr ( Expr )
13import Rel8.Expr ( Expr )
11import Rel8.Expr.Null ( isNonNull, unsafeUnnullify )
14import Rel8.Expr.Null ( isNonNull, unsafeUnnullify )
15+import Rel8.Table ( Table )
16+import Rel8.Table.Null ( NullTable, isNonNullTable, unsafeUnnullifyTable )
12import Rel8.Query ( Query )
17import Rel8.Query ( Query )
13import Rel8.Query.Filter ( where_ )
18import Rel8.Query.Filter ( where_ )
14
19
@@ -17,22 +22,17 @@ import Rel8.Query.Filter ( where_ )
17-- @null@s.
22-- @null@s.
18--
23--
19-- Corresponds to 'Data.Maybe.catMaybes'.
24-- Corresponds to 'Data.Maybe.catMaybes'.
20−--
21−-- >>> select c $ pure (nullExpr :: Expr (Maybe Bool))
22−-- [Nothing]
23−--
24−-- >>> select c $ catNullable (nullExpr :: Expr (Maybe Bool))
25−-- []
26−--
27−-- >>> select c $ catNullable (lit (Just True))
28−-- [True]
29−--
30−-- Notice how in the last example a @Bool@ is returned (rather than @Maybe
31−-- Bool@):
32−--
33−-- >>> :t catNullable (lit (Just True))
34−-- catMaybe (lit (Just True)) :: Query (Expr Bool)
35−catNullable :: Expr (Maybe a) -> Query (Expr a)
25+catNull :: Expr (Maybe a) -> Query (Expr a)
36−catNullable a = do
26+catNull a = do
37 where_ $ isNonNull a
27 where_ $ isNonNull a
38 pure $ unsafeUnnullify a
28 pure $ unsafeUnnullify a
29+
30+
31+-- | Filter a 'Query' that might return @nullTable@ to a 'Query' without any
32+-- @nullTable@s.
33+--
34+-- Corresponds to 'Data.Maybe.catMaybes'.
35+catNullTable :: Table Expr a => NullTable Expr a -> Query a
36+catNullTable a = do
37+ where_ $ isNonNullTable a
38+ pure $ unsafeUnnullifyTable a
src/Rel8/Query/Opaleye.hs+41−5
@@ -1,34 +1,70 @@
1+{-# language TupleSections #-}
2+
1module Rel8.Query.Opaleye
3module Rel8.Query.Opaleye
2 ( fromOpaleye
4 ( fromOpaleye
3 , toOpaleye
5 , toOpaleye
4 , mapOpaleye
6 , mapOpaleye
5 , zipOpaleyeWith
7 , zipOpaleyeWith
8+ , unsafePeekQuery
6 )
9 )
7where
10where
8
11
9-- base
12-- base
13+import Control.Applicative ( liftA2 )
10import Prelude
14import Prelude
11
15
12-- opaleye
16-- opaleye
13−import qualified Opaleye.Select as Opaleye
17+import qualified Opaleye.Internal.QueryArr as Opaleye
18+import qualified Opaleye.Internal.Tag as Opaleye
14
19
15-- rel8
20-- rel8
16import {-# SOURCE #-} Rel8.Query ( Query( Query ) )
21import {-# SOURCE #-} Rel8.Query ( Query( Query ) )
17
22
18
23
19fromOpaleye :: Opaleye.Select a -> Query a
24fromOpaleye :: Opaleye.Select a -> Query a
20−fromOpaleye = Query
25+fromOpaleye = Query . pure . fmap pure
21
26
22
27
23toOpaleye :: Query a -> Opaleye.Select a
28toOpaleye :: Query a -> Opaleye.Select a
24−toOpaleye (Query a) = a
29+toOpaleye (Query a) = snd <$> a mempty
25
30
26
31
27mapOpaleye :: (Opaleye.Select a -> Opaleye.Select b) -> Query a -> Query b
32mapOpaleye :: (Opaleye.Select a -> Opaleye.Select b) -> Query a -> Query b
28−mapOpaleye f = fromOpaleye . f . toOpaleye
33+mapOpaleye f (Query a) = Query (fmap (mapping f) a)
29
34
30
35
31zipOpaleyeWith :: ()
36zipOpaleyeWith :: ()
32 => (Opaleye.Select a -> Opaleye.Select b -> Opaleye.Select c)
37 => (Opaleye.Select a -> Opaleye.Select b -> Opaleye.Select c)
33 -> Query a -> Query b -> Query c
38 -> Query a -> Query b -> Query c
34−zipOpaleyeWith f a b = fromOpaleye $ f (toOpaleye a) (toOpaleye b)
39+zipOpaleyeWith f (Query a) (Query b) = Query $ liftA2 (zipping f) a b
40+
41+
42+unsafePeekQuery :: Query a -> a
43+unsafePeekQuery (Query q) = case q mempty of
44+ f -> case Opaleye.runStateQueryArr f () Opaleye.start of
45+ ((_, a), _, _) -> a
46+
47+
48+mapping :: ()
49+ => (Opaleye.Select a -> Opaleye.Select b)
50+ -> Opaleye.Select (m, a) -> Opaleye.Select (m, b)
51+mapping f q = Opaleye.stateQueryArr $ \_ tag ->
52+ let
53+ ((m, _), _, _) = Opaleye.runStateQueryArr q () tag
54+ q' = (m,) <$> f (snd <$> q)
55+ in
56+ Opaleye.runStateQueryArr q' () tag
57+
58+
59+zipping :: Semigroup m
60+ => (Opaleye.Select a -> Opaleye.Select b -> Opaleye.Select c)
61+ -> Opaleye.Select (m, a) -> Opaleye.Select (m, b) -> Opaleye.Select (m, c)
62+zipping f q q' =
63+ Opaleye.stateQueryArr $ \_ tag ->
64+ let
65+ ((m, _), _, _) = Opaleye.runStateQueryArr q () tag
66+ ((m', _), _, _) = Opaleye.runStateQueryArr q' () tag
67+ m'' = m <> m'
68+ q'' = (m'',) <$> f (snd <$> q) (snd <$> q')
69+ in
70+ Opaleye.runStateQueryArr q'' () tag
src/Rel8/Query/Optimize.hsdeleted−200
@@ -1,200 +0,0 @@
1−{-# language ApplicativeDo #-}
2−{-# language LambdaCase #-}
3−
4−{-# options -fno-warn-name-shadowing #-}
5−
6−module Rel8.Query.Optimize
7− ( optimize
8− )
9−where
10−
11−-- base
12−import Control.Applicative
13−import Data.Functor.Identity
14−import Prelude
15−
16−-- opaleye
17−import Opaleye.Internal.HaskellDB.PrimQuery
18−import Opaleye.Internal.PrimQuery
19−
20−
21−optimize :: PrimQuery' a -> PrimQuery' a
22−optimize =
23− transformOf primQuery optimisePredicates
24−
25−
26−primQuery
27− :: Applicative f
28− => ( PrimQuery' a -> f ( PrimQuery' a ) ) -> PrimQuery' a -> f ( PrimQuery' a )
29−primQuery f = \case
30− Aggregate bindingsAndPrimExpr primQuery -> do
31− primQuery <- f primQuery
32−
33− return ( Aggregate bindingsAndPrimExpr primQuery )
34−
35− DistinctOnOrderBy maybePrimExprs orderExprs primQuery -> do
36− primQuery <- f primQuery
37−
38− return ( DistinctOnOrderBy maybePrimExprs orderExprs primQuery )
39−
40− Limit limitOp primQuery -> do
41− primQuery <- f primQuery
42−
43− return ( Limit limitOp primQuery )
44−
45− Join joinType primExpr bindingsA bindingsB primQueryA primQueryB -> do
46− primQueryA <- f primQueryA
47− primQueryB <- f primQueryB
48−
49− return ( Join joinType primExpr bindingsA bindingsB primQueryA primQueryB )
50−
51− Exists bool primQueryA primQueryB -> do
52− primQueryA <- f primQueryA
53− primQueryB <- f primQueryB
54−
55− return ( Exists bool primQueryA primQueryB )
56−
57− Binary binOp primQueries -> do
58− primQueries <- both f primQueries
59−
60− return ( Binary binOp primQueries )
61−
62− Label label primQuery -> do
63− primQuery <- f primQuery
64−
65− return ( Label label primQuery )
66−
67− other ->
68− pure other
69−
70−
71−optimisePredicates :: PrimQuery' a -> PrimQuery' a
72−optimisePredicates = \case
73− Join joinType predicate bindingsA bindingsB primQueryA primQueryB ->
74− Join joinType ( nullIsFalse predicate ) bindingsA bindingsB primQueryA primQueryB
75−
76− other ->
77− other
78−
79−
80−nullIsFalse :: PrimExpr -> PrimExpr
81−nullIsFalse =
82− rewriteOf primExprs simplifyCaseAnalysis
83−
84− where
85−
86− simplifyCaseAnalysis = \case
87− CaseExpr [ ( UnExpr OpIsNull _, ConstExpr ( BoolLit False ) ) ] notNullBranch ->
88− Just notNullBranch
89−
90− CaseExpr [ ( UnExpr OpIsNull x, UnExpr OpIsNull y ) ] notNullBranch ->
91− Just
92− ( BinExpr
93− (:||)
94− ( BinExpr (:&&) ( UnExpr OpIsNull x ) ( UnExpr OpIsNull y ) )
95− notNullBranch
96− )
97−
98− _ ->
99− Nothing
100−
101−
102−
103−-- | Traverse all immediate 'PrimExpr's
104−primExprs :: Applicative f => ( PrimExpr -> f PrimExpr ) -> PrimExpr -> f PrimExpr
105−primExprs f = \case
106− AttrExpr ( Symbol string tag ) ->
107− pure ( AttrExpr ( Symbol string tag ) )
108−
109− BaseTableAttrExpr attribute ->
110− pure ( BaseTableAttrExpr attribute )
111−
112− CompositeExpr primExpr attribute -> do
113− primExpr <- f primExpr
114−
115− return ( CompositeExpr primExpr attribute )
116−
117− BinExpr binOp a b -> do
118− a <- f a
119− b <- f b
120−
121− return ( BinExpr binOp a b )
122−
123− UnExpr unOp primExpr -> do
124− primExpr <- f primExpr
125−
126− return ( UnExpr unOp primExpr )
127−
128− AggrExpr aggrDistinct aggrOp primExpr orderExprs -> do
129− aggrOp <- aggrOpPrimExprs f aggrOp
130− primExpr <- f primExpr
131− orderExprs <- traverse ( orderExprPrimExprs f ) orderExprs
132−
133− return ( AggrExpr aggrDistinct aggrOp primExpr orderExprs )
134−
135− ConstExpr l ->
136− pure ( ConstExpr l )
137−
138− CaseExpr cases def -> do
139− cases <- traverse ( both f ) cases
140− def <- f def
141−
142− return ( CaseExpr cases def )
143−
144− other ->
145− pure other
146−
147−
148−
149−aggrOpPrimExprs :: Applicative f => ( PrimExpr -> f PrimExpr ) -> AggrOp -> f AggrOp
150−aggrOpPrimExprs f = \case
151− AggrStringAggr primExpr -> do
152− primExpr <- f primExpr
153−
154− return ( AggrStringAggr primExpr )
155−
156− other ->
157− pure other
158−
159−
160−orderExprPrimExprs :: Applicative f => ( PrimExpr -> f PrimExpr ) -> OrderExpr -> f OrderExpr
161−orderExprPrimExprs f ( OrderExpr orderOp primExpr ) = do
162− primExpr <- f primExpr
163−
164− return ( OrderExpr orderOp primExpr )
165−
166−
167−-- | Traverse both sides of a homogeneous tuple.
168−both :: Applicative f => ( t -> f b ) -> ( t, t ) -> f ( b, b )
169−both f ( a,b ) =
170− liftA2 (,) ( f a ) ( f b )
171−
172−
173−rewriteOf
174− :: ( ( a -> Identity a ) -> a -> Identity a )
175− -> ( a -> Maybe a ) -> a -> a
176−rewriteOf l f =
177− go where
178−
179− go = transformOf l ( \x -> maybe x go ( f x ) )
180−
181−
182−transformOf
183− :: ( ( a -> Identity a ) -> a -> Identity a )
184− -> ( a -> a )
185− -> a
186− -> a
187−{-# inline transformOf #-}
188−transformOf l f = go where
189−
190− go =
191− f . over l go
192−
193−
194−over
195− :: ( ( s -> Identity t ) -> a -> Identity b )
196− -> ( s -> t )
197− -> a
198− -> b
199−over l f =
200− runIdentity . l (Identity . f)
src/Rel8/Query/Order.hs+1
@@ -15,5 +15,6 @@ import Rel8.Query ( Query )
15import Rel8.Query.Opaleye ( mapOpaleye )
15import Rel8.Query.Opaleye ( mapOpaleye )
16
16
17
17
18+-- | Order the rows returned by a query.
18orderBy :: Order a -> Query a -> Query a
19orderBy :: Order a -> Query a -> Query a
19orderBy (Order o) = mapOpaleye (Opaleye.orderBy o)
20orderBy (Order o) = mapOpaleye (Opaleye.orderBy o)
src/Rel8/Query/Rebind.hsnew file+27
@@ -0,0 +1,27 @@
1+{-# language FlexibleContexts #-}
2+
3+module Rel8.Query.Rebind
4+ ( rebind
5+ )
6+where
7+
8+-- base
9+import Prelude
10+import Control.Arrow ((<<<))
11+
12+-- opaleye
13+import qualified Opaleye.Internal.Rebind as Opaleye
14+
15+-- rel8
16+import Rel8.Expr ( Expr )
17+import Rel8.Query ( Query )
18+import Rel8.Table ( Table )
19+import Rel8.Table.Opaleye ( unpackspec )
20+import Rel8.Query.Opaleye (fromOpaleye)
21+
22+
23+-- | 'rebind' takes a variable name, some expressions, and binds each of them
24+-- to a new variable in the SQL. The @a@ returned consists only of these
25+-- variables. It's essentially a @let@ binding for Postgres expressions.
26+rebind :: Table Expr a => String -> a -> Query a
27+rebind prefix a = fromOpaleye (Opaleye.rebindExplicitPrefix prefix unpackspec <<< pure a)
src/Rel8/Query/SQL.hs+5−59
@@ -1,75 +1,21 @@
1{-# language FlexibleContexts #-}
1{-# language FlexibleContexts #-}
2−{-# language TypeFamilies #-}
2+{-# language MonoLocalBinds #-}
3−{-# language ViewPatterns #-}
4
3
5module Rel8.Query.SQL
4module Rel8.Query.SQL
6 ( showQuery
5 ( showQuery
7− , sqlForQuery, sqlForQueryWithNames
8 )
6 )
9where
7where
10
8
11-- base
9-- base
12−import Data.Foldable ( fold )
13−import Data.Functor.Const ( Const( Const ), getConst )
14−import Data.Void ( Void )
15import Prelude
10import Prelude
16
11
17−-- opaleye
18−import qualified Opaleye.Internal.HaskellDB.Sql as Opaleye
19−import qualified Opaleye.Internal.PrimQuery as Opaleye
20−import qualified Opaleye.Internal.Print as Opaleye
21−import qualified Opaleye.Internal.Optimize as Opaleye
22−import qualified Opaleye.Internal.QueryArr as Opaleye hiding ( Select )
23−import qualified Opaleye.Internal.Sql as Opaleye
24−
25-- rel8
12-- rel8
26import Rel8.Expr ( Expr )
13import Rel8.Expr ( Expr )
27−import Rel8.Expr.Opaleye ( toPrimExpr )
28import Rel8.Query ( Query )
14import Rel8.Query ( Query )
29−import Rel8.Query.Opaleye ( toOpaleye )
15+import Rel8.Statement.Select ( ppSelect )
30−import qualified Rel8.Query.Optimize as Rel8 ( optimize )
31−import Rel8.Schema.Context ( Col'(..), Name( Name ) )
32−import Rel8.Schema.HTable ( htabulateA, hfield )
33−import Rel8.Table ( Table, toColumns )
34−import Rel8.Table.Name ( namesFromLabels )
16+import Rel8.Table ( Table )
35−import Rel8.Table.Recontextualize ( Selects )
36
17
37
18
38−-- | Convert a query to a 'String' containing the query as a @SELECT@
19+-- | Convert a 'Query' to a 'String' containing a @SELECT@ statement.
39−-- statement.
40showQuery :: Table Expr a => Query a -> String
20showQuery :: Table Expr a => Query a -> String
41−showQuery = fold . sqlForQuery
21+showQuery = show . ppSelect
42−
43−
44−sqlForQuery :: Table Expr a
45− => Query a -> Maybe String
46−sqlForQuery = sqlForQueryWithNames namesFromLabels . fmap toColumns
47−
48−
49−sqlForQueryWithNames :: Selects names exprs
50− => names -> Query exprs -> Maybe String
51−sqlForQueryWithNames names query =
52− show . Opaleye.ppSql . selectFrom names exprs <$> optimize primQuery
53− where
54− (exprs, primQuery, _) =
55− Opaleye.runSimpleQueryArrStart (toOpaleye query) ()
56−
57−
58−optimize :: Opaleye.PrimQuery' a -> Maybe (Opaleye.PrimQuery' Void)
59−optimize = Opaleye.removeEmpty . Rel8.optimize . Opaleye.optimize
60−
61−
62−selectFrom :: Selects names exprs
63− => names -> exprs -> Opaleye.PrimQuery' Void -> Opaleye.Select
64−selectFrom (toColumns -> names) (toColumns -> exprs) query =
65− Opaleye.SelectFrom $ Opaleye.newSelect
66− { Opaleye.attrs = Opaleye.SelectAttrs attributes
67− , Opaleye.tables = Opaleye.oneTable select
68− }
69− where
70− select = Opaleye.foldPrimQuery Opaleye.sqlQueryGenerator query
71− attributes = getConst $ htabulateA $ \field -> case hfield names field of
72− Col (Name name) -> case hfield exprs field of
73− DB (toPrimExpr -> expr) -> Const (pure (makeAttr name expr))
74− makeAttr label expr =
75− (Opaleye.sqlExpr expr, Just (Opaleye.SqlColumn label))
src/Rel8/Query/Set.hs+8−26
@@ -23,54 +23,36 @@ import Rel8.Table.Opaleye ( binaryspec )
23
23
24
24
25-- | Combine the results of two queries of the same type, collapsing
25-- | Combine the results of two queries of the same type, collapsing
26−-- duplicates. @union a b@ is the same as the SQL statement @x UNION b@.
26+-- duplicates. @union a b@ is the same as the SQL statement @a UNION b@.
27−--
28−-- >>> select c $ values [lit True, lit True, lit False] `union` values [lit True]
29−-- [False,True]
30union :: EqTable a => Query a -> Query a -> Query a
27union :: EqTable a => Query a -> Query a -> Query a
31union = zipOpaleyeWith (Opaleye.unionExplicit binaryspec)
28union = zipOpaleyeWith (Opaleye.unionExplicit binaryspec)
32
29
33
30
34-- | Combine the results of two queries of the same type, retaining duplicates.
31-- | Combine the results of two queries of the same type, retaining duplicates.
35−-- @unionAll a b@ is the same as the SQL statement @x UNION ALL b@.
32+-- @unionAll a b@ is the same as the SQL statement @a UNION ALL b@.
36−--
37−-- >>> select c $ values [lit True, lit True, lit False] `unionAll` values [lit True]
38−-- [True,True,False,True]
39unionAll :: Table Expr a => Query a -> Query a -> Query a
33unionAll :: Table Expr a => Query a -> Query a -> Query a
40unionAll = zipOpaleyeWith (Opaleye.unionAllExplicit binaryspec)
34unionAll = zipOpaleyeWith (Opaleye.unionAllExplicit binaryspec)
41
35
42
36
43-- | Find the intersection of two queries, collapsing duplicates. @intersect a
37-- | Find the intersection of two queries, collapsing duplicates. @intersect a
44−-- b@ is the same as the SQL statement @x INTERSECT b@.
38+-- b@ is the same as the SQL statement @a INTERSECT b@.
45−--
46−-- >>> select c $ values [lit True, lit True, lit False] `intersect` values [lit True]
47−-- [True]
48intersect :: EqTable a => Query a -> Query a -> Query a
39intersect :: EqTable a => Query a -> Query a -> Query a
49intersect = zipOpaleyeWith (Opaleye.intersectExplicit binaryspec)
40intersect = zipOpaleyeWith (Opaleye.intersectExplicit binaryspec)
50
41
51
42
52-- | Find the intersection of two queries, retaining duplicates. @intersectAll
43-- | Find the intersection of two queries, retaining duplicates. @intersectAll
53−-- a b@ is the same as the SQL statement @x INTERSECT ALL b@.
44+-- a b@ is the same as the SQL statement @a INTERSECT ALL b@.
54−--
55−-- >>> select c $ values [lit True, lit True, lit False] `intersectAll` values [lit True, lit True]
56−-- [True,True]
57−intersectAll :: Table Expr a => Query a -> Query a -> Query a
45+intersectAll :: EqTable a => Query a -> Query a -> Query a
58intersectAll = zipOpaleyeWith (Opaleye.intersectAllExplicit binaryspec)
46intersectAll = zipOpaleyeWith (Opaleye.intersectAllExplicit binaryspec)
59
47
60
48
61-- | Find the difference of two queries, collapsing duplicates @except a b@ is
49-- | Find the difference of two queries, collapsing duplicates @except a b@ is
62−-- the same as the SQL statement @x INTERSECT b@.
50+-- the same as the SQL statement @a EXCEPT b@.
63−--
64−-- >>> select c $ values [lit True, lit False, lit False] `except` values [lit True]
65−-- [False]
66except :: EqTable a => Query a -> Query a -> Query a
51except :: EqTable a => Query a -> Query a -> Query a
67except = zipOpaleyeWith (Opaleye.exceptExplicit binaryspec)
52except = zipOpaleyeWith (Opaleye.exceptExplicit binaryspec)
68
53
69
54
70-- | Find the difference of two queries, retaining duplicates. @exceptAll a b@
55-- | Find the difference of two queries, retaining duplicates. @exceptAll a b@
71−-- is the same as the SQL statement @x EXCEPT ALL b@.
56+-- is the same as the SQL statement @a EXCEPT ALL b@.
72−--
73−-- >>> select c $ values [lit True, lit False, lit False] `exceptAll` values [lit True]
74−-- [False,False]
75−exceptAll :: Table Expr a => Query a -> Query a -> Query a
57+exceptAll :: EqTable a => Query a -> Query a -> Query a
76exceptAll = zipOpaleyeWith (Opaleye.exceptAllExplicit binaryspec)
58exceptAll = zipOpaleyeWith (Opaleye.exceptAllExplicit binaryspec)
src/Rel8/Query/These.hs+62−53
@@ -1,4 +1,5 @@
1{-# language FlexibleContexts #-}
1{-# language FlexibleContexts #-}
2+{-# language GADTs #-}
2
3
3module Rel8.Query.These
4module Rel8.Query.These
4 ( alignBy
5 ( alignBy
@@ -7,100 +8,116 @@ module Rel8.Query.These
7 , keepThisTable, loseThisTable
8 , keepThisTable, loseThisTable
8 , keepThatTable, loseThatTable
9 , keepThatTable, loseThatTable
9 , keepThoseTable, loseThoseTable
10 , keepThoseTable, loseThoseTable
10− , bindTheseTable
11 , bitraverseTheseTable
11 , bitraverseTheseTable
12 )
12 )
13where
13where
14
14
15-- base
15-- base
16−import Data.Bifunctor ( bimap )
17import Prelude
16import Prelude
18
17
18+-- comonad
19+import Control.Comonad ( extract )
20+
19-- opaleye
21-- opaleye
20−import qualified Opaleye.Internal.Join as Opaleye
22+import qualified Opaleye.Internal.PackMap as Opaleye
21import qualified Opaleye.Internal.PrimQuery as Opaleye
23import qualified Opaleye.Internal.PrimQuery as Opaleye
24+import qualified Opaleye.Internal.QueryArr as Opaleye
25+import qualified Opaleye.Internal.Tag as Opaleye
22
26
23-- rel8
27-- rel8
24import Rel8.Expr ( Expr )
28import Rel8.Expr ( Expr )
25−import Rel8.Expr.Bool ( (&&.), boolExpr, not_ )
29+import Rel8.Expr.Bool ( boolExpr, not_ )
26−import Rel8.Expr.Opaleye ( toColumn, toPrimExpr )
30+import Rel8.Expr.Eq ( (==.) )
31+import Rel8.Expr.Opaleye ( toPrimExpr, traversePrimExpr )
27import Rel8.Expr.Serialize ( litExpr )
32import Rel8.Expr.Serialize ( litExpr )
28import Rel8.Query ( Query )
33import Rel8.Query ( Query )
29import Rel8.Query.Filter ( where_ )
34import Rel8.Query.Filter ( where_ )
30−import Rel8.Query.Maybe ( traverseMaybeTable )
35+import Rel8.Query.Maybe ( optional )
31import Rel8.Query.Opaleye ( zipOpaleyeWith )
36import Rel8.Query.Opaleye ( zipOpaleyeWith )
32−import Rel8.Table ( Table )
33import Rel8.Table.Either ( EitherTable( EitherTable ) )
37import Rel8.Table.Either ( EitherTable( EitherTable ) )
34import Rel8.Table.Maybe ( MaybeTable( MaybeTable ), isJustTable )
38import Rel8.Table.Maybe ( MaybeTable( MaybeTable ), isJustTable )
35−import Rel8.Table.Opaleye ( unpackspec )
36import Rel8.Table.These
39import Rel8.Table.These
37− ( TheseTable( TheseTable )
40+ ( TheseTable( TheseTable, here, there )
41+ , hasHereTable, hasThereTable
38 , isThisTable, isThatTable, isThoseTable
42 , isThisTable, isThatTable, isThoseTable
39 )
43 )
40import Rel8.Type.Tag ( EitherTag( IsLeft, IsRight ) )
44import Rel8.Type.Tag ( EitherTag( IsLeft, IsRight ) )
41
45
42
46
43-- | Corresponds to a @FULL OUTER JOIN@ between two queries.
47-- | Corresponds to a @FULL OUTER JOIN@ between two queries.
44−alignBy :: (Table Expr a, Table Expr b)
48+alignBy :: ()
45 => (a -> b -> Expr Bool)
49 => (a -> b -> Expr Bool)
46− -> Query a -> Query b -> Query (TheseTable a b)
50+ -> Query a -> Query b -> Query (TheseTable Expr a b)
47−alignBy condition as bs =
51+alignBy condition = zipOpaleyeWith $ \left right -> Opaleye.stateQueryArr $ \_ t -> case t of
48− uncurry TheseTable <$> zipOpaleyeWith fullOuterJoin as bs
52+ tag -> (tab, join', tag''')
49− where
53+ where
50− fullOuterJoin a b =
54+ (ma, left', tag') = Opaleye.runStateQueryArr (pure <$> left) () tag
51− Opaleye.joinExplicit unpackspec unpackspec pure pure full a b on
55+ (mb, right', tag'') = Opaleye.runStateQueryArr (pure <$> right) () tag'
52− where
56+ MaybeTable hasHere a = ma
57+ MaybeTable hasThere b = mb
58+ (hasHere', lbindings) = Opaleye.run $ do
59+ traversePrimExpr (Opaleye.extractAttr "hasHere" tag'') hasHere
60+ (hasThere', rbindings) = Opaleye.run $ do
61+ traversePrimExpr (Opaleye.extractAttr "hasThere" tag'') hasThere
62+ tag''' = Opaleye.next tag''
53− full = Opaleye.FullJoin
63+ join = Opaleye.Join Opaleye.FullJoin on left'' right''
54− on = toColumn . toPrimExpr . uncurry condition
64+ where
55−
65+ on = toPrimExpr $ condition (extract a) (extract b)
56−
66+ left'' = (Opaleye.NonLateral, Opaleye.toPrimQuery (left' <> Opaleye.aRebind lbindings))
67+ right'' = (Opaleye.NonLateral, Opaleye.toPrimQuery (right' <> Opaleye.aRebind rbindings))
68+ ma' = MaybeTable hasHere' a
69+ mb' = MaybeTable hasThere' b
70+ tab = TheseTable {here = ma', there = mb'}
71+ join' = Opaleye.aProduct join
72+
73+
57−keepHereTable :: TheseTable a b -> Query (a, MaybeTable b)
74+keepHereTable :: TheseTable Expr a b -> Query (a, MaybeTable Expr b)
58keepHereTable = loseThatTable
75keepHereTable = loseThatTable
59
76
60
77
61−loseHereTable :: TheseTable a b -> Query b
78+loseHereTable :: TheseTable Expr a b -> Query b
62loseHereTable = keepThatTable
79loseHereTable = keepThatTable
63
80
64
81
65−keepThereTable :: TheseTable a b -> Query (MaybeTable a, b)
82+keepThereTable :: TheseTable Expr a b -> Query (MaybeTable Expr a, b)
66keepThereTable = loseThisTable
83keepThereTable = loseThisTable
67
84
68
85
69−loseThereTable :: TheseTable a b -> Query a
86+loseThereTable :: TheseTable Expr a b -> Query a
70loseThereTable = keepThisTable
87loseThereTable = keepThisTable
71
88
72
89
73−keepThisTable :: TheseTable a b -> Query a
90+keepThisTable :: TheseTable Expr a b -> Query a
74keepThisTable t@(TheseTable (MaybeTable _ a) _) = do
91keepThisTable t@(TheseTable (MaybeTable _ a) _) = do
75 where_ $ isThisTable t
92 where_ $ isThisTable t
76− pure a
93+ pure (extract a)
77
94
78
95
79−loseThisTable :: TheseTable a b -> Query (MaybeTable a, b)
96+loseThisTable :: TheseTable Expr a b -> Query (MaybeTable Expr a, b)
80loseThisTable t@(TheseTable ma (MaybeTable _ b)) = do
97loseThisTable t@(TheseTable ma (MaybeTable _ b)) = do
81 where_ $ not_ $ isThisTable t
98 where_ $ not_ $ isThisTable t
82− pure (ma, b)
99+ pure (ma, extract b)
83
100
84
101
85−keepThatTable :: TheseTable a b -> Query b
102+keepThatTable :: TheseTable Expr a b -> Query b
86keepThatTable t@(TheseTable _ (MaybeTable _ b)) = do
103keepThatTable t@(TheseTable _ (MaybeTable _ b)) = do
87 where_ $ isThatTable t
104 where_ $ isThatTable t
88− pure b
105+ pure (extract b)
89
106
90
107
91−loseThatTable :: TheseTable a b -> Query (a, MaybeTable b)
108+loseThatTable :: TheseTable Expr a b -> Query (a, MaybeTable Expr b)
92loseThatTable t@(TheseTable (MaybeTable _ a) mb) = do
109loseThatTable t@(TheseTable (MaybeTable _ a) mb) = do
93 where_ $ not_ $ isThatTable t
110 where_ $ not_ $ isThatTable t
94− pure (a, mb)
111+ pure (extract a, mb)
95
112
96
113
97−keepThoseTable :: TheseTable a b -> Query (a, b)
114+keepThoseTable :: TheseTable Expr a b -> Query (a, b)
98keepThoseTable t@(TheseTable (MaybeTable _ a) (MaybeTable _ b)) = do
115keepThoseTable t@(TheseTable (MaybeTable _ a) (MaybeTable _ b)) = do
99 where_ $ isThoseTable t
116 where_ $ isThoseTable t
100− pure (a, b)
117+ pure (extract a, extract b)
101
118
102
119
103−loseThoseTable :: TheseTable a b -> Query (EitherTable a b)
120+loseThoseTable :: TheseTable Expr a b -> Query (EitherTable Expr a b)
104loseThoseTable t@(TheseTable (MaybeTable _ a) (MaybeTable _ b)) = do
121loseThoseTable t@(TheseTable (MaybeTable _ a) (MaybeTable _ b)) = do
105 where_ $ not_ $ isThoseTable t
122 where_ $ not_ $ isThoseTable t
106 pure $ EitherTable tag a b
123 pure $ EitherTable tag a b
@@ -108,22 +125,14 @@ loseThoseTable t@(TheseTable (MaybeTable _ a) (MaybeTable _ b)) = do
108 tag = boolExpr (litExpr IsLeft) (litExpr IsRight) (isThatTable t)
125 tag = boolExpr (litExpr IsLeft) (litExpr IsRight) (isThatTable t)
109
126
110
127
111−bindTheseTable :: (Table Expr a, Semigroup a, Monad m)
112− => (i -> m (TheseTable a b)) -> TheseTable a i -> m (TheseTable a b)
113−bindTheseTable query (TheseTable here (MaybeTable input i)) = do
114− TheseTable here' (MaybeTable output b) <- query i
115− pure $ TheseTable (here <> here') (MaybeTable (input <> output) b)
116−
117−
118−bitraverseTheseTable :: (Table Expr c, Table Expr d)
128+bitraverseTheseTable :: ()
119 => (a -> Query c)
129 => (a -> Query c)
120 -> (b -> Query d)
130 -> (b -> Query d)
121− -> TheseTable a b
131+ -> TheseTable Expr a b
122− -> Query (TheseTable c d)
132+ -> Query (TheseTable Expr c d)
123−bitraverseTheseTable f g (TheseTable here there) =
133+bitraverseTheseTable f g t = do
124− bimap fromJustTable fromJustTable <$>
134+ mc <- optional (f . fst =<< keepHereTable t)
125− alignBy (\l r -> isJustTable l &&. isJustTable r)
135+ md <- optional (g . snd =<< keepThereTable t)
126− (traverseMaybeTable f here)
136+ where_ $ isJustTable mc ==. hasHereTable t
127− (traverseMaybeTable g there)
137+ where_ $ isJustTable md ==. hasThereTable t
128− where
138+ pure $ TheseTable mc md
129− fromJustTable (MaybeTable _ a) = a
src/Rel8/Query/Values.hs+1−7
@@ -21,13 +21,7 @@ import Rel8.Table.Opaleye ( valuesspec )
21
21
22
22
23-- | Construct a query that returns the given input list of rows. This is like
23-- | Construct a query that returns the given input list of rows. This is like
24−-- folding a list of 'return' statements under 'union', but uses the SQL
24+-- folding a list of 'return' statements under 'Rel8.union', but uses the SQL
25-- @VALUES@ expression for efficiency.
25-- @VALUES@ expression for efficiency.
26−--
27−-- Typically @values@ will be used with 'lit':
28−--
29−-- >>> mapM_ Data.Text.IO.putStrLn =<< select c (values [ lit "Hello", lit "World!" ])
30−-- Hello
31−-- World!
32values :: (Table Expr a, Foldable f) => f a -> Query a
26values :: (Table Expr a, Foldable f) => f a -> Query a
33values = fromOpaleye . Opaleye.valuesExplicit valuesspec . toList
27values = fromOpaleye . Opaleye.valuesExplicit valuesspec . toList
src/Rel8/Query/Window.hsnew file+26
@@ -0,0 +1,26 @@
1+module Rel8.Query.Window
2+ ( window
3+ )
4+where
5+
6+-- base
7+import Prelude ()
8+
9+-- opaleye
10+import qualified Opaleye.Window as Opaleye
11+
12+-- rel8
13+import Rel8.Query ( Query )
14+import Rel8.Query.Opaleye ( mapOpaleye )
15+import Rel8.Window ( Window( Window ) )
16+
17+
18+-- | 'window' runs a query composed of expressions containing
19+-- [window functions](https://www.postgresql.org/docs/current/tutorial-window.html).
20+-- 'window' is similar to 'Rel8.aggregate', with the main difference being
21+-- that in a window query, each input row corresponds to one output row,
22+-- whereas aggregation queries fold the entire input query down into a single
23+-- row. To put this into a Haskell context, 'Rel8.aggregate' is to 'foldl' as
24+-- 'window' is to 'scanl'.
25+window :: Window a b -> Query a -> Query b
26+window (Window a) = mapOpaleye (Opaleye.runWindows a)
src/Rel8/Schema/Column.hsdeleted−142
@@ -1,142 +0,0 @@
1−{-# language DataKinds #-}
2−{-# language TypeFamilies #-}
3−{-# language StandaloneKindSignatures #-}
4−
5−module Rel8.Schema.Column
6− ( Column, Default, Label
7− , HEither
8− , HList
9− , HMaybe
10− , HNonEmpty
11− , HThese
12− )
13−where
14−
15−-- base
16−import Data.Functor.Identity ( Identity )
17−import Data.Kind ( Type )
18−import Data.List.NonEmpty ( NonEmpty )
19−import GHC.TypeLits ( Symbol )
20−import Prelude
21−
22−-- rel8
23−import Rel8.Kind.Labels ( Labels )
24−import Rel8.Kind.Necessity ( Necessity( Required, Optional ) )
25−import Rel8.Schema.Context ( IsSpecialContext )
26−import Rel8.Schema.Field ( Field )
27−import qualified Rel8.Schema.Kind as K
28−import Rel8.Schema.Nullability ( Unnullify )
29−import Rel8.Schema.Structure
30− ( Structure
31− , Shape( Either, List, Maybe, NonEmpty, These )
32− , Shape1
33− , Shape2
34− )
35−import Rel8.Table.Either ( EitherTable )
36−import Rel8.Table.List ( ListTable )
37−import Rel8.Table.Maybe ( MaybeTable )
38−import Rel8.Table.NonEmpty ( NonEmptyTable )
39−import Rel8.Table.These ( TheseTable )
40−
41−-- these
42−import Data.These ( These )
43−
44−
45−type Label :: Symbol -> Type -> Type
46−data Label label a
47−
48−
49−type Default :: Type -> Type
50−data Default a
51−
52−
53−type GetLabel :: Type -> Labels
54−type family GetLabel a where
55− GetLabel (Label label _) = '[label]
56− GetLabel _ = '[]
57−
58−
59−type UnwrapLabel :: Type -> Type
60−type family UnwrapLabel a where
61− UnwrapLabel (Label _ a) = a
62− UnwrapLabel a = a
63−
64−
65−type GetNecessity :: Type -> Necessity
66−type family GetNecessity a where
67− GetNecessity (Default _) = 'Optional
68− GetNecessity _ = 'Required
69−
70−
71−type UnwrapDefault :: Type -> Type
72−type family UnwrapDefault a where
73− UnwrapDefault (Default a) = a
74− UnwrapDefault a = a
75−
76−
77−type Column :: K.Context -> Type -> Type
78−type Column context a =
79− Field context (GetLabel a)
80− (GetNecessity (UnwrapLabel a))
81− (Unnullify (UnwrapDefault (UnwrapLabel a)))
82− (UnwrapDefault (UnwrapLabel a))
83−
84−
85−type IHEither :: Bool -> K.Context -> Type -> Type -> Type
86−type family IHEither isSpecialContext context where
87− IHEither 'False _ = EitherTable
88− IHEither 'True Identity = Either
89− IHEither 'True Structure = Shape2 'Either
90− IHEither 'True _ = EitherTable
91−
92−
93−type IHList :: Bool -> K.Context -> Type -> Type
94−type family IHList isSpecialContext context where
95− IHList 'False _ = ListTable
96− IHList 'True Identity = []
97− IHList 'True Structure = Shape1 'List
98− IHList 'True _ = ListTable
99−
100−
101−type IHMaybe :: Bool -> K.Context -> Type -> Type
102−type family IHMaybe isSpecialContext context where
103− IHMaybe 'False _ = MaybeTable
104− IHMaybe 'True Identity = Maybe
105− IHMaybe 'True Structure = Shape1 'Maybe
106− IHMaybe 'True _ = MaybeTable
107−
108−
109−type IHNonEmpty :: Bool -> K.Context -> Type -> Type
110−type family IHNonEmpty isSpecialContext context where
111− IHNonEmpty 'False _ = NonEmptyTable
112− IHNonEmpty 'True Identity = NonEmpty
113− IHNonEmpty 'True Structure = Shape1 'NonEmpty
114− IHNonEmpty 'True _ = NonEmptyTable
115−
116−
117−type IHThese :: Bool -> K.Context -> Type -> Type -> Type
118−type family IHThese isSpecialContext context where
119− IHThese 'False _ = TheseTable
120− IHThese 'True Identity = These
121− IHThese 'True Structure = Shape2 'These
122− IHThese 'True _ = TheseTable
123−
124−
125−type HEither :: K.Context -> Type -> Type -> Type
126−type HEither context = IHEither (IsSpecialContext context) context
127−
128−
129−type HList :: K.Context -> Type -> Type
130−type HList context = IHList (IsSpecialContext context) context
131−
132−
133−type HMaybe :: K.Context -> Type -> Type
134−type HMaybe context = IHMaybe (IsSpecialContext context) context
135−
136−
137−type HNonEmpty :: K.Context -> Type -> Type
138−type HNonEmpty context = IHNonEmpty (IsSpecialContext context) context
139−
140−
141−type HThese :: K.Context -> Type -> Type -> Type
142−type HThese context = IHThese (IsSpecialContext context) context
src/Rel8/Schema/Context.hsdeleted−100
@@ -1,100 +0,0 @@
1−{-# language DataKinds #-}
2−{-# language DerivingStrategies #-}
3−{-# language FlexibleContexts #-}
4−{-# language FlexibleInstances #-}
5−{-# language GADTs #-}
6−{-# language GeneralizedNewtypeDeriving #-}
7−{-# language MultiParamTypeClasses #-}
8−{-# language ScopedTypeVariables #-}
9−{-# language StandaloneDeriving #-}
10−{-# language StandaloneKindSignatures #-}
11−{-# language TypeApplications #-}
12−{-# language TypeFamilies #-}
13−{-# language UndecidableInstances #-}
14−
15−module Rel8.Schema.Context
16− ( Col'( .. )
17− , Interpretation, Col
18− , Insertion(..)
19− , Name(..)
20− , IsSpecialContext
21− )
22−where
23−
24−-- base
25−import Data.Functor.Identity ( Identity )
26−import Data.Kind ( Constraint )
27−import Data.String ( IsString )
28−import Prelude
29−
30−-- rel8
31−import Rel8.Aggregate ( Aggregate )
32−import Rel8.Expr ( Expr )
33−import Rel8.Kind.Necessity ( Necessity( Optional, Required ) )
34−import qualified Rel8.Schema.Kind as K
35−import Rel8.Schema.Spec ( Spec( Spec ) )
36−import Rel8.Schema.Structure ( Structure )
37−
38−
39−type Interpretation' :: Bool -> K.Context -> Constraint
40−class IsSpecialContext f ~ isSpecial => Interpretation' isSpecial f where
41− data Col' isSpecial f :: K.HContext
42−
43−
44−instance Interpretation' 'True Aggregate where
45− data Col' 'True Aggregate _spec where
46− Aggregation :: ()
47− => Aggregate (Expr a)
48− -> Col' 'True Aggregate ('Spec labels necessity db a)
49−
50−
51−instance Interpretation' 'True Expr where
52− data Col' 'True Expr _spec where
53− DB :: ()
54− => { unDB :: Expr a }
55− -> Col' 'True Expr ('Spec labels necessity db a)
56−
57−
58−instance Interpretation' 'True Identity where
59− data Col' 'True Identity _spec where
60− Result :: a -> Col' 'True Identity ('Spec labels necessity db a)
61−
62−
63−instance Interpretation' 'True Insertion where
64− data Col' 'True Insertion _spec where
65− RequiredInsert :: Expr a -> Col' 'True Insertion ('Spec labels 'Required db a)
66− OptionalInsert :: Maybe (Expr a) -> Col' 'True Insertion ('Spec labels 'Optional db a)
67−
68−
69−instance IsSpecialContext f ~ 'False => Interpretation' 'False f where
70− data Col' 'False f _spec where
71− Col :: f a -> Col' 'False f ('Spec labels necessity db a)
72−
73−
74−type Interpretation :: K.Context -> Constraint
75−class Interpretation' (IsSpecialContext context) context => Interpretation context
76−instance Interpretation' (IsSpecialContext context) context => Interpretation context
77−
78−
79−type Col :: K.Context -> K.HContext
80−type Col context = Col' (IsSpecialContext context) context
81−
82−
83−type Insertion :: K.Context
84−newtype Insertion a = Insertion (Expr a)
85−
86−
87−type Name :: K.Context
88−newtype Name a = Name String
89− deriving stock Show
90− deriving newtype (IsString, Monoid, Semigroup)
91−
92−
93−type IsSpecialContext :: K.Context -> Bool
94−type family IsSpecialContext context where
95− IsSpecialContext Aggregate = 'True
96− IsSpecialContext Expr = 'True
97− IsSpecialContext Insertion = 'True
98− IsSpecialContext Identity = 'True
99− IsSpecialContext Structure = 'True
100− IsSpecialContext _ = 'False
src/Rel8/Schema/Context/Identity.hsdeleted−198
@@ -1,198 +0,0 @@
1−{-# language DataKinds #-}
2−{-# language DisambiguateRecordFields #-}
3−{-# language NamedFieldPuns #-}
4−{-# language TypeFamilies #-}
5−
6−module Rel8.Schema.Context.Identity
7− ( fromHEitherTable, toHEitherTable
8− , fromHListTable, toHListTable
9− , fromHMaybeTable, toHMaybeTable
10− , fromHNonEmptyTable, toHNonEmptyTable
11− , fromHTheseTable, toHTheseTable
12− )
13−where
14−
15−-- base
16−import Data.Functor ( ($>) )
17−import Data.Functor.Identity ( Identity )
18−import Data.List.NonEmpty ( NonEmpty )
19−import Prelude hiding ( null )
20−
21−-- rel8
22−import Rel8.Schema.Context ( Col, Col'( Result ) )
23−import Rel8.Schema.HTable ( HTable )
24−import Rel8.Schema.HTable.Either ( HEitherTable(..) )
25−import Rel8.Schema.HTable.Identity ( HIdentity(..) )
26−import Rel8.Schema.HTable.Maybe ( HMaybeTable(..) )
27−import Rel8.Schema.HTable.List ( HListTable )
28−import Rel8.Schema.HTable.NonEmpty ( HNonEmptyTable )
29−import Rel8.Schema.HTable.Nullify ( hnulls, hnullify, hunnullify )
30−import Rel8.Schema.HTable.These ( HTheseTable(..) )
31−import Rel8.Schema.HTable.Vectorize ( hvectorize, hunvectorize )
32−import Rel8.Schema.Nullability
33− ( Nullability( Nullable, NonNullable )
34− )
35−import Rel8.Schema.Spec ( Spec( Spec ), SSpec(..) )
36−import Rel8.Type.Tag ( EitherTag( IsLeft, IsRight ), MaybeTag( IsJust ) )
37−
38−-- these
39−import Data.These ( These( This, That, These ) )
40−import Data.These.Combinators ( justHere, justThere )
41−
42−
43−toHEitherTable :: (HTable t, HTable u)
44− => Either (t (Col Identity)) (u (Col Identity))
45− -> HEitherTable t u (Col Identity)
46−toHEitherTable = either hleft hright
47− where
48− hleft table = HEitherTable
49− { htag = HIdentity (Result IsLeft)
50− , hleft = hnullify nullifier table
51− , hright = hnulls null
52− }
53− hright table = HEitherTable
54− { htag = HIdentity (Result IsRight)
55− , hleft = hnulls null
56− , hright = hnullify nullifier table
57− }
58−{-# INLINABLE toHEitherTable #-}
59−
60−
61−fromHEitherTable :: (HTable t, HTable u)
62− => HEitherTable t u (Col Identity)
63− -> Either (t (Col Identity)) (u (Col Identity))
64−fromHEitherTable HEitherTable {htag, hleft, hright} = case htag of
65− HIdentity (Result tag) -> case tag of
66− IsLeft -> maybe err Left $ hunnullify unnullifier hleft
67− IsRight -> maybe err Right $ hunnullify unnullifier hright
68− where
69− err = error "fromHEitherTable: mismatch between tag and data"
70−{-# INLINABLE fromHEitherTable #-}
71−
72−
73−toHListTable :: HTable t => [t (Col Identity)] -> HListTable t (Col Identity)
74−toHListTable = hvectorize vectorizer
75−{-# INLINABLE toHListTable #-}
76−
77−
78−fromHListTable :: HTable t => HListTable t (Col Identity) -> [t (Col Identity)]
79−fromHListTable = hunvectorize unvectorizer
80−{-# INLINABLE fromHListTable #-}
81−
82−
83−toHMaybeTable :: HTable t => Maybe (t (Col Identity)) -> HMaybeTable t (Col Identity)
84−toHMaybeTable = maybe hnothing hjust
85− where
86− hnothing = HMaybeTable
87− { htag = HIdentity (Result Nothing)
88− , hjust = hnulls null
89− }
90− hjust table = HMaybeTable
91− { htag = HIdentity (Result (Just IsJust))
92− , hjust = hnullify nullifier table
93− }
94−{-# INLINABLE toHMaybeTable #-}
95−
96−
97−fromHMaybeTable :: HTable t => HMaybeTable t (Col Identity) -> Maybe (t (Col Identity))
98−fromHMaybeTable HMaybeTable {htag, hjust} = case htag of
99− HIdentity (Result tag) -> tag $>
100− case hunnullify unnullifier hjust of
101− Nothing -> error "fromHMaybeTable: mismatch between tag and data"
102− Just just -> just
103−{-# INLINABLE fromHMaybeTable #-}
104−
105−
106−toHNonEmptyTable :: HTable t => NonEmpty (t (Col Identity)) -> HNonEmptyTable t (Col Identity)
107−toHNonEmptyTable = hvectorize vectorizer
108−{-# INLINABLE toHNonEmptyTable #-}
109−
110−
111−fromHNonEmptyTable :: HTable t => HNonEmptyTable t (Col Identity) -> NonEmpty (t (Col Identity))
112−fromHNonEmptyTable = hunvectorize unvectorizer
113−{-# INLINABLE fromHNonEmptyTable #-}
114−
115−
116−toHTheseTable :: (HTable t, HTable u)
117− => These (t (Col Identity)) (u (Col Identity))
118− -> HTheseTable t u (Col Identity)
119−toHTheseTable tables = HTheseTable
120− { hhereTag = relabel hhereTag
121− , hhere
122− , hthereTag = relabel hthereTag
123− , hthere
124− }
125− where
126− HMaybeTable
127− { htag = hhereTag
128− , hjust = hhere
129− } = toHMaybeTable (justHere tables)
130− HMaybeTable
131− { htag = hthereTag
132− , hjust = hthere
133− } = toHMaybeTable (justThere tables)
134−{-# INLINABLE toHTheseTable #-}
135−
136−
137−fromHTheseTable :: (HTable t, HTable u)
138− => HTheseTable t u (Col Identity)
139− -> These (t (Col Identity)) (u (Col Identity))
140−fromHTheseTable HTheseTable {hhereTag, hhere, hthereTag, hthere} =
141− case (fromHMaybeTable mhere, fromHMaybeTable mthere) of
142− (Just a, Nothing) -> This a
143− (Nothing, Just b) -> That b
144− (Just a, Just b) -> These a b
145− _ -> error "fromHTheseTable: mismatch between tags and data"
146− where
147− mhere = HMaybeTable
148− { htag = relabel hhereTag
149− , hjust = hhere
150− }
151− mthere = HMaybeTable
152− { htag = relabel hthereTag
153− , hjust = hthere
154− }
155−{-# INLINABLE fromHTheseTable #-}
156−
157−
158−null :: Col Identity ('Spec labels necessity db (Maybe db))
159−null = Result Nothing
160−
161−
162−nullifier :: ()
163− => SSpec ('Spec labels necessity db a)
164− -> Col Identity ('Spec labels necessity db a)
165− -> Col Identity ('Spec labels necessity db (Maybe db))
166−nullifier SSpec {nullability} (Result a) = Result $ case nullability of
167− Nullable -> a
168− NonNullable -> Just a
169−
170−
171−unnullifier :: ()
172− => SSpec ('Spec labels necessity db a)
173− -> Col Identity ('Spec labels necessity db (Maybe db))
174− -> Maybe (Col Identity ('Spec labels necessity db a))
175−unnullifier SSpec {nullability} (Result a) =
176− case nullability of
177− Nullable -> pure $ Result a
178− NonNullable -> Result <$> a
179−
180−
181−vectorizer :: Functor f
182− => SSpec ('Spec labels necessity db a)
183− -> f (Col Identity ('Spec labels necessity db a))
184− -> Col Identity ('Spec labels necessity (f a) (f a))
185−vectorizer _ = Result . fmap (\(Result a) -> a)
186−
187−
188−unvectorizer :: Functor f
189− => SSpec ('Spec labels necessity db a)
190− -> Col Identity ('Spec labels necessity (f a) (f a))
191− -> f (Col Identity ('Spec labels necessity db a))
192−unvectorizer _ (Result results) = Result <$> results
193−
194−
195−relabel :: ()
196− => HIdentity ('Spec labels necessity db a) (Col Identity)
197− -> HIdentity ('Spec relabels necessity db a) (Col Identity)
198−relabel (HIdentity (Result a)) = HIdentity (Result a)
src/Rel8/Schema/Context/Label.hsdeleted−89
@@ -1,89 +0,0 @@
1−{-# language DataKinds #-}
2−{-# language LambdaCase #-}
3−{-# language FlexibleInstances #-}
4−{-# language MultiParamTypeClasses #-}
5−{-# language StandaloneKindSignatures #-}
6−{-# language TypeFamilies #-}
7−{-# language TypeOperators #-}
8−
9−module Rel8.Schema.Context.Label
10− ( Labelable( labeler, unlabeler )
11− , HLabelable( hlabeler, hunlabeler )
12− )
13−where
14−
15−-- base
16−import Data.Functor.Identity ( Identity )
17−import Data.Kind ( Constraint )
18−import Prelude hiding ( null )
19−
20−-- rel8
21−import Rel8.Aggregate ( Aggregate )
22−import Rel8.Expr ( Expr )
23−import Rel8.Schema.Context
24− ( Interpretation, Col, Col'(..), IsSpecialContext
25− , Insertion
26− )
27−import qualified Rel8.Schema.Kind as K
28−import Rel8.Schema.Spec ( Spec( Spec ) )
29−
30−
31−type Labelable :: K.Context -> Constraint
32−class Interpretation context => Labelable context where
33− labeler :: ()
34− => Col context ('Spec labels necessity db a)
35− -> Col context ('Spec (label ': labels) necessity db a)
36−
37− unlabeler :: ()
38− => Col context ('Spec (label ': labels) necessity db a)
39− -> Col context ('Spec labels necessity db a)
40−
41−
42−instance Labelable Aggregate where
43− labeler (Aggregation aggregate) = Aggregation aggregate
44− unlabeler (Aggregation aggregate) = Aggregation aggregate
45−
46−
47−instance Labelable Expr where
48− labeler (DB a) = DB a
49− unlabeler (DB a) = DB a
50−
51−
52−instance Labelable Insertion where
53− labeler = \case
54− RequiredInsert a -> RequiredInsert a
55− OptionalInsert ma -> OptionalInsert ma
56−
57− unlabeler = \case
58− RequiredInsert a -> RequiredInsert a
59− OptionalInsert ma -> OptionalInsert ma
60−
61−
62−instance Labelable Identity where
63− labeler (Result a) = Result a
64− unlabeler (Result a) = Result a
65−
66−
67−instance {-# OVERLAPPABLE #-} IsSpecialContext context ~ 'False =>
68− Labelable context
69− where
70− labeler (Col a) = Col a
71− unlabeler (Col a) = Col a
72−
73−
74−type HLabelable :: K.HContext -> Constraint
75−class HLabelable context where
76− hlabeler :: ()
77− => context ('Spec labels necessity db a)
78− -> context ('Spec (label ': labels) necessity db a)
79−
80− hunlabeler :: ()
81− => context ('Spec (label ': labels) necessity db a)
82− -> context ('Spec labels necessity db a)
83−
84−
85−instance (Labelable context, x ~ IsSpecialContext context) =>
86− HLabelable (Col' x context)
87− where
88− hlabeler = labeler
89− hunlabeler = unlabeler
src/Rel8/Schema/Context/Nullify.hs+107−126
@@ -1,163 +1,144 @@
1{-# language DataKinds #-}
1{-# language DataKinds #-}
2−{-# language LambdaCase #-}
2+{-# language EmptyCase #-}
3{-# language FlexibleContexts #-}
3{-# language FlexibleContexts #-}
4−{-# language FlexibleInstances #-}
4+{-# language GADTs #-}
5−{-# language MultiParamTypeClasses #-}
5+{-# language LambdaCase #-}
6{-# language NamedFieldPuns #-}
6{-# language NamedFieldPuns #-}
7−{-# language ScopedTypeVariables #-}
8{-# language StandaloneKindSignatures #-}
7{-# language StandaloneKindSignatures #-}
9−{-# language TypeApplications #-}
10−{-# language TypeFamilies #-}
11
8
12module Rel8.Schema.Context.Nullify
9module Rel8.Schema.Context.Nullify
10+ ( Nullifiability(..), NonNullifiability(..), nullifiableOrNot, absurd
11+ , Nullifiable, nullifiability
13− ( Nullifiable( encodeTag, decodeTag, nullifier, unnullifier )
12+ , guarder, nullifier, unnullifier
14− , NullifiableEq
13+ , sguard, snullify
15 )
14 )
16where
15where
17
16
18-- base
17-- base
19−import Control.Applicative ( empty )
18+import Data.Bool ( bool )
20−import Data.Foldable ( fold )
19+import Data.Functor.Identity ( Identity( Identity ) )
21−import Data.Kind ( Constraint )
20+import Data.Kind ( Constraint, Type )
22−import qualified Data.List.NonEmpty as NonEmpty
23−import Data.Monoid ( First( First ), getFirst )
24import Prelude hiding ( null )
21import Prelude hiding ( null )
25
22
26-- opaleye
23-- opaleye
27import qualified Opaleye.Internal.HaskellDB.PrimQuery as Opaleye
24import qualified Opaleye.Internal.HaskellDB.PrimQuery as Opaleye
28
25
29-- rel8
26-- rel8
30−import Rel8.Aggregate ( Aggregate, foldInputs, mapInputs )
27+import Rel8.Aggregate ( Aggregate(..), zipOutputs )
31−import Rel8.Expr ( Expr( Expr ) )
28+import Rel8.Expr ( Expr )
32−import Rel8.Expr.Aggregate ( groupByExpr )
33import Rel8.Expr.Bool ( boolExpr )
29import Rel8.Expr.Bool ( boolExpr )
34import Rel8.Expr.Null ( nullify, unsafeUnnullify )
30import Rel8.Expr.Null ( nullify, unsafeUnnullify )
35−import Rel8.Expr.Opaleye ( fromPrimExpr, toPrimExpr )
31+import Rel8.Expr.Opaleye ( fromPrimExpr )
36−import Rel8.Kind.Labels ( KnownLabels, labelsSing, renderLabels )
37−import Rel8.Kind.Necessity ( Necessity( Required ) )
32+import Rel8.Kind.Context ( SContext(..) )
38−import Rel8.Schema.Context
33+import Rel8.Schema.Field ( Field )
39− ( Interpretation
40− , Col, Col'(..)
41− , Insertion
42− , Name( Name )
43− )
44import qualified Rel8.Schema.Kind as K
34import qualified Rel8.Schema.Kind as K
45−import Rel8.Schema.Nullability ( Nullability( Nullable, NonNullable ), Sql )
35+import Rel8.Schema.Name ( Name( Name ) )
46−import Rel8.Schema.Spec ( Spec( Spec ), SSpec(..) )
36+import Rel8.Schema.Null ( Nullify, Nullity( Null, NotNull ) )
47−import Rel8.Type.Eq ( DBEq )
37+import Rel8.Schema.Result ( Result )
48−import Rel8.Type.Monoid ( DBMonoid )
38+import Rel8.Schema.Spec ( Spec(..) )
49
39
50
40
51−type Nullifiable :: K.Context -> Constraint
41+type Nullifiability :: K.Context -> Type
52−class Interpretation context => Nullifiable context where
42+data Nullifiability context where
53− encodeTag :: (Sql DBEq a, KnownLabels labels)
43+ NAggregate :: Nullifiability Aggregate
54− => Expr a
44+ NExpr :: Nullifiability Expr
55− -> Col context ('Spec labels 'Required db a)
45+ NName :: Nullifiability Name
56−
57− decodeTag :: Sql DBMonoid a
58− => Col context ('Spec labels 'Required db a)
59− -> Expr a
60
46
61− nullifier :: ()
62− => Expr Bool
63− -> SSpec ('Spec labels necessity db a)
64− -> Col context ('Spec labels necessity db a)
65− -> Col context ('Spec labels necessity db (Maybe db))
66
47
67− unnullifier :: ()
48+type Nullifiable :: K.Context -> Constraint
68− => Expr Bool
49+class Nullifiable context where
69− -> SSpec ('Spec labels necessity db a)
50+ nullifiability :: Nullifiability context
70− -> Col context ('Spec labels necessity db (Maybe db))
71− -> Col context ('Spec labels necessity db a)
72
51
73
52
74instance Nullifiable Aggregate where
53instance Nullifiable Aggregate where
75− encodeTag = Aggregation . groupByExpr
54+ nullifiability = NAggregate
76− decodeTag (Aggregation aggregate) = fold $ undoGroupBy aggregate
77−
78− nullifier tag SSpec {nullability} (Aggregation aggregate) = Aggregation $
79− mapInputs (toPrimExpr . runTag nullability tag . fromPrimExpr) $
80− runTag nullability tag <$> aggregate
81−
82− unnullifier _ SSpec {nullability} (Aggregation aggregate) =
83− Aggregation $ unnull nullability <$> aggregate
84−
85− {-# INLINABLE encodeTag #-}
86− {-# INLINABLE decodeTag #-}
87− {-# INLINABLE nullifier #-}
88− {-# INLINABLE unnullifier #-}
89
55
90
56
91instance Nullifiable Expr where
57instance Nullifiable Expr where
92− encodeTag = DB
58+ nullifiability = NExpr
93− decodeTag (DB a) = a
94− nullifier tag SSpec {nullability} (DB a) = DB $ runTag nullability tag a
95− unnullifier _ SSpec {nullability} (DB a) = DB $ unnull nullability a
96−
97− {-# INLINABLE encodeTag #-}
98− {-# INLINABLE decodeTag #-}
99− {-# INLINABLE nullifier #-}
100− {-# INLINABLE unnullifier #-}
101−
102−
103−instance Nullifiable Insertion where
104− encodeTag = RequiredInsert
105− decodeTag (RequiredInsert a) = a
106−
107− nullifier tag SSpec {nullability} = \case
108− RequiredInsert a -> RequiredInsert $ runTag nullability tag a
109− OptionalInsert ma -> OptionalInsert $ runTag nullability tag <$> ma
110−
111− unnullifier _ SSpec {nullability} = \case
112− RequiredInsert a -> RequiredInsert $ unnull nullability a
113− OptionalInsert ma -> OptionalInsert $ unnull nullability <$> ma
114−
115− {-# INLINABLE encodeTag #-}
116− {-# INLINABLE decodeTag #-}
117− {-# INLINABLE nullifier #-}
118− {-# INLINABLE unnullifier #-}
119
59
120
60
121instance Nullifiable Name where
61instance Nullifiable Name where
122− encodeTag _ = nameFromLabel
62+ nullifiability = NName
123− decodeTag _ = mempty
63+
124− nullifier _ _ (Col (Name name)) = Col (Name name)
64+
125− unnullifier _ _ (Col (Name name)) = Col (Name name)
65+type NonNullifiability :: K.Context -> Type
126−
66+data NonNullifiability context where
127− {-# INLINABLE encodeTag #-}
67+ NField :: NonNullifiability (Field table)
128− {-# INLINABLE decodeTag #-}
68+ NResult :: NonNullifiability Result
129− {-# INLINABLE nullifier #-}
69+
130− {-# INLINABLE unnullifier #-}
70+
131−
71+nullifiableOrNot :: ()
132−
72+ => SContext context
133−type NullifiableEq :: K.Context -> K.Context -> Constraint
73+ -> Either (NonNullifiability context) (Nullifiability context)
134−class (a ~ b, Nullifiable b) => NullifiableEq a b
74+nullifiableOrNot = \case
135−instance (a ~ b, Nullifiable b) => NullifiableEq a b
75+ SAggregate -> Right NAggregate
136−
76+ SExpr -> Right NExpr
137−
77+ SField -> Left NField
138−runTag :: Nullability db a -> Expr Bool -> Expr a -> Expr (Maybe db)
78+ SName -> Right NName
139−runTag nullability tag a = case nullability of
79+ SResult -> Left NResult
140− Nullable -> boolExpr null a tag
80+
141− NonNullable -> boolExpr null (nullify a) tag
81+
82+absurd :: Nullifiability context -> NonNullifiability context -> a
83+absurd = \case
84+ NAggregate -> \case
85+ NExpr -> \case
86+ NName -> \case
87+
88+
89+guarder :: ()
90+ => SContext context
91+ -> context tag
92+ -> (tag -> Bool)
93+ -> (Expr tag -> Expr Bool)
94+ -> context (Maybe a)
95+ -> context (Maybe a)
96+guarder = \case
97+ SAggregate -> \tag _ isNonNull -> zipOutputs (sguard . isNonNull) tag
98+ SExpr -> \tag _ isNonNull -> sguard (isNonNull tag)
99+ SField -> \_ _ _ -> id
100+ SName -> \_ _ _ -> id
101+ SResult -> \(Identity tag) isNonNull _ (Identity a) ->
102+ Identity (bool Nothing a (isNonNull tag))
103+
104+
105+nullifier :: ()
106+ => Nullifiability context
107+ -> Spec a
108+ -> context a
109+ -> context (Nullify a)
110+nullifier = \case
111+ NAggregate -> \Spec {nullity} (Aggregate a) ->
112+ Aggregate $ snullify nullity <$> a
113+ NExpr -> \Spec {nullity} a -> snullify nullity a
114+ NName -> \_ (Name a) -> Name a
115+
116+
117+unnullifier :: ()
118+ => Nullifiability context
119+ -> Spec a
120+ -> context (Nullify a)
121+ -> context a
122+unnullifier = \case
123+ NAggregate -> \Spec {nullity} (Aggregate a) ->
124+ Aggregate $ sunnullify nullity <$> a
125+ NExpr -> \Spec {nullity} a -> sunnullify nullity a
126+ NName -> \_ (Name a) -> Name a
127+
128+
129+sguard :: Expr Bool -> Expr (Maybe a) -> Expr (Maybe a)
130+sguard condition a = boolExpr null a condition
142 where
131 where
143− null = Expr (Opaleye.ConstExpr Opaleye.NullLit)
132+ null = fromPrimExpr $ Opaleye.ConstExpr Opaleye.NullLit
144−
145
133
146−unnull :: Nullability db a -> Expr (Maybe db) -> Expr a
147−unnull nullability a = case nullability of
148− Nullable -> a
149− NonNullable -> unsafeUnnullify a
150
134
151−
135+snullify :: Nullity a -> Expr a -> Expr (Nullify a)
152−-- HACK
136+snullify nullity a = case nullity of
153−undoGroupBy :: Aggregate (Expr _a) -> Maybe (Expr a)
137+ Null -> a
154−undoGroupBy = getFirst . foldInputs go
138+ NotNull -> nullify a
155− where
156− go Nothing a = pure (Expr a)
157− go _ _ = First empty
158
139
159
140
160−nameFromLabel :: forall labels necessity db a.
141+sunnullify :: Nullity a -> Expr (Nullify a) -> Expr a
161− KnownLabels labels => Col Name ('Spec labels necessity db a)
142+sunnullify nullity a = case nullity of
162−nameFromLabel = case labelsSing @labels of
143+ Null -> a
163− labels -> Col (Name (NonEmpty.last (renderLabels labels)))
144+ NotNull -> unsafeUnnullify a
src/Rel8/Schema/Field.hs+37−27
@@ -1,40 +1,50 @@
1{-# language DataKinds #-}
1{-# language DataKinds #-}
2+{-# language FlexibleContexts #-}
3+{-# language MultiParamTypeClasses #-}
2{-# language StandaloneKindSignatures #-}
4{-# language StandaloneKindSignatures #-}
3{-# language TypeFamilies #-}
5{-# language TypeFamilies #-}
4−{-# language UndecidableInstances #-}
5
6
6module Rel8.Schema.Field
7module Rel8.Schema.Field
7− ( Field
8+ ( Field(..)
9+ , fields
8 )
10 )
9where
11where
10
12
11-- base
13-- base
12−import Data.Functor.Identity ( Identity )
14+import Data.Functor.Identity ( Identity( Identity ) )
13import Data.Kind ( Type )
15import Data.Kind ( Type )
14import Prelude
16import Prelude
15
17
16-- rel8
18-- rel8
17−import Rel8.Aggregate ( Aggregate )
19+import Rel8.Schema.HTable ( HField, htabulate )
18−import Rel8.Expr ( Expr )
20+import Rel8.Schema.HTable.Identity ( HIdentity( HIdentity ) )
19−import Rel8.Kind.Labels ( Labels )
20−import Rel8.Kind.Necessity ( Necessity( Required, Optional ) )
21−import Rel8.Schema.Context ( Insertion, IsSpecialContext )
22−import qualified Rel8.Schema.Kind as K
21+import Rel8.Schema.Kind as K
23−import Rel8.Schema.Spec ( Spec( Spec ) )
22+import Rel8.Schema.Null ( Sql )
24−import Rel8.Schema.Structure ( Structure, Shape( Column ), Shape1 )
23+import Rel8.Table
25−
24+ ( Table, Columns, Context, fromColumns, toColumns
26−
25+ , FromExprs, fromResult, toResult
27−type IField :: Bool -> K.Context -> Labels -> Necessity -> Type -> Type -> Type
26+ , Transpose
28−type family IField isSpecialContext labels context necessity db a where
27+ )
29− IField 'False context _labels _necessity _db a = context a
28+import Rel8.Table.Transpose ( Transposes )
30− IField 'True Identity _labels _necessity _db a = a
29+import Rel8.Type ( DBType )
31− IField 'True Expr _labels _necessity _db a = Expr a
30+
32− IField 'True Insertion _labels 'Required _db a = Expr a
31+
33− IField 'True Insertion _labels 'Optional _db a = Maybe (Expr a)
32+-- | A special context used in the construction of 'Rel8.Projection's.
34− IField 'True Aggregate _labels _necessity _db a = Aggregate (Expr a)
33+type Field :: Type -> K.Context
35− IField 'True Structure labels necessity db a = Shape1 'Column ('Spec labels necessity db a)
34+newtype Field table a = Field (HField (Columns table) a)
36−
35+
37−
36+
38−type Field :: K.Context -> Labels -> Necessity -> Type -> Type -> Type
37+instance Sql DBType a => Table (Field table) (Field table a) where
39−type Field context labels necessity db a =
38+ type Columns (Field table a) = HIdentity a
40− IField (IsSpecialContext context) context labels necessity db a
39+ type Context (Field table a) = Field table
40+ type FromExprs (Field table a) = a
41+ type Transpose to (Field table a) = to a
42+
43+ toColumns = HIdentity
44+ fromColumns (HIdentity a) = a
45+ toResult a = HIdentity (Identity a)
46+ fromResult (HIdentity (Identity a)) = a
47+
48+
49+fields :: Transposes context (Field table) table fields => fields
50+fields = fromColumns $ htabulate Field
src/Rel8/Schema/Generic.hsdeleted−1020
@@ -1,1020 +0,0 @@
1−{-# language AllowAmbiguousTypes #-}
2−{-# language DataKinds #-}
3−{-# language DisambiguateRecordFields #-}
4−{-# language DefaultSignatures #-}
5−{-# language FlexibleContexts #-}
6−{-# language FlexibleInstances #-}
7−{-# language GADTs #-}
8−{-# language MultiParamTypeClasses #-}
9−{-# language ScopedTypeVariables #-}
10−{-# language StandaloneKindSignatures #-}
11−{-# language TypeApplications #-}
12−{-# language TypeFamilies #-}
13−{-# language TypeOperators #-}
14−{-# language UndecidableInstances #-}
15−{-# language ViewPatterns #-}
16−
17−{-# options_ghc -fno-warn-orphans #-}
18−
19−module Rel8.Schema.Generic
20− ( Rel8able
21− )
22−where
23−
24−-- base
25−import Data.Bifunctor ( bimap )
26−import Data.Functor.Identity ( Identity )
27−import Data.Kind ( Constraint, Type )
28−import Data.List.NonEmpty ( NonEmpty )
29−import GHC.Generics
30− ( Generic, Rep, from, to
31− , (:*:)( (:*:) ), K1( K1 ), M1( M1 )
32− , D, C, S
33− , Meta( MetaSel )
34− )
35−import GHC.TypeLits ( Symbol )
36−import Prelude
37−
38−-- rel8
39−import Rel8.Aggregate ( Aggregate )
40−import Rel8.Expr ( Expr )
41−import Rel8.Kind.Necessity
42− ( SNecessity( SRequired, SOptional )
43− , KnownNecessity, necessitySing
44− )
45−import Rel8.Schema.Context
46−import Rel8.Schema.Context.Identity
47− ( fromHEitherTable, toHEitherTable
48− , fromHListTable, toHListTable
49− , fromHMaybeTable, toHMaybeTable
50− , fromHNonEmptyTable, toHNonEmptyTable
51− , fromHTheseTable, toHTheseTable
52− )
53−import Rel8.Schema.Context.Label
54− ( Labelable, labeler, unlabeler
55− , hlabeler, hunlabeler
56− )
57−import Rel8.Schema.Context.Nullify ( Nullifiable )
58−import Rel8.Schema.Field ( Field )
59−import Rel8.Schema.HTable ( HTable )
60−import Rel8.Schema.HTable.Either ( HEitherTable )
61−import Rel8.Schema.HTable.Identity ( HIdentity(..) )
62−import Rel8.Schema.HTable.Label ( HLabel, hlabel, hunlabel )
63−import Rel8.Schema.HTable.List ( HListTable )
64−import Rel8.Schema.HTable.Maybe ( HMaybeTable )
65−import Rel8.Schema.HTable.NonEmpty ( HNonEmptyTable )
66−import Rel8.Schema.HTable.Pair ( HPair(..) )
67−import Rel8.Schema.HTable.Quartet ( HQuartet(..) )
68−import Rel8.Schema.HTable.Quintet ( HQuintet(..) )
69−import Rel8.Schema.HTable.These ( HTheseTable )
70−import Rel8.Schema.HTable.Trio ( HTrio(..) )
71−import Rel8.Schema.HTable.Vectorize ( hrelabel )
72−import qualified Rel8.Schema.Kind as K
73−import Rel8.Schema.Spec ( Spec( Spec ), KTable )
74−import Rel8.Schema.Structure
75− ( IsStructure, Shape(..), Shape1, Shape2
76− , Structure
77− )
78−import Rel8.Table
79− ( Table, Columns, Context, fromColumns, toColumns
80− )
81−import Rel8.Table.Either ( EitherTable )
82−import Rel8.Table.Lifted
83− ( fromColumns1, toColumns1
84− , fromColumns2, toColumns2
85− )
86−import Rel8.Table.List ( ListTable )
87−import Rel8.Table.Maybe ( MaybeTable(..) )
88−import Rel8.Table.NonEmpty ( NonEmptyTable )
89−import Rel8.Table.These ( TheseTable )
90−
91−-- these
92−import Data.These ( These )
93−
94−
95−instance (Rel8able t, TableHelper (IsSpecialContext context) context) =>
96− Table context (t context)
97− where
98− type Columns (t context) = GRep t
99− type Context (t context) = context
100− fromColumns = gfromColumns
101− toColumns = gtoColumns
102−
103−
104−type TableHelper :: Bool -> K.Context -> Constraint
105−class IsSpecialContext context ~ isSpecialContext =>
106− TableHelper isSpecialContext context
107− where
108− gfromColumns :: Rel8able t => GRep t (Col context) -> t context
109− gtoColumns :: Rel8able t => t context -> GRep t (Col context)
110−
111−
112−instance TableHelper 'True Aggregate where
113− gfromColumns = fromAggregateColumns
114− gtoColumns = toAggregateColumns
115−
116−
117−instance TableHelper 'True Expr where
118− gfromColumns = fromExprColumns
119− gtoColumns = toExprColumns
120−
121−
122−instance TableHelper 'True Insertion where
123− gfromColumns = fromInsertionColumns
124− gtoColumns = toInsertionColumns
125−
126−
127−instance TableHelper 'True Identity where
128− gfromColumns = fromIdentityColumns
129− gtoColumns = toIdentityColumns
130−
131−
132−instance (IsSpecialContext context ~ 'False, Labelable context, Nullifiable context) =>
133− TableHelper 'False context
134− where
135− gfromColumns = fromUnspecialColumns
136− gtoColumns = toUnspecialColumns
137−
138−
139−type Rel8able :: KTable -> Constraint
140−class HTable (GRep t) => Rel8able t where
141− type GRep t :: K.HTable
142−
143− fromAggregateColumns :: GRep t (Col Aggregate) -> t Aggregate
144− toAggregateColumns :: t Aggregate -> GRep t (Col Aggregate)
145−
146− fromExprColumns :: GRep t (Col Expr) -> t Expr
147− toExprColumns :: t Expr -> GRep t (Col Expr)
148−
149− fromInsertionColumns :: GRep t (Col Insertion) -> t Insertion
150− toInsertionColumns :: t Insertion -> GRep t (Col Insertion)
151−
152− fromIdentityColumns :: GRep t (Col Identity) -> t Identity
153− toIdentityColumns :: t Identity -> GRep t (Col Identity)
154−
155− fromUnspecialColumns ::
156− ( IsSpecialContext context ~ 'False
157− , Labelable context, Nullifiable context
158− )
159− => GRep t (Col context) -> t context
160− toUnspecialColumns ::
161− ( IsSpecialContext context ~ 'False
162− , Labelable context, Nullifiable context
163− )
164− => t context -> GRep t (Col context)
165−
166− type GRep t = GColumns (Rep (t Structure))
167−
168− default fromAggregateColumns ::
169− ( Generic (t Aggregate)
170− , GColumns (Rep (t Structure)) ~ GRep t
171− , GRel8able Aggregate (Rep (t Structure)) (Rep (t Aggregate))
172− ) => GRep t (Col Aggregate) -> t Aggregate
173− fromAggregateColumns = to . fromGColumns @_ @(Rep (t Structure))
174−
175− default toAggregateColumns ::
176− ( Generic (t Aggregate)
177− , GColumns (Rep (t Structure)) ~ GRep t
178− , GRel8able Aggregate (Rep (t Structure)) (Rep (t Aggregate))
179− ) => t Aggregate -> GRep t (Col Aggregate)
180− toAggregateColumns = toGColumns @_ @(Rep (t Structure)) . from
181−
182− default fromExprColumns ::
183− ( Generic (t Expr)
184− , GColumns (Rep (t Structure)) ~ GRep t
185− , GRel8able Expr (Rep (t Structure)) (Rep (t Expr))
186− ) => GRep t (Col Expr) -> t Expr
187− fromExprColumns = to . fromGColumns @_ @(Rep (t Structure))
188−
189− default toExprColumns ::
190− ( Generic (t Expr)
191− , GColumns (Rep (t Structure)) ~ GRep t
192− , GRel8able Expr (Rep (t Structure)) (Rep (t Expr))
193− ) => t Expr -> GRep t (Col Expr)
194− toExprColumns = toGColumns @_ @(Rep (t Structure)) . from
195−
196− default fromInsertionColumns ::
197− ( Generic (t Insertion)
198− , GColumns (Rep (t Structure)) ~ GRep t
199− , GRel8able Insertion (Rep (t Structure)) (Rep (t Insertion))
200− ) => GRep t (Col Insertion) -> t Insertion
201− fromInsertionColumns = to . fromGColumns @_ @(Rep (t Structure))
202−
203− default toInsertionColumns ::
204− ( Generic (t Insertion)
205− , GColumns (Rep (t Structure)) ~ GRep t
206− , GRel8able Insertion (Rep (t Structure)) (Rep (t Insertion))
207− ) => t Insertion -> GRep t (Col Insertion)
208− toInsertionColumns = toGColumns @_ @(Rep (t Structure)) . from
209−
210− default fromIdentityColumns ::
211− ( Generic (t Identity)
212− , GColumns (Rep (t Structure)) ~ GRep t
213− , GRel8able Identity (Rep (t Structure)) (Rep (t Identity))
214− ) => GRep t (Col Identity) -> t Identity
215− fromIdentityColumns = to . fromGColumns @_ @(Rep (t Structure))
216−
217− default toIdentityColumns ::
218− ( Generic (t Identity)
219− , GColumns (Rep (t Structure)) ~ GRep t
220− , GRel8able Identity (Rep (t Structure)) (Rep (t Identity))
221− ) => t Identity -> GRep t (Col Identity)
222− toIdentityColumns = toGColumns @_ @(Rep (t Structure)) . from
223−
224− default fromUnspecialColumns ::
225− ( Generic (t context)
226− , GColumns (Rep (t Structure)) ~ GRep t
227− , GRel8able context (Rep (t Structure)) (Rep (t context))
228− ) => GRep t (Col context) -> t context
229− fromUnspecialColumns = to . fromGColumns @_ @(Rep (t Structure))
230−
231− default toUnspecialColumns ::
232− ( Generic (t context)
233− , GColumns (Rep (t Structure)) ~ GRep t
234− , GRel8able context (Rep (t Structure)) (Rep (t context))
235− ) => t context -> GRep t (Col context)
236− toUnspecialColumns = toGColumns @_ @(Rep (t Structure)) . from
237−
238−
239−type GColumns :: (Type -> Type) -> K.HTable
240−type family GColumns structure where
241− GColumns (M1 D _ structure) = GColumns structure
242− GColumns (M1 C _ structure) = GColumns structure
243− GColumns (a :*: b) = HPair (GColumns a) (GColumns b)
244− GColumns (M1 S ('MetaSel ('Just label) _ _ _) (K1 _ structure)) =
245− K1Columns label structure
246−
247−
248−type GRel8able :: K.Context -> (Type -> Type) -> (Type -> Type) -> Constraint
249−class GRel8able context structure rep where
250− fromGColumns :: GColumns structure (Col context) -> rep x
251− toGColumns :: rep x -> GColumns structure (Col context)
252−
253−
254−instance GRel8able context structure rep => GRel8able context (M1 D c structure) (M1 D c rep) where
255− fromGColumns = M1 . fromGColumns @context @structure @rep
256− toGColumns (M1 a) = toGColumns @context @structure @rep a
257−
258−
259−instance GRel8able context structure rep => GRel8able context (M1 C c structure) (M1 C c rep) where
260− fromGColumns = M1 . fromGColumns @context @structure @rep
261− toGColumns (M1 a) = toGColumns @context @structure @rep a
262−
263−
264−instance (GRel8able context structure1 rep1, GRel8able context structure2 rep2) =>
265− GRel8able context (structure1 :*: structure2) (rep1 :*: rep2)
266− where
267− fromGColumns (HPair a b) =
268− fromGColumns @context @structure1 @rep1 a :*:
269− fromGColumns @context @structure2 @rep2 b
270− toGColumns (a :*: b) =
271− HPair
272− (toGColumns @context @structure1 @rep1 a)
273− (toGColumns @context @structure2 @rep2 b)
274−
275−
276−instance
277− ( K1Table label isSpecialContext context isStructure structure a
278− , meta ~ 'MetaSel ('Just label) _su _ss _ds
279− , structureK1 ~ K1 i structure
280− , k1 ~ K1 i a
281− ) => GRel8able context (M1 S meta structureK1) (M1 S meta k1)
282− where
283− fromGColumns = M1 . K1 . fromK1Columns @label @_ @_ @_ @structure
284− toGColumns (M1 (K1 a)) = toK1Columns @label @_ @_ @_ @structure a
285−
286−
287−type K1Columns :: Symbol -> Type -> K.HTable
288−type family K1Columns label structure where
289− K1Columns label (Shape1 'Column ('Spec '[] necessity nullability blueprint)) =
290− HIdentity ('Spec '[label] necessity nullability blueprint)
291− K1Columns _label (Shape1 'Column ('Spec (label ': labels) necessity nullability blueprint)) =
292− HIdentity ('Spec (label ': labels) necessity nullability blueprint)
293− K1Columns label (Shape2 'Either a b) =
294− HLabel label (HEitherTable (K1Columns "Left" a) (K1Columns "Right" b))
295− K1Columns label (Shape1 'List a) = HListTable (K1Columns label a)
296− K1Columns label (Shape1 'Maybe a) = HLabel label (HMaybeTable (K1Columns "Just" a))
297− K1Columns label (Shape1 'NonEmpty a) = HNonEmptyTable (K1Columns label a)
298− K1Columns label (Shape2 'These a b) =
299− HLabel label (HTheseTable (K1Columns "Here" a) (K1Columns "There" b))
300− K1Columns label (a, b) =
301− HLabel label
302− (HPair
303− (K1Columns "fst" a)
304− (K1Columns "snd" b))
305− K1Columns label (a, b, c) =
306− HLabel label
307− (HTrio
308− (K1Columns "fst" a)
309− (K1Columns "snd" b)
310− (K1Columns "trd" c))
311− K1Columns label (a, b, c, d) =
312− HLabel label
313− (HQuartet
314− (K1Columns "fst" a)
315− (K1Columns "snd" b)
316− (K1Columns "trd" c)
317− (K1Columns "frt" d))
318− K1Columns label (a, b, c, d, e) =
319− HLabel label
320− (HQuintet
321− (K1Columns "fst" a)
322− (K1Columns "snd" b)
323− (K1Columns "trd" c)
324− (K1Columns "frt" d)
325− (K1Columns "fft" e))
326− K1Columns label a = HLabel label (Columns a)
327−
328−
329−type K1Table :: Symbol -> Bool -> K.Context -> Bool -> Type -> Type -> Constraint
330−class
331− ( isSpecialContext ~ IsSpecialContext context
332− , isStructure ~ IsStructure structure
333− ) => K1Table label isSpecialContext context isStructure structure a
334− where
335− fromK1Columns :: K1Columns label structure (Col context) -> a
336− toK1Columns :: a -> K1Columns label structure (Col context)
337−
338−
339−instance
340− ( x ~ Field Aggregate '[] necessity db a
341− ) => K1Table label 'True Aggregate 'True (Shape1 'Column ('Spec '[] necessity db a)) x
342− where
343− fromK1Columns (HIdentity (Aggregation a)) = a
344− toK1Columns = HIdentity . Aggregation
345− {-# INLINABLE fromK1Columns #-}
346− {-# INLINABLE toK1Columns #-}
347−
348−
349−instance
350− ( x ~ Field Aggregate (label ': labels) necessity db a
351− ) => K1Table _label 'True Aggregate 'True (Shape1 'Column ('Spec (label ': labels) necessity db a)) x
352− where
353− fromK1Columns (HIdentity (Aggregation a)) = a
354− toK1Columns = HIdentity . Aggregation
355− {-# INLINABLE fromK1Columns #-}
356− {-# INLINABLE toK1Columns #-}
357−
358−
359−instance
360− ( x ~ Field Expr '[] necessity db a
361− ) => K1Table label 'True Expr 'True (Shape1 'Column ('Spec '[] necessity db a)) x
362− where
363− fromK1Columns (HIdentity (DB a)) = a
364− toK1Columns = HIdentity . DB
365− {-# INLINABLE fromK1Columns #-}
366− {-# INLINABLE toK1Columns #-}
367−
368−
369−instance
370− ( x ~ Field Expr (label ': labels) necessity db a
371− ) => K1Table _label 'True Expr 'True (Shape1 'Column ('Spec (label ': labels) necessity db a)) x
372− where
373− fromK1Columns (HIdentity (DB a)) = a
374− toK1Columns = HIdentity . DB
375− {-# INLINABLE fromK1Columns #-}
376− {-# INLINABLE toK1Columns #-}
377−
378−
379−instance
380− ( x ~ Field Insertion '[] necessity db a
381− , KnownNecessity necessity
382− ) => K1Table label 'True Insertion 'True (Shape1 'Column ('Spec '[] necessity db a)) x
383− where
384− fromK1Columns (HIdentity insert) = case insert of
385− RequiredInsert a -> a
386− OptionalInsert ma -> ma
387− toK1Columns a = HIdentity $ case necessitySing @necessity of
388− SRequired -> RequiredInsert a
389− SOptional -> OptionalInsert a
390− {-# INLINABLE fromK1Columns #-}
391− {-# INLINABLE toK1Columns #-}
392−
393−
394−instance
395− ( x ~ Field Insertion (label ': labels) necessity db a
396− , KnownNecessity necessity
397− ) => K1Table _label 'True Insertion 'True (Shape1 'Column ('Spec (label ': labels) necessity db a)) x
398− where
399− fromK1Columns (HIdentity insert) = case insert of
400− RequiredInsert a -> a
401− OptionalInsert ma -> ma
402− toK1Columns a = HIdentity $ case necessitySing @necessity of
403− SRequired -> RequiredInsert a
404− SOptional -> OptionalInsert a
405− {-# INLINABLE fromK1Columns #-}
406− {-# INLINABLE toK1Columns #-}
407−
408−
409−instance
410− ( x ~ Field Identity '[] necessity db a
411− ) => K1Table label 'True Identity 'True (Shape1 'Column ('Spec '[] necessity db a)) x
412− where
413− fromK1Columns (HIdentity (Result a)) = a
414− toK1Columns = HIdentity . Result
415− {-# INLINABLE fromK1Columns #-}
416− {-# INLINABLE toK1Columns #-}
417−
418−
419−instance
420− ( x ~ Field Identity (label ': labels) necessity db a
421− ) => K1Table _label 'True Identity 'True (Shape1 'Column ('Spec (label ': labels) necessity db a)) x
422− where
423− fromK1Columns (HIdentity (Result a)) = a
424− toK1Columns = HIdentity . Result
425− {-# INLINABLE fromK1Columns #-}
426− {-# INLINABLE toK1Columns #-}
427−
428−
429−instance
430− ( IsSpecialContext context ~ 'False
431− , x ~ context a
432− ) => K1Table _label 'False context 'True (Shape1 'Column ('Spec (label ': labels) necessity db a)) x
433− where
434− fromK1Columns (HIdentity (Col a)) = a
435− toK1Columns = HIdentity . Col
436− {-# INLINABLE fromK1Columns #-}
437− {-# INLINABLE toK1Columns #-}
438−
439−
440−instance
441− ( IsSpecialContext context ~ 'False
442− , x ~ context a
443− , Labelable context
444− ) => K1Table label 'False context 'True (Shape1 'Column ('Spec '[] necessity db a)) x
445− where
446− fromK1Columns = (\(Col a) -> a) . unlabeler . unHIdentity
447− toK1Columns = HIdentity . labeler . Col
448− {-# INLINABLE fromK1Columns #-}
449− {-# INLINABLE toK1Columns #-}
450−
451−
452−instance
453− ( HTable (K1Columns "Left" structure1)
454− , HTable (K1Columns "Right" structure2)
455− , K1Table "Left" 'True Aggregate (IsStructure structure1) structure1 a
456− , K1Table "Right" 'True Aggregate (IsStructure structure2) structure2 b
457− , e ~ EitherTable a b
458− ) => K1Table label 'True Aggregate 'True (Shape2 'Either structure1 structure2) e
459− where
460− fromK1Columns =
461− fromColumns2
462− (fromK1Columns @"Left" @_ @_ @_ @structure1)
463− (fromK1Columns @"Right" @_ @_ @_ @structure2) .
464− hunlabel unlabeler
465− toK1Columns =
466− hlabel labeler .
467− toColumns2
468− (toK1Columns @"Left" @_ @_ @_ @structure1)
469− (toK1Columns @"Right" @_ @_ @_ @structure2)
470− {-# INLINABLE fromK1Columns #-}
471− {-# INLINABLE toK1Columns #-}
472−
473−
474−instance
475− ( HTable (K1Columns "Left" structure1)
476− , HTable (K1Columns "Right" structure2)
477− , K1Table "Left" 'True Expr (IsStructure structure1) structure1 a
478− , K1Table "Right" 'True Expr (IsStructure structure2) structure2 b
479− , e ~ EitherTable a b
480− ) => K1Table label 'True Expr 'True (Shape2 'Either structure1 structure2) e
481− where
482− fromK1Columns =
483− fromColumns2
484− (fromK1Columns @"Left" @_ @_ @_ @structure1)
485− (fromK1Columns @"Right" @_ @_ @_ @structure2) .
486− hunlabel unlabeler
487− toK1Columns =
488− hlabel labeler .
489− toColumns2
490− (toK1Columns @"Left" @_ @_ @_ @structure1)
491− (toK1Columns @"Right" @_ @_ @_ @structure2)
492− {-# INLINABLE fromK1Columns #-}
493− {-# INLINABLE toK1Columns #-}
494−
495−
496−instance
497− ( HTable (K1Columns "Left" structure1)
498− , HTable (K1Columns "Right" structure2)
499− , K1Table "Left" 'True Insertion (IsStructure structure1) structure1 a
500− , K1Table "Right" 'True Insertion (IsStructure structure2) structure2 b
501− , e ~ EitherTable a b
502− ) => K1Table label 'True Insertion 'True (Shape2 'Either structure1 structure2) e
503− where
504− fromK1Columns =
505− fromColumns2
506− (fromK1Columns @"Left" @_ @_ @_ @structure1)
507− (fromK1Columns @"Right" @_ @_ @_ @structure2) .
508− hunlabel unlabeler
509− toK1Columns =
510− hlabel labeler .
511− toColumns2
512− (toK1Columns @"Left" @_ @_ @_ @structure1)
513− (toK1Columns @"Right" @_ @_ @_ @structure2)
514− {-# INLINABLE fromK1Columns #-}
515− {-# INLINABLE toK1Columns #-}
516−
517−
518−instance
519− ( HTable (K1Columns "Left" structure1)
520− , HTable (K1Columns "Right" structure2)
521− , K1Table "Left" 'True Identity (IsStructure structure1) structure1 a
522− , K1Table "Right" 'True Identity (IsStructure structure2) structure2 b
523− , e ~ Either a b
524− ) => K1Table label 'True Identity 'True (Shape2 'Either structure1 structure2) e
525− where
526− fromK1Columns
527− = bimap
528− (fromK1Columns @"Left" @_ @_ @_ @structure1)
529− (fromK1Columns @"Right" @_ @_ @_ @structure2)
530− . fromHEitherTable
531− . hunlabel unlabeler
532− toK1Columns
533− = hlabel labeler
534− . toHEitherTable
535− . bimap
536− (toK1Columns @"Left" @_ @_ @_ @structure1)
537− (toK1Columns @"Right" @_ @_ @_ @structure2)
538− {-# INLINABLE fromK1Columns #-}
539− {-# INLINABLE toK1Columns #-}
540−
541−
542−instance
543− ( HTable (K1Columns "Left" structure1)
544− , HTable (K1Columns "Right" structure2)
545− , K1Table "Left" 'False context (IsStructure structure1) structure1 a
546− , K1Table "Right" 'False context (IsStructure structure2) structure2 b
547− , IsSpecialContext context ~ 'False
548− , Labelable context
549− , Nullifiable context
550− , e ~ EitherTable a b
551− ) => K1Table label 'False context 'True (Shape2 'Either structure1 structure2) e
552− where
553− fromK1Columns =
554− fromColumns2
555− (fromK1Columns @"Left" @_ @_ @_ @structure1)
556− (fromK1Columns @"Right" @_ @_ @_ @structure2) .
557− hunlabel unlabeler
558− toK1Columns =
559− hlabel labeler .
560− toColumns2
561− (toK1Columns @"Left" @_ @_ @_ @structure1)
562− (toK1Columns @"Right" @_ @_ @_ @structure2)
563− {-# INLINABLE fromK1Columns #-}
564− {-# INLINABLE toK1Columns #-}
565−
566−
567−instance
568− ( K1Table label 'True Aggregate (IsStructure structure) structure a
569− , Table Aggregate a
570− , K1Columns label structure ~ HLabel label (Columns a)
571− , as ~ ListTable a
572− ) => K1Table label 'True Aggregate 'True (Shape1 'List structure) as
573− where
574− fromK1Columns = fromColumns . hrelabel (hunlabel hunlabeler)
575− toK1Columns = hrelabel (hlabel hlabeler) . toColumns
576− {-# INLINABLE fromK1Columns #-}
577− {-# INLINABLE toK1Columns #-}
578−
579−
580−instance
581− ( K1Table label 'True Expr (IsStructure structure) structure a
582− , Table Expr a
583− , K1Columns label structure ~ HLabel label (Columns a)
584− , as ~ ListTable a
585− ) => K1Table label 'True Expr 'True (Shape1 'List structure) as
586− where
587− fromK1Columns = fromColumns . hrelabel (hunlabel hunlabeler)
588− toK1Columns = hrelabel (hlabel hlabeler) . toColumns
589− {-# INLINABLE fromK1Columns #-}
590− {-# INLINABLE toK1Columns #-}
591−
592−
593−instance
594− ( K1Table label 'True Insertion (IsStructure structure) structure a
595− , Table Insertion a
596− , K1Columns label structure ~ HLabel label (Columns a)
597− , as ~ ListTable a
598− ) => K1Table label 'True Insertion 'True (Shape1 'List structure) as
599− where
600− fromK1Columns = fromColumns . hrelabel (hunlabel hunlabeler)
601− toK1Columns = hrelabel (hlabel hlabeler) . toColumns
602− {-# INLINABLE fromK1Columns #-}
603− {-# INLINABLE toK1Columns #-}
604−
605−
606−instance
607− ( K1Table label 'True Identity (IsStructure structure) structure a
608− , HTable (K1Columns label structure)
609− , as ~ [a]
610− ) => K1Table label 'True Identity 'True (Shape1 'List structure) as
611− where
612− fromK1Columns = fmap (fromK1Columns @label @'True @Identity @_ @structure) . fromHListTable
613− toK1Columns = toHListTable . fmap (toK1Columns @label @'True @Identity @_ @structure)
614− {-# INLINABLE fromK1Columns #-}
615− {-# INLINABLE toK1Columns #-}
616−
617−
618−instance
619− ( K1Table label 'False context (IsStructure structure) structure a
620− , IsSpecialContext context ~ 'False
621− , Table context a
622− , K1Columns label structure ~ HLabel label (Columns a)
623− , Labelable context
624− , as ~ ListTable a
625− ) => K1Table label 'False context 'True (Shape1 'List structure) as
626− where
627− fromK1Columns = fromColumns . hrelabel (hunlabel hunlabeler)
628− toK1Columns = hrelabel (hlabel hlabeler) . toColumns
629− {-# INLINABLE fromK1Columns #-}
630− {-# INLINABLE toK1Columns #-}
631−
632−
633−instance
634− ( HTable (K1Columns "Just" structure)
635− , K1Table "Just" 'True Aggregate (IsStructure structure) structure a
636− , ma ~ MaybeTable a
637− ) => K1Table label 'True Aggregate 'True (Shape1 'Maybe structure) ma
638− where
639− fromK1Columns =
640− fromColumns1 (fromK1Columns @"Just" @_ @_ @_ @structure) .
641− hunlabel unlabeler
642− toK1Columns =
643− hlabel labeler .
644− toColumns1 (toK1Columns @"Just" @_ @_ @_ @structure)
645− {-# INLINABLE fromK1Columns #-}
646− {-# INLINABLE toK1Columns #-}
647−
648−
649−instance
650− ( HTable (K1Columns "Just" structure)
651− , K1Table "Just" 'True Expr (IsStructure structure) structure a
652− , ma ~ MaybeTable a
653− ) => K1Table label 'True Expr 'True (Shape1 'Maybe structure) ma
654− where
655− fromK1Columns =
656− fromColumns1 (fromK1Columns @"Just" @_ @_ @_ @structure) .
657− hunlabel unlabeler
658− toK1Columns =
659− hlabel labeler .
660− toColumns1 (toK1Columns @"Just" @_ @_ @_ @structure)
661− {-# INLINABLE fromK1Columns #-}
662− {-# INLINABLE toK1Columns #-}
663−
664−
665−instance
666− ( HTable (K1Columns "Just" structure)
667− , K1Table "Just" 'True Insertion (IsStructure structure) structure a
668− , ma ~ MaybeTable a
669− ) => K1Table label 'True Insertion 'True (Shape1 'Maybe structure) ma
670− where
671− fromK1Columns =
672− fromColumns1 (fromK1Columns @"Just" @_ @_ @_ @structure) .
673− hunlabel unlabeler
674− toK1Columns =
675− hlabel labeler .
676− toColumns1 (toK1Columns @"Just" @_ @_ @_ @structure)
677− {-# INLINABLE fromK1Columns #-}
678− {-# INLINABLE toK1Columns #-}
679−
680−
681−instance
682− ( HTable (K1Columns "Just" structure)
683− , K1Table "Just" 'True Identity (IsStructure structure) structure a
684− , ma ~ Maybe a
685− ) => K1Table label 'True Identity 'True (Shape1 'Maybe structure) ma
686− where
687− fromK1Columns
688− = fmap (fromK1Columns @"Just" @_ @_ @_ @structure)
689− . fromHMaybeTable
690− . hunlabel unlabeler
691− toK1Columns
692− = hlabel labeler
693− . toHMaybeTable
694− . fmap (toK1Columns @"Just" @_ @_ @_ @structure)
695− {-# INLINABLE fromK1Columns #-}
696− {-# INLINABLE toK1Columns #-}
697−
698−
699−instance
700− ( HTable (K1Columns "Just" structure)
701− , K1Table "Just" 'False context (IsStructure structure) structure a
702− , IsSpecialContext context ~ 'False
703− , Labelable context
704− , Nullifiable context
705− , ma ~ MaybeTable a
706− ) => K1Table label 'False context 'True (Shape1 'Maybe structure) ma
707− where
708− fromK1Columns =
709− fromColumns1 (fromK1Columns @"Just" @_ @_ @_ @structure) .
710− hunlabel unlabeler
711− toK1Columns =
712− hlabel labeler .
713− toColumns1 (toK1Columns @"Just" @_ @_ @_ @structure)
714− {-# INLINABLE fromK1Columns #-}
715− {-# INLINABLE toK1Columns #-}
716−
717−
718−instance
719− ( K1Table label 'True Aggregate (IsStructure structure) structure a
720− , Table Aggregate a
721− , K1Columns label structure ~ HLabel label (Columns a)
722− , as ~ NonEmptyTable a
723− ) => K1Table label 'True Aggregate 'True (Shape1 'NonEmpty structure) as
724− where
725− fromK1Columns = fromColumns . hrelabel (hunlabel hunlabeler)
726− toK1Columns = hrelabel (hlabel hlabeler) . toColumns
727− {-# INLINABLE fromK1Columns #-}
728− {-# INLINABLE toK1Columns #-}
729−
730−
731−instance
732− ( K1Table label 'True Expr (IsStructure structure) structure a
733− , Table Expr a
734− , K1Columns label structure ~ HLabel label (Columns a)
735− , as ~ NonEmptyTable a
736− ) => K1Table label 'True Expr 'True (Shape1 'NonEmpty structure) as
737− where
738− fromK1Columns = fromColumns . hrelabel (hunlabel hunlabeler)
739− toK1Columns = hrelabel (hlabel hlabeler) . toColumns
740− {-# INLINABLE fromK1Columns #-}
741− {-# INLINABLE toK1Columns #-}
742−
743−
744−instance
745− ( K1Table label 'True Insertion (IsStructure structure) structure a
746− , Table Insertion a
747− , K1Columns label structure ~ HLabel label (Columns a)
748− , as ~ NonEmptyTable a
749− ) => K1Table label 'True Insertion 'True (Shape1 'NonEmpty structure) as
750− where
751− fromK1Columns = fromColumns . hrelabel (hunlabel hunlabeler)
752− toK1Columns = hrelabel (hlabel hlabeler) . toColumns
753− {-# INLINABLE fromK1Columns #-}
754− {-# INLINABLE toK1Columns #-}
755−
756−
757−instance
758− ( K1Table label 'True Identity (IsStructure structure) structure a
759− , HTable (K1Columns label structure)
760− , as ~ NonEmpty a
761− ) => K1Table label 'True Identity 'True (Shape1 'NonEmpty structure) as
762− where
763− fromK1Columns = fmap (fromK1Columns @label @'True @Identity @_ @structure) . fromHNonEmptyTable
764− toK1Columns = toHNonEmptyTable . fmap (toK1Columns @label @'True @Identity @_ @structure)
765− {-# INLINABLE fromK1Columns #-}
766− {-# INLINABLE toK1Columns #-}
767−
768−
769−instance
770− ( K1Table label 'False context (IsStructure structure) structure a
771− , IsSpecialContext context ~ 'False
772− , Table context a
773− , K1Columns label structure ~ HLabel label (Columns a)
774− , Labelable context
775− , as ~ NonEmptyTable a
776− ) => K1Table label 'False context 'True (Shape1 'NonEmpty structure) as
777− where
778− fromK1Columns = fromColumns . hrelabel (hunlabel hunlabeler)
779− toK1Columns = hrelabel (hlabel hlabeler) . toColumns
780− {-# INLINABLE fromK1Columns #-}
781− {-# INLINABLE toK1Columns #-}
782−
783−
784−instance
785− ( HTable (K1Columns "Here" structure1)
786− , HTable (K1Columns "There" structure2)
787− , K1Table "Here" 'True Aggregate (IsStructure structure1) structure1 a
788− , K1Table "There" 'True Aggregate (IsStructure structure2) structure2 b
789− , e ~ TheseTable a b
790− ) => K1Table label 'True Aggregate 'True (Shape2 'These structure1 structure2) e
791− where
792− fromK1Columns =
793− fromColumns2
794− (fromK1Columns @"Here" @_ @_ @_ @structure1)
795− (fromK1Columns @"There" @_ @_ @_ @structure2) .
796− hunlabel unlabeler
797− toK1Columns =
798− hlabel labeler .
799− toColumns2
800− (toK1Columns @"Here" @_ @_ @_ @structure1)
801− (toK1Columns @"There" @_ @_ @_ @structure2)
802− {-# INLINABLE fromK1Columns #-}
803− {-# INLINABLE toK1Columns #-}
804−
805−
806−instance
807− ( HTable (K1Columns "Here" structure1)
808− , HTable (K1Columns "There" structure2)
809− , K1Table "Here" 'True Expr (IsStructure structure1) structure1 a
810− , K1Table "There" 'True Expr (IsStructure structure2) structure2 b
811− , e ~ TheseTable a b
812− ) => K1Table label 'True Expr 'True (Shape2 'These structure1 structure2) e
813− where
814− fromK1Columns =
815− fromColumns2
816− (fromK1Columns @"Here" @_ @_ @_ @structure1)
817− (fromK1Columns @"There" @_ @_ @_ @structure2) .
818− hunlabel unlabeler
819− toK1Columns =
820− hlabel labeler .
821− toColumns2
822− (toK1Columns @"Here" @_ @_ @_ @structure1)
823− (toK1Columns @"There" @_ @_ @_ @structure2)
824− {-# INLINABLE fromK1Columns #-}
825− {-# INLINABLE toK1Columns #-}
826−
827−
828−instance
829− ( HTable (K1Columns "Here" structure1)
830− , HTable (K1Columns "There" structure2)
831− , K1Table "Here" 'True Insertion (IsStructure structure1) structure1 a
832− , K1Table "There" 'True Insertion (IsStructure structure2) structure2 b
833− , e ~ TheseTable a b
834− ) => K1Table label 'True Insertion 'True (Shape2 'These structure1 structure2) e
835− where
836− fromK1Columns =
837− fromColumns2
838− (fromK1Columns @"Here" @_ @_ @_ @structure1)
839− (fromK1Columns @"There" @_ @_ @_ @structure2) .
840− hunlabel unlabeler
841− toK1Columns =
842− hlabel labeler .
843− toColumns2
844− (toK1Columns @"Here" @_ @_ @_ @structure1)
845− (toK1Columns @"There" @_ @_ @_ @structure2)
846− {-# INLINABLE fromK1Columns #-}
847− {-# INLINABLE toK1Columns #-}
848−
849−
850−instance
851− ( HTable (K1Columns "Here" structure1)
852− , HTable (K1Columns "There" structure2)
853− , K1Table "Here" 'True Identity (IsStructure structure1) structure1 a
854− , K1Table "There" 'True Identity (IsStructure structure2) structure2 b
855− , e ~ These a b
856− ) => K1Table label 'True Identity 'True (Shape2 'These structure1 structure2) e
857− where
858− fromK1Columns
859− = bimap
860− (fromK1Columns @"Here" @_ @_ @_ @structure1)
861− (fromK1Columns @"There" @_ @_ @_ @structure2)
862− . fromHTheseTable
863− . hunlabel unlabeler
864− toK1Columns
865− = hlabel labeler
866− . toHTheseTable
867− . bimap
868− (toK1Columns @"Here" @_ @_ @_ @structure1)
869− (toK1Columns @"There" @_ @_ @_ @structure2)
870− {-# INLINABLE fromK1Columns #-}
871− {-# INLINABLE toK1Columns #-}
872−
873−
874−instance
875− ( HTable (K1Columns "Here" structure1)
876− , HTable (K1Columns "There" structure2)
877− , K1Table "Here" 'False context (IsStructure structure1) structure1 a
878− , K1Table "There" 'False context (IsStructure structure2) structure2 b
879− , IsSpecialContext context ~ 'False
880− , Labelable context
881− , Nullifiable context
882− , e ~ TheseTable a b
883− ) => K1Table label 'False context 'True (Shape2 'These structure1 structure2) e
884− where
885− fromK1Columns =
886− fromColumns2
887− (fromK1Columns @"Here" @_ @_ @_ @structure1)
888− (fromK1Columns @"There" @_ @_ @_ @structure2) .
889− hunlabel unlabeler
890− toK1Columns =
891− hlabel labeler .
892− toColumns2
893− (toK1Columns @"Here" @_ @_ @_ @structure1)
894− (toK1Columns @"There" @_ @_ @_ @structure2)
895− {-# INLINABLE fromK1Columns #-}
896− {-# INLINABLE toK1Columns #-}
897−
898−
899−
900−instance
901− ( K1Table "fst" isSpecialContext context (IsStructure structure1) structure1 a1
902− , K1Table "snd" isSpecialContext context (IsStructure structure2) structure2 a2
903− , HTable (K1Columns "fst" structure1)
904− , HTable (K1Columns "snd" structure2)
905− , Labelable context
906− , a ~ (a1, a2)
907− ) => K1Table label isSpecialContext context 'True (structure1, structure2) a
908− where
909− fromK1Columns (hunlabel unlabeler -> (HPair a b)) =
910− ( fromK1Columns @"fst" @_ @_ @_ @structure1 a
911− , fromK1Columns @"snd" @_ @_ @_ @structure2 b
912− )
913− toK1Columns (a, b) = hlabel labeler $ HPair
914− { hfst = toK1Columns @"fst" @_ @_ @_ @structure1 a
915− , hsnd = toK1Columns @"snd" @_ @_ @_ @structure2 b
916− }
917− {-# INLINABLE fromK1Columns #-}
918− {-# INLINABLE toK1Columns #-}
919−
920−
921−instance
922− ( K1Table "fst" isSpecialContext context (IsStructure structure1) structure1 a1
923− , K1Table "snd" isSpecialContext context (IsStructure structure2) structure2 a2
924− , K1Table "trd" isSpecialContext context (IsStructure structure3) structure3 a3
925− , HTable (K1Columns "fst" structure1)
926− , HTable (K1Columns "snd" structure2)
927− , HTable (K1Columns "trd" structure3)
928− , Labelable context
929− , a ~ (a1, a2, a3)
930− ) => K1Table label isSpecialContext context 'True (structure1, structure2, structure3) a
931− where
932− fromK1Columns (hunlabel unlabeler -> (HTrio a b c)) =
933− ( fromK1Columns @"fst" @_ @_ @_ @structure1 a
934− , fromK1Columns @"snd" @_ @_ @_ @structure2 b
935− , fromK1Columns @"trd" @_ @_ @_ @structure3 c
936− )
937− toK1Columns (a, b, c) = hlabel labeler $ HTrio
938− { hfst = toK1Columns @"fst" @_ @_ @_ @structure1 a
939− , hsnd = toK1Columns @"snd" @_ @_ @_ @structure2 b
940− , htrd = toK1Columns @"trd" @_ @_ @_ @structure3 c
941− }
942− {-# INLINABLE fromK1Columns #-}
943− {-# INLINABLE toK1Columns #-}
944−
945−
946−instance
947− ( K1Table "fst" isSpecialContext context (IsStructure structure1) structure1 a1
948− , K1Table "snd" isSpecialContext context (IsStructure structure2) structure2 a2
949− , K1Table "trd" isSpecialContext context (IsStructure structure3) structure3 a3
950− , K1Table "frt" isSpecialContext context (IsStructure structure3) structure4 a4
951− , HTable (K1Columns "fst" structure1)
952− , HTable (K1Columns "snd" structure2)
953− , HTable (K1Columns "trd" structure3)
954− , HTable (K1Columns "frt" structure4)
955− , Labelable context
956− , a ~ (a1, a2, a3, a4)
957− ) => K1Table label isSpecialContext context 'True (structure1, structure2, structure3, structure4) a
958− where
959− fromK1Columns (hunlabel unlabeler -> (HQuartet a b c d)) =
960− ( fromK1Columns @"fst" @_ @_ @_ @structure1 a
961− , fromK1Columns @"snd" @_ @_ @_ @structure2 b
962− , fromK1Columns @"trd" @_ @_ @_ @structure3 c
963− , fromK1Columns @"frt" @_ @_ @_ @structure4 d
964− )
965− toK1Columns (a, b, c, d) = hlabel labeler $ HQuartet
966− { hfst = toK1Columns @"fst" @_ @_ @_ @structure1 a
967− , hsnd = toK1Columns @"snd" @_ @_ @_ @structure2 b
968− , htrd = toK1Columns @"trd" @_ @_ @_ @structure3 c
969− , hfrt = toK1Columns @"frt" @_ @_ @_ @structure4 d
970− }
971− {-# INLINABLE fromK1Columns #-}
972− {-# INLINABLE toK1Columns #-}
973−
974−
975−instance
976− ( K1Table "fst" isSpecialContext context (IsStructure structure1) structure1 a1
977− , K1Table "snd" isSpecialContext context (IsStructure structure2) structure2 a2
978− , K1Table "trd" isSpecialContext context (IsStructure structure3) structure3 a3
979− , K1Table "frt" isSpecialContext context (IsStructure structure3) structure4 a4
980− , K1Table "fft" isSpecialContext context (IsStructure structure3) structure5 a5
981− , HTable (K1Columns "fst" structure1)
982− , HTable (K1Columns "snd" structure2)
983− , HTable (K1Columns "trd" structure3)
984− , HTable (K1Columns "frt" structure4)
985− , HTable (K1Columns "fft" structure5)
986− , Labelable context
987− , a ~ (a1, a2, a3, a4, a5)
988− ) => K1Table label isSpecialContext context 'True (structure1, structure2, structure3, structure4, structure5) a
989− where
990− fromK1Columns (hunlabel unlabeler -> (HQuintet a b c d e)) =
991− ( fromK1Columns @"fst" @_ @_ @_ @structure1 a
992− , fromK1Columns @"snd" @_ @_ @_ @structure2 b
993− , fromK1Columns @"trd" @_ @_ @_ @structure3 c
994− , fromK1Columns @"frt" @_ @_ @_ @structure4 d
995− , fromK1Columns @"fft" @_ @_ @_ @structure5 e
996− )
997− toK1Columns (a, b, c, d, e) = hlabel labeler $ HQuintet
998− { hfst = toK1Columns @"fst" @_ @_ @_ @structure1 a
999− , hsnd = toK1Columns @"snd" @_ @_ @_ @structure2 b
1000− , htrd = toK1Columns @"trd" @_ @_ @_ @structure3 c
1001− , hfrt = toK1Columns @"frt" @_ @_ @_ @structure4 d
1002− , hfft = toK1Columns @"fft" @_ @_ @_ @structure5 e
1003− }
1004− {-# INLINABLE fromK1Columns #-}
1005− {-# INLINABLE toK1Columns #-}
1006−
1007−
1008−instance
1009− ( IsSpecialContext context ~ isSpecialContext
1010− , IsStructure structure ~ 'False
1011− , K1Columns label structure ~ HLabel label (Columns structure)
1012− , Columns structure ~ Columns a
1013− , Labelable context
1014− , Table context a
1015− ) => K1Table label isSpecialContext context 'False structure a
1016− where
1017− fromK1Columns = fromColumns . hunlabel unlabeler
1018− toK1Columns = hlabel labeler . toColumns
1019− {-# INLINABLE fromK1Columns #-}
1020− {-# INLINABLE toK1Columns #-}
src/Rel8/Schema/Generic/Test.hsdeleted−79
@@ -1,79 +0,0 @@
1−{-# language DataKinds #-}
2−{-# language DeriveAnyClass #-}
3−{-# language DeriveGeneric #-}
4−{-# language DerivingStrategies #-}
5−{-# language DuplicateRecordFields #-}
6−
7−{-# options_ghc -O0 #-}
8−
9−module Rel8.Schema.Generic.Test
10− ( module Rel8.Schema.Generic.Test
11− )
12−where
13−
14−-- base
15−import GHC.Generics ( Generic )
16−import Prelude
17−
18−-- rel8
19−import Rel8.Schema.Column
20−import Rel8.Schema.Generic
21−
22−-- text
23−import Data.Text ( Text )
24−
25−
26−data Table f = Table
27− { foo :: Column f (Label "blah" Bool)
28− , bar :: Column f (Maybe Bool)
29− }
30− deriving stock Generic
31− deriving anyclass Rel8able
32−
33−
34−data TablePair f = TablePair
35− { foo :: Column f (Default Bool)
36− , bars :: (Column f Text, Column f Text)
37− }
38− deriving stock Generic
39− deriving anyclass Rel8able
40−
41−
42−data TableMaybe f = TableMaybe
43− { foo :: Column f (Label "ABC" [Maybe Bool])
44− , bars :: HMaybe f (TablePair f, TablePair f)
45− }
46− deriving stock Generic
47− deriving anyclass Rel8able
48−
49−
50−data TableEither f = TableEither
51− { foo :: Column f Bool
52− , bars :: HEither f (HMaybe f (TablePair f, TablePair f)) (Column f (Label "XYZ" Char))
53− }
54− deriving stock Generic
55− deriving anyclass Rel8able
56−
57−
58−data TableThese f = TableThese
59− { foo :: Column f Bool
60− , bars :: HThese f (TableMaybe f) (TableEither f)
61− }
62− deriving stock Generic
63− deriving anyclass Rel8able
64−
65−
66−data TableList f = TableList
67− { foo :: Column f Bool
68− , bars :: HList f (TableThese f)
69− }
70− deriving stock Generic
71− deriving anyclass Rel8able
72−
73−
74−data TableNonEmpty f = TableNonEmpty
75− { foo :: Column f Bool
76− , bars :: HNonEmpty f (TableList f)
77− }
78− deriving stock Generic
79− deriving anyclass Rel8able
src/Rel8/Schema/HTable.hs+74−38
@@ -16,13 +16,12 @@
16module Rel8.Schema.HTable
16module Rel8.Schema.HTable
17 ( HTable (HField, HConstrainTable)
17 ( HTable (HField, HConstrainTable)
18 , hfield, htabulate, htraverse, hdicts, hspecs
18 , hfield, htabulate, htraverse, hdicts, hspecs
19− , htabulateA
19+ , hfoldMap, hmap, htabulateA, htraverseP, htraversePWithField
20−
21− , HPair(..)
22 )
20 )
23where
21where
24
22
25-- base
23-- base
24+import Data.Functor.Const ( Const( Const ), getConst )
26import Data.Kind ( Constraint, Type )
25import Data.Kind ( Constraint, Type )
27import Data.Functor.Compose ( Compose( Compose ), getCompose )
26import Data.Functor.Compose ( Compose( Compose ), getCompose )
28import Data.Proxy ( Proxy )
27import Data.Proxy ( Proxy )
@@ -34,26 +33,37 @@ import GHC.Generics
34 )
33 )
35import Prelude
34import Prelude
36
35
36+-- profunctors
37+import Data.Profunctor ( rmap, Profunctor (lmap) )
38+
39+-- product-profunctors
40+import Data.Profunctor.Product ( ProductProfunctor ((****)) )
41+
37-- rel8
42-- rel8
38import Rel8.Schema.Dict ( Dict )
43import Rel8.Schema.Dict ( Dict )
39−import Rel8.Schema.Spec ( Spec, SSpec )
44+import Rel8.Schema.Spec ( Spec )
40−import Rel8.Schema.HTable.Pair ( HPair( HPair ) )
45+import Rel8.Schema.HTable.Product ( HProduct( HProduct ) )
41import qualified Rel8.Schema.Kind as K
46import qualified Rel8.Schema.Kind as K
42
47
43-- semigroupoids
48-- semigroupoids
44import Data.Functor.Apply ( Apply, (<.>) )
49import Data.Functor.Apply ( Apply, (<.>) )
45
50
46−
51+-- | A @HTable@ is a functor-indexed/higher-kinded data type that is
52+-- representable ('htabulate'/'hfield'), constrainable ('hdicts'), and
53+-- specified ('hspecs').
54+--
55+-- This is an internal concept for Rel8, and you should not need to define
56+-- instances yourself or specify this constraint.
47type HTable :: K.HTable -> Constraint
57type HTable :: K.HTable -> Constraint
48class HTable t where
58class HTable t where
49− type HField t = (field :: Spec -> Type) | field -> t
59+ type HField t = (field :: Type -> Type) | field -> t
50− type HConstrainTable t (c :: Spec -> Constraint) :: Constraint
60+ type HConstrainTable t (c :: Type -> Constraint) :: Constraint
51
61
52− hfield :: t context -> HField t spec -> context spec
62+ hfield :: t context -> HField t a -> context a
53− htabulate :: (forall spec. HField t spec -> context spec) -> t context
63+ htabulate :: (forall a. HField t a -> context a) -> t context
54− htraverse :: Apply m => (forall spec. f spec -> m (g spec)) -> t f -> m (t g)
64+ htraverse :: Apply m => (forall a. f a -> m (g a)) -> t f -> m (t g)
55 hdicts :: HConstrainTable t c => t (Dict c)
65 hdicts :: HConstrainTable t c => t (Dict c)
56− hspecs :: t SSpec
66+ hspecs :: t Spec
57
67
58 type HField t = GHField t
68 type HField t = GHField t
59 type HConstrainTable t c = HConstrainTable (GHColumns (Rep (t Proxy))) c
69 type HConstrainTable t c = HConstrainTable (GHColumns (Rep (t Proxy))) c
@@ -64,7 +74,7 @@ class HTable t where
64 , HField (GHColumns (Rep (t Proxy))) ~ HField (GHColumns (Rep (t context)))
74 , HField (GHColumns (Rep (t Proxy))) ~ HField (GHColumns (Rep (t context)))
65 , GHTable context (Rep (t context))
75 , GHTable context (Rep (t context))
66 )
76 )
67− => t context -> HField t spec -> context spec
77+ => t context -> HField t a -> context a
68 hfield table (GHField field) = hfield (toGHColumns (from table)) field
78 hfield table (GHField field) = hfield (toGHColumns (from table)) field
69
79
70 default htabulate ::
80 default htabulate ::
@@ -73,7 +83,7 @@ class HTable t where
73 , HField (GHColumns (Rep (t Proxy))) ~ HField (GHColumns (Rep (t context)))
83 , HField (GHColumns (Rep (t Proxy))) ~ HField (GHColumns (Rep (t context)))
74 , GHTable context (Rep (t context))
84 , GHTable context (Rep (t context))
75 )
85 )
76− => (forall spec. HField t spec -> context spec) -> t context
86+ => (forall a. HField t a -> context a) -> t context
77 htabulate f = to $ fromGHColumns $ htabulate (f . GHField)
87 htabulate f = to $ fromGHColumns $ htabulate (f . GHField)
78
88
79 default htraverse
89 default htraverse
@@ -83,7 +93,7 @@ class HTable t where
83 , Generic (t g), GHTable g (Rep (t g))
93 , Generic (t g), GHTable g (Rep (t g))
84 , GHColumns (Rep (t f)) ~ GHColumns (Rep (t g))
94 , GHColumns (Rep (t f)) ~ GHColumns (Rep (t g))
85 )
95 )
86− => (forall spec. f spec -> m (g spec)) -> t f -> m (t g)
96+ => (forall a. f a -> m (g a)) -> t f -> m (t g)
87 htraverse f = fmap (to . fromGHColumns) . htraverse f . toGHColumns . from
97 htraverse f = fmap (to . fromGHColumns) . htraverse f . toGHColumns . from
88
98
89 default hdicts
99 default hdicts
@@ -97,10 +107,10 @@ class HTable t where
97 hdicts = to $ fromGHColumns (hdicts @(GHColumns (Rep (t Proxy))) @c)
107 hdicts = to $ fromGHColumns (hdicts @(GHColumns (Rep (t Proxy))) @c)
98
108
99 default hspecs ::
109 default hspecs ::
100− ( Generic (t SSpec)
110+ ( Generic (t Spec)
101− , GHTable SSpec (Rep (t SSpec))
111+ , GHTable Spec (Rep (t Spec))
102 )
112 )
103− => t SSpec
113+ => t Spec
104 hspecs = to $ fromGHColumns hspecs
114 hspecs = to $ fromGHColumns hspecs
105
115
106 {-# INLINABLE hfield #-}
116 {-# INLINABLE hfield #-}
@@ -110,17 +120,43 @@ class HTable t where
110 {-# INLINABLE hspecs #-}
120 {-# INLINABLE hspecs #-}
111
121
112
122
123+hfoldMap :: (HTable t, Semigroup s)
124+ => (forall a. context a -> s) -> t context -> s
125+hfoldMap f a = getConst $ htraverse (Const . f) a
126+
127+
128+hmap :: HTable t
129+ => (forall a. context a -> context' a) -> t context -> t context'
130+hmap f a = htabulate $ \field -> f (hfield a field)
131+
132+
113htabulateA :: (HTable t, Apply m)
133htabulateA :: (HTable t, Apply m)
114− => (forall spec. HField t spec -> m (context spec)) -> m (t context)
134+ => (forall a. HField t a -> m (context a)) -> m (t context)
115htabulateA f = htraverse getCompose $ htabulate $ Compose . f
135htabulateA f = htraverse getCompose $ htabulate $ Compose . f
116{-# INLINABLE htabulateA #-}
136{-# INLINABLE htabulateA #-}
117
137
138+newtype ApplyP p a b = ApplyP { unApplyP :: p a b }
139+
140+instance Profunctor p => Functor (ApplyP p a) where
141+ fmap f = ApplyP . rmap f . unApplyP
142+
143+instance ProductProfunctor p => Apply (ApplyP p a) where
144+ ApplyP f <.> ApplyP x = ApplyP (rmap id f **** x)
145+
146+htraverseP :: (HTable t, ProductProfunctor p)
147+ => (forall a. p (f a) (g a)) -> p (t f) (t g)
148+htraverseP f = htraversePWithField (const f)
149+
150+htraversePWithField :: (HTable t, ProductProfunctor p)
151+ => (forall a. HField t a -> p (f a) (g a)) -> p (t f) (t g)
152+htraversePWithField f = unApplyP $ htabulateA $ \field -> ApplyP $
153+ lmap (flip hfield field) (f field)
118
154
119−type GHField :: K.HTable -> Spec -> Type
155+type GHField :: K.HTable -> Type -> Type
120−newtype GHField t spec = GHField (HField (GHColumns (Rep (t Proxy))) spec)
156+newtype GHField t a = GHField (HField (GHColumns (Rep (t Proxy))) a)
121
157
122
158
123−type GHTable :: K.HContext -> (Type -> Type) -> Constraint
159+type GHTable :: K.Context -> (Type -> Type) -> Constraint
124class HTable (GHColumns rep) => GHTable context rep | rep -> context where
160class HTable (GHColumns rep) => GHTable context rep | rep -> context where
125 type GHColumns rep :: K.HTable
161 type GHColumns rep :: K.HTable
126 toGHColumns :: rep x -> GHColumns rep context
162 toGHColumns :: rep x -> GHColumns rep context
@@ -140,30 +176,30 @@ instance HTable table => GHTable context (K1 i (table context)) where
140
176
141
177
142instance (GHTable context a, GHTable context b) => GHTable context (a :*: b) where
178instance (GHTable context a, GHTable context b) => GHTable context (a :*: b) where
143− type GHColumns (a :*: b) = HPair (GHColumns a) (GHColumns b)
179+ type GHColumns (a :*: b) = HProduct (GHColumns a) (GHColumns b)
144− toGHColumns (a :*: b) = HPair (toGHColumns a) (toGHColumns b)
180+ toGHColumns (a :*: b) = HProduct (toGHColumns a) (toGHColumns b)
145− fromGHColumns (HPair a b) = fromGHColumns a :*: fromGHColumns b
181+ fromGHColumns (HProduct a b) = fromGHColumns a :*: fromGHColumns b
146
182
147
183
148−-- | A HField type for indexing into HPair.
184+-- | A HField type for indexing into HProduct.
149−type HPairField :: K.HTable -> K.HTable -> Spec -> Type
185+type HProductField :: K.HTable -> K.HTable -> Type -> Type
150−data HPairField x y spec
186+data HProductField x y a
151− = HFst (HField x spec)
187+ = HFst (HField x a)
152− | HSnd (HField y spec)
188+ | HSnd (HField y a)
153
189
154
190
155−instance (HTable x, HTable y) => HTable (HPair x y) where
191+instance (HTable x, HTable y) => HTable (HProduct x y) where
156− type HConstrainTable (HPair x y) c = (HConstrainTable x c, HConstrainTable y c)
192+ type HConstrainTable (HProduct x y) c = (HConstrainTable x c, HConstrainTable y c)
157− type HField (HPair x y) = HPairField x y
193+ type HField (HProduct x y) = HProductField x y
158
194
159− hfield (HPair l r) = \case
195+ hfield (HProduct l r) = \case
160 HFst i -> hfield l i
196 HFst i -> hfield l i
161 HSnd i -> hfield r i
197 HSnd i -> hfield r i
162
198
163− htabulate f = HPair (htabulate (f . HFst)) (htabulate (f . HSnd))
199+ htabulate f = HProduct (htabulate (f . HFst)) (htabulate (f . HSnd))
164− htraverse f (HPair x y) = HPair <$> htraverse f x <.> htraverse f y
200+ htraverse f (HProduct x y) = HProduct <$> htraverse f x <.> htraverse f y
165− hdicts = HPair hdicts hdicts
201+ hdicts = HProduct hdicts hdicts
166− hspecs = HPair hspecs hspecs
202+ hspecs = HProduct hspecs hspecs
167
203
168 {-# INLINABLE hfield #-}
204 {-# INLINABLE hfield #-}
169 {-# INLINABLE htabulate #-}
205 {-# INLINABLE htabulate #-}
src/Rel8/Schema/HTable/Either.hs+5−6
@@ -14,20 +14,19 @@ import GHC.Generics ( Generic )
14import Prelude ()
14import Prelude ()
15
15
16-- rel8
16-- rel8
17−import Rel8.Kind.Necessity ( Necessity( Required ) )
18import Rel8.Schema.HTable ( HTable )
17import Rel8.Schema.HTable ( HTable )
19−import Rel8.Schema.HTable.Identity ( HIdentity(..) )
18+import Rel8.Schema.HTable.Identity ( HIdentity )
19+import Rel8.Schema.HTable.Label ( HLabel )
20import Rel8.Schema.HTable.Nullify ( HNullify )
20import Rel8.Schema.HTable.Nullify ( HNullify )
21import qualified Rel8.Schema.Kind as K
21import qualified Rel8.Schema.Kind as K
22−import Rel8.Schema.Spec ( Spec( Spec ) )
23import Rel8.Type.Tag ( EitherTag )
22import Rel8.Type.Tag ( EitherTag )
24
23
25
24
26type HEitherTable :: K.HTable -> K.HTable -> K.HTable
25type HEitherTable :: K.HTable -> K.HTable -> K.HTable
27data HEitherTable left right context = HEitherTable
26data HEitherTable left right context = HEitherTable
28− { htag :: HIdentity ('Spec '["isRight"] 'Required EitherTag EitherTag) context
27+ { htag :: HLabel "isRight" (HIdentity EitherTag) context
29− , hleft :: HNullify left context
28+ , hleft :: HLabel "Left" (HNullify left) context
30− , hright :: HNullify right context
29+ , hright :: HLabel "Right" (HNullify right) context
31 }
30 }
32 deriving stock Generic
31 deriving stock Generic
33 deriving anyclass HTable
32 deriving anyclass HTable
src/Rel8/Schema/HTable/Identity.hs+16−17
@@ -1,15 +1,17 @@
1{-# language DataKinds #-}
1{-# language DataKinds #-}
2−{-# language GADTs #-}
2+{-# language FlexibleContexts #-}
3{-# language StandaloneKindSignatures #-}
3{-# language StandaloneKindSignatures #-}
4{-# language TypeFamilies #-}
4{-# language TypeFamilies #-}
5+{-# language UndecidableInstances #-}
5
6
6module Rel8.Schema.HTable.Identity
7module Rel8.Schema.HTable.Identity
7− ( HIdentity(..)
8+ ( HIdentity( HIdentity, unHIdentity )
8 )
9 )
9where
10where
10
11
11-- base
12-- base
12import Data.Kind ( Type )
13import Data.Kind ( Type )
14+import Data.Type.Equality ( (:~:)( Refl ) )
13import Prelude
15import Prelude
14
16
15-- rel8
17-- rel8
@@ -19,26 +21,23 @@ import Rel8.Schema.HTable
19 , hfield, htabulate, htraverse, hdicts, hspecs
21 , hfield, htabulate, htraverse, hdicts, hspecs
20 )
22 )
21import qualified Rel8.Schema.Kind as K
23import qualified Rel8.Schema.Kind as K
22−import Rel8.Schema.Spec ( Spec, KnownSpec, specSing )
24+import Rel8.Schema.Null ( Sql )
25+import Rel8.Schema.Spec ( specification )
26+import Rel8.Type ( DBType )
23
27
24
28
25−type HIdentity :: Spec -> K.HTable
29+type HIdentity :: Type -> K.HTable
26−newtype HIdentity spec context = HIdentity
30+newtype HIdentity a context = HIdentity
27− { unHIdentity :: context spec
31+ { unHIdentity :: context a
28 }
32 }
29
33
30
34
31−type HIdentityField :: Spec -> Spec -> Type
35+instance Sql DBType a => HTable (HIdentity a) where
32−data HIdentityField _spec spec where
36+ type HConstrainTable (HIdentity a) constraint = constraint a
33− HIdentityField :: HIdentityField spec spec
37+ type HField (HIdentity a) = (:~:) a
34
38
35−
36−instance KnownSpec spec => HTable (HIdentity spec) where
37− type HConstrainTable (HIdentity spec) c = c spec
38− type HField (HIdentity spec) = HIdentityField spec
39−
40− hfield (HIdentity a) HIdentityField = a
39+ hfield (HIdentity a) Refl = a
41− htabulate f = HIdentity $ f HIdentityField
40+ htabulate f = HIdentity $ f Refl
42 htraverse f (HIdentity a) = HIdentity <$> f a
41 htraverse f (HIdentity a) = HIdentity <$> f a
43 hdicts = HIdentity Dict
42 hdicts = HIdentity Dict
44− hspecs = HIdentity specSing
43+ hspecs = HIdentity specification
src/Rel8/Schema/HTable/Label.hs+31−92
@@ -1,131 +1,70 @@
1−{-# language ConstraintKinds #-}
2{-# language DataKinds #-}
1{-# language DataKinds #-}
3−{-# language FlexibleInstances #-}
4−{-# language GADTs #-}
5−{-# language InstanceSigs #-}
6−{-# language MultiParamTypeClasses #-}
7−{-# language QuantifiedConstraints #-}
8{-# language RankNTypes #-}
2{-# language RankNTypes #-}
9{-# language RecordWildCards #-}
3{-# language RecordWildCards #-}
10{-# language ScopedTypeVariables #-}
4{-# language ScopedTypeVariables #-}
11{-# language StandaloneKindSignatures #-}
5{-# language StandaloneKindSignatures #-}
12{-# language TypeApplications #-}
6{-# language TypeApplications #-}
13{-# language TypeFamilies #-}
7{-# language TypeFamilies #-}
14−{-# language TypeOperators #-}
15−{-# language UndecidableInstances #-}
16
8
17module Rel8.Schema.HTable.Label
9module Rel8.Schema.HTable.Label
18− ( HLabel( HLabel )
19− , hlabel, hunlabel
10+ ( HLabel, hlabel, hrelabel, hunlabel
11+ , hproject
20 )
12 )
21where
13where
22
14
23-- base
15-- base
24−import Data.Kind ( Constraint, Type )
16+import Data.Kind ( Type )
25import Data.Proxy ( Proxy( Proxy ) )
17import Data.Proxy ( Proxy( Proxy ) )
26−import GHC.TypeLits ( KnownSymbol, Symbol )
18+import GHC.TypeLits ( KnownSymbol, Symbol, symbolVal )
27import Prelude
19import Prelude
28
20
29-- rel8
21-- rel8
30−import Rel8.Kind.Labels ( SLabels( SLabels ) )
31−import Rel8.Schema.Dict ( Dict( Dict ) )
32import Rel8.Schema.HTable
22import Rel8.Schema.HTable
33 ( HTable, HConstrainTable, HField
23 ( HTable, HConstrainTable, HField
34− , hfield, htabulate, htraverse, hdicts, hspecs
24+ , htabulate, hfield, htraverse, hdicts, hspecs
35 )
25 )
36import qualified Rel8.Schema.Kind as K
26import qualified Rel8.Schema.Kind as K
37−import Rel8.Schema.Spec ( Spec( Spec ), SSpec(..) )
27+import Rel8.Schema.Spec ( Spec(..) )
38
28
39
29
40type HLabel :: Symbol -> K.HTable -> K.HTable
30type HLabel :: Symbol -> K.HTable -> K.HTable
41−data HLabel label table context where
31+newtype HLabel label table context = HLabel (table context)
42− HLabel :: table (LabelSpec label context) -> HLabel label table context
43
32
44
33
45−type HLabelField :: Symbol -> K.HTable -> Spec -> Type
34+type HLabelField :: Symbol -> K.HTable -> Type -> Type
46−data HLabelField label table spec where
35+newtype HLabelField label table a = HLabelField (HField table a)
47− HLabelField
48− :: HField table ('Spec labels necessity db a)
49− -> HLabelField label table ('Spec (label ': labels) necessity db a)
50
36
51
37
52instance (HTable table, KnownSymbol label) => HTable (HLabel label table) where
38instance (HTable table, KnownSymbol label) => HTable (HLabel label table) where
53 type HField (HLabel label table) = HLabelField label table
39 type HField (HLabel label table) = HLabelField label table
54− type HConstrainTable (HLabel label table) c =
40+ type HConstrainTable (HLabel label table) constraint =
55− HConstrainTable table (LabelSpecC label c)
41+ HConstrainTable table constraint
56−
42+
57− hfield (HLabel table) (HLabelField field) =
43+ hfield (HLabel a) (HLabelField field) = hfield a field
58− getLabelSpec (hfield table field)
59−
60− htabulate f = HLabel $ htabulate $ \field -> case hfield hspecs field of
44+ htabulate f = HLabel (htabulate (f . HLabelField))
61− SSpec {} -> LabelSpec (f (HLabelField field))
62− htraverse f (HLabel t) = HLabel <$> htraverse (traverseLabelSpec f) t
45+ htraverse f (HLabel a) = HLabel <$> htraverse f a
63−
46+ hdicts = HLabel (hdicts @table)
64− hdicts :: forall c. HConstrainTable table (LabelSpecC label c)
65− => HLabel label table (Dict c)
66− hdicts = HLabel $ htabulate $ \field -> case hfield hspecs field of
67− SSpec {} -> case hfield (hdicts @_ @(LabelSpecC label c)) field of
68− Dict -> LabelSpec Dict
69−
70− hspecs = HLabel $ htabulate $ \field -> case hfield hspecs field of
47+ hspecs = HLabel $ htabulate $ \field -> case hfield (hspecs @table) field of
71− SSpec {..} -> LabelSpec SSpec {labels = SLabels Proxy labels, ..}
48+ Spec {..} -> Spec {labels = symbolVal (Proxy @label) : labels, ..}
72−
73− {-# INLINABLE hfield #-}
74− {-# INLINABLE htabulate #-}
75− {-# INLINABLE htraverse #-}
76− {-# INLINABLE hdicts #-}
77 {-# INLINABLE hspecs #-}
49 {-# INLINABLE hspecs #-}
78
50
79
51
80−type LabelingSpec :: Type -> Type
52+hlabel :: forall label t context. t context -> HLabel label t context
81−type LabelingSpec r = Symbol -> (Spec -> r) -> Spec -> r
53+hlabel = HLabel
82−
54+{-# INLINABLE hlabel #-}
83−
84−type LabelSpec :: LabelingSpec Type
85−data LabelSpec label context spec where
86− LabelSpec
87− :: { getLabelSpec :: context ('Spec (label ': labels) necessity db a) }
88− -> LabelSpec label context ('Spec labels necessity db a)
89−
90−
91−type LabelSpecC :: LabelingSpec Constraint
92−class
93− ( forall labels necessity db a.
94− ( spec ~ 'Spec labels necessity db a =>
95− constraint ('Spec (label ': labels) necessity db a)
96− )
97− ) => LabelSpecC label constraint spec
98−instance
99− ( spec ~ 'Spec labels necessity db a
100− , constraint ('Spec (label ': labels) necessity db a)
101− ) => LabelSpecC label constraint spec
102
55
103
56
104−traverseLabelSpec :: forall context context' label spec m. Functor m
57+hrelabel :: forall label' label t context. HLabel label t context -> HLabel label' t context
105− => (forall x. context x -> m (context' x))
58+hrelabel = hlabel . hunlabel
106− -> LabelSpec label context spec -> m (LabelSpec label context' spec)
59+{-# INLINABLE hrelabel #-}
107−traverseLabelSpec f (LabelSpec a) = LabelSpec <$> f a
108
60
109
61
110−hlabel :: HTable t
62+hunlabel :: forall label t context. HLabel label t context -> t context
111− => (forall labels necessity db a. ()
63+hunlabel (HLabel a) = a
112− => context ('Spec labels necessity db a)
113− -> context ('Spec (label ': labels) necessity db a))
114− -> t context
115− -> HLabel label t context
116−hlabel labeler a = HLabel $ htabulate $ \field ->
117− case hfield hspecs field of
118− SSpec {} -> LabelSpec (labeler (hfield a field))
119−{-# INLINABLE hlabel #-}
64+{-# INLINABLE hunlabel #-}
120
65
121
66
122−hunlabel :: HTable t
67+hproject :: ()
123− => (forall labels necessity db a. ()
68+ => (forall ctx. t ctx -> t' ctx)
124− => context ('Spec (label ': labels) necessity db a)
125− -> context ('Spec labels necessity db a))
126− -> HLabel label t context
69+ -> HLabel label t context -> HLabel label t' context
127− -> t context
70+hproject f (HLabel a) = HLabel (f a)
128−hunlabel unlabler (HLabel as) =
129− htabulate $ \field -> case hfield as field of
130− LabelSpec a -> unlabler a
131−{-# INLINABLE hunlabel #-}
src/Rel8/Schema/HTable/MapTable.hsnew file+99
@@ -0,0 +1,99 @@
1+{-# language AllowAmbiguousTypes #-}
2+{-# language BlockArguments #-}
3+{-# language ConstraintKinds #-}
4+{-# language DataKinds #-}
5+{-# language FlexibleInstances #-}
6+{-# language GADTs #-}
7+{-# language InstanceSigs #-}
8+{-# language MultiParamTypeClasses #-}
9+{-# language RankNTypes #-}
10+{-# language ScopedTypeVariables #-}
11+{-# language StandaloneKindSignatures #-}
12+{-# language TypeApplications #-}
13+{-# language TypeFamilies #-}
14+{-# language UndecidableInstances #-}
15+{-# language UndecidableSuperClasses #-}
16+
17+module Rel8.Schema.HTable.MapTable
18+ ( HMapTable(..)
19+ , MapSpec(..)
20+ , Precompose(..)
21+ , HMapTableField(..)
22+ , hproject
23+ )
24+where
25+
26+-- base
27+import Data.Kind ( Constraint, Type )
28+import Prelude
29+
30+-- rel8
31+import Rel8.FCF ( Exp, Eval )
32+import Rel8.Schema.HTable
33+ ( HTable, HConstrainTable, HField
34+ , hfield, htabulate, htraverse, hdicts, hspecs
35+ )
36+import Rel8.Schema.Spec ( Spec )
37+import qualified Rel8.Schema.Kind as K
38+import Rel8.Schema.Dict ( Dict( Dict ) )
39+
40+
41+type HMapTable :: (Type -> Exp Type) -> K.HTable -> K.HTable
42+newtype HMapTable f t context = HMapTable
43+ { unHMapTable :: t (Precompose f context)
44+ }
45+
46+
47+type Precompose :: (Type -> Exp Type) -> K.Context -> K.Context
48+newtype Precompose f g x = Precompose
49+ { precomposed :: g (Eval (f x))
50+ }
51+
52+
53+type HMapTableField :: (Type -> Exp Type) -> K.HTable -> K.Context
54+data HMapTableField f t x where
55+ HMapTableField :: HField t a -> HMapTableField f t (Eval (f a))
56+
57+
58+instance (HTable t, MapSpec f) => HTable (HMapTable f t) where
59+ type HField (HMapTable f t) =
60+ HMapTableField f t
61+
62+ type HConstrainTable (HMapTable f t) c =
63+ HConstrainTable t (ComposeConstraint f c)
64+
65+ hfield (HMapTable x) (HMapTableField i) =
66+ precomposed (hfield x i)
67+
68+ htabulate f =
69+ HMapTable $ htabulate (Precompose . f . HMapTableField)
70+
71+ htraverse f (HMapTable x) =
72+ HMapTable <$> htraverse (fmap Precompose . f . precomposed) x
73+ {-# INLINABLE htraverse #-}
74+
75+ hdicts :: forall c. HConstrainTable (HMapTable f t) c => HMapTable f t (Dict c)
76+ hdicts =
77+ htabulate \(HMapTableField j) ->
78+ case hfield (hdicts @_ @(ComposeConstraint f c)) j of
79+ Dict -> Dict
80+
81+ hspecs =
82+ HMapTable $ htabulate $ Precompose . mapInfo @f . hfield hspecs
83+ {-# INLINABLE hspecs #-}
84+
85+
86+type MapSpec :: (Type -> Exp Type) -> Constraint
87+class MapSpec f where
88+ mapInfo :: Spec x -> Spec (Eval (f x))
89+
90+
91+type ComposeConstraint :: (Type -> Exp Type) -> (Type -> Constraint) -> Type -> Constraint
92+class c (Eval (f a)) => ComposeConstraint f c a
93+instance c (Eval (f a)) => ComposeConstraint f c a
94+
95+
96+hproject :: ()
97+ => (forall ctx. t ctx -> t' ctx)
98+ -> HMapTable f t context -> HMapTable f t' context
99+hproject f (HMapTable a) = HMapTable (f a)
src/Rel8/Schema/HTable/Maybe.hs+4−5
@@ -14,19 +14,18 @@ import GHC.Generics ( Generic )
14import Prelude
14import Prelude
15
15
16-- rel8
16-- rel8
17−import Rel8.Kind.Necessity ( Necessity( Required ) )
18import Rel8.Schema.HTable ( HTable )
17import Rel8.Schema.HTable ( HTable )
19−import Rel8.Schema.HTable.Identity ( HIdentity(..) )
18+import Rel8.Schema.HTable.Identity ( HIdentity )
19+import Rel8.Schema.HTable.Label ( HLabel )
20import Rel8.Schema.HTable.Nullify ( HNullify )
20import Rel8.Schema.HTable.Nullify ( HNullify )
21import qualified Rel8.Schema.Kind as K
21import qualified Rel8.Schema.Kind as K
22−import Rel8.Schema.Spec ( Spec( Spec ) )
23import Rel8.Type.Tag ( MaybeTag )
22import Rel8.Type.Tag ( MaybeTag )
24
23
25
24
26type HMaybeTable :: K.HTable -> K.HTable
25type HMaybeTable :: K.HTable -> K.HTable
27data HMaybeTable table context = HMaybeTable
26data HMaybeTable table context = HMaybeTable
28− { htag :: HIdentity ('Spec '["isJust"] 'Required MaybeTag (Maybe MaybeTag)) context
27+ { htag :: HLabel "isJust" (HIdentity (Maybe MaybeTag)) context
29− , hjust :: HNullify table context
28+ , hjust :: HLabel "Just" (HNullify table) context
30 }
29 }
31 deriving stock Generic
30 deriving stock Generic
32 deriving anyclass HTable
31 deriving anyclass HTable
src/Rel8/Schema/HTable/Nullify.hs+61−89
@@ -1,145 +1,117 @@
1{-# language ConstraintKinds #-}
1{-# language ConstraintKinds #-}
2{-# language DataKinds #-}
2{-# language DataKinds #-}
3+{-# language DeriveAnyClass #-}
4+{-# language DerivingStrategies #-}
5+{-# language DeriveGeneric #-}
3{-# language FlexibleInstances #-}
6{-# language FlexibleInstances #-}
4{-# language GADTs #-}
7{-# language GADTs #-}
5−{-# language InstanceSigs #-}
8+{-# language LambdaCase #-}
6{-# language MultiParamTypeClasses #-}
9{-# language MultiParamTypeClasses #-}
10+{-# language NamedFieldPuns #-}
7{-# language QuantifiedConstraints #-}
11{-# language QuantifiedConstraints #-}
8{-# language RankNTypes #-}
12{-# language RankNTypes #-}
9{-# language RecordWildCards #-}
13{-# language RecordWildCards #-}
10{-# language ScopedTypeVariables #-}
14{-# language ScopedTypeVariables #-}
11{-# language StandaloneKindSignatures #-}
15{-# language StandaloneKindSignatures #-}
12−{-# language TypeApplications #-}
13{-# language TypeFamilies #-}
16{-# language TypeFamilies #-}
14{-# language UndecidableInstances #-}
17{-# language UndecidableInstances #-}
15
18
16module Rel8.Schema.HTable.Nullify
19module Rel8.Schema.HTable.Nullify
17 ( HNullify( HNullify )
20 ( HNullify( HNullify )
21+ , Nullify
22+ , hguard
23+ , hnulls
24+ , hnullify
18− , hnulls, hnullify, hunnullify
25+ , hunnullify
26+ , hproject
19 )
27 )
20where
28where
21
29
22-- base
30-- base
23−import Data.Kind ( Constraint, Type )
31+import Data.Kind ( Type )
32+import GHC.Generics ( Generic )
24import Prelude hiding ( null )
33import Prelude hiding ( null )
25
34
26-- rel8
35-- rel8
27−import Rel8.Schema.Dict ( Dict( Dict ) )
36+import Rel8.FCF ( Eval, Exp )
28−import Rel8.Schema.HTable
29− ( HTable, HConstrainTable, HField
30− , hfield, htabulate, htabulateA, htraverse, hdicts, hspecs
37+import Rel8.Schema.HTable ( HTable, hfield, htabulate, htabulateA, hspecs )
38+import Rel8.Schema.HTable.MapTable
39+ ( HMapTable, HMapTableField( HMapTableField )
40+ , MapSpec, mapInfo
31 )
41 )
42+import qualified Rel8.Schema.HTable.MapTable as HMapTable ( hproject )
32import qualified Rel8.Schema.Kind as K
43import qualified Rel8.Schema.Kind as K
33−import Rel8.Schema.Nullability ( Nullability( Nullable, NonNullable ) )
44+import Rel8.Schema.Null ( Nullity( Null, NotNull ) )
34−import Rel8.Schema.Spec ( Spec( Spec ), SSpec(..) )
45+import qualified Rel8.Schema.Null as Type ( Nullify )
46+import Rel8.Schema.Spec ( Spec(..) )
35
47
36-- semigroupoids
48-- semigroupoids
37import Data.Functor.Apply ( Apply )
49import Data.Functor.Apply ( Apply )
38
50
39
51
40type HNullify :: K.HTable -> K.HTable
52type HNullify :: K.HTable -> K.HTable
41−newtype HNullify table context = HNullify (table (NullifySpec context))
53+newtype HNullify table context = HNullify (HMapTable Nullify table context)
54+ deriving stock Generic
55+ deriving anyclass HTable
42
56
43
57
44−type HNullifyField :: K.HTable -> Spec -> Type
58+-- | Transform a 'Type' by allowing it to be @null@.
45−data HNullifyField table spec where
59+data Nullify :: Type -> Exp Type
46− HNullifyField
60+type instance Eval (Nullify a) = Type.Nullify a
47− :: HField table ('Spec labels necessity dbType a)
48− -> HNullifyField table ('Spec labels necessity dbType (Maybe dbType))
49
61
50
62
51−instance HTable table => HTable (HNullify table) where
63+instance MapSpec Nullify where
52− type HField (HNullify table) = HNullifyField table
64+ mapInfo = \case
53− type HConstrainTable (HNullify table) c =
65+ Spec {nullity, ..} -> Spec
54− HConstrainTable table (NullifySpecC c)
66+ { nullity = case nullity of
67+ Null -> Null
68+ NotNull -> Null
69+ , ..
70+ }
55
71
56− hfield (HNullify table) (HNullifyField field) =
57− getNullifySpec (hfield table field)
58
72
59− htabulate f = HNullify $ htabulate $ \field -> case hfield hspecs field of
73+hguard :: HTable t
60− SSpec {} -> NullifySpec (f (HNullifyField field))
74+ => (forall a. context (Maybe a) -> context (Maybe a))
61−
75+ -> HNullify t context -> HNullify t context
62− htraverse f (HNullify t) = HNullify <$> htraverse (traverseNullifySpec f) t
76+hguard guarder (HNullify as) = HNullify $ htabulate $ \(HMapTableField field) ->
63−
64− hdicts :: forall c. HConstrainTable table (NullifySpecC c)
65− => HNullify table (Dict c)
66− hdicts = HNullify $ htabulate $ \field -> case hfield hspecs field of
77+ case hfield hspecs field of
67− SSpec {} -> case hfield (hdicts @_ @(NullifySpecC c)) field of
78+ Spec {nullity} -> case hfield as (HMapTableField field) of
68− Dict -> NullifySpec Dict
79+ a -> case nullity of
69−
80+ Null -> guarder a
70− hspecs = HNullify $ htabulate $ \field -> case hfield hspecs field of
81+ NotNull -> guarder a
71− SSpec {..} -> case nullability of
72− Nullable -> NullifySpec SSpec {nullability = Nullable, ..}
73− NonNullable -> NullifySpec SSpec {nullability = Nullable, ..}
74−
75− {-# INLINABLE hfield #-}
76− {-# INLINABLE htabulate #-}
77− {-# INLINABLE htraverse #-}
78− {-# INLINABLE hdicts #-}
79− {-# INLINABLE hspecs #-}
80−
81−
82−type NullifyingSpec :: Type -> Type
83−type NullifyingSpec r = (Spec -> r) -> Spec -> r
84−
85−
86−type NullifySpec :: NullifyingSpec Type
87−data NullifySpec context spec where
88− NullifySpec
89− :: { getNullifySpec :: context ('Spec labels necessity dbType (Maybe dbType)) }
90− -> NullifySpec context ('Spec labels necessity dbType a)
91−
92−
93−type NullifySpecC :: NullifyingSpec Constraint
94−class
95− ( forall labels necessity dbType a.
96− ( spec ~ 'Spec labels necessity dbType a =>
97− constraint ('Spec labels necessity dbType (Maybe dbType))
98− )
99− ) => NullifySpecC constraint spec
100−instance
101− ( spec ~ 'Spec labels necessity dbType a
102− , constraint ('Spec labels necessity dbType (Maybe dbType))
103− ) => NullifySpecC constraint spec
104−
105−
106−traverseNullifySpec :: forall context context' spec m. Functor m
107− => (forall x. context x -> m (context' x))
108− -> NullifySpec context spec -> m (NullifySpec context' spec)
109−traverseNullifySpec f (NullifySpec a) = NullifySpec <$> f a
110
82
111
83
112hnulls :: HTable t
84hnulls :: HTable t
113− => (forall labels necessity dbType. ()
85+ => (forall a. Spec a -> context (Type.Nullify a))
114− => context ('Spec labels necessity dbType (Maybe dbType)))
115 -> HNullify t context
86 -> HNullify t context
116−hnulls null = HNullify $ htabulate $ \field -> case hfield hspecs field of
87+hnulls null = HNullify $ htabulate $ \(HMapTableField field) ->
117− SSpec {} -> NullifySpec null
88+ case hfield hspecs field of
89+ spec@Spec {} -> null spec
118{-# INLINABLE hnulls #-}
90{-# INLINABLE hnulls #-}
119
91
120
92
121hnullify :: HTable t
93hnullify :: HTable t
122− => (forall labels necessity dbType a. ()
94+ => (forall a. Spec a -> context a -> context (Type.Nullify a))
123− => SSpec ('Spec labels necessity dbType a)
124− -> context ('Spec labels necessity dbType a)
125− -> context ('Spec labels necessity dbType (Maybe dbType)))
126 -> t context
95 -> t context
127 -> HNullify t context
96 -> HNullify t context
128−hnullify nullifier a = HNullify $ htabulate $ \field ->
97+hnullify nullifier a = HNullify $ htabulate $ \(HMapTableField field) ->
129 case hfield hspecs field of
98 case hfield hspecs field of
130− spec@SSpec {} -> NullifySpec (nullifier spec (hfield a field))
99+ spec@Spec {} -> nullifier spec (hfield a field)
131{-# INLINABLE hnullify #-}
100{-# INLINABLE hnullify #-}
132
101
133
102
134hunnullify :: (HTable t, Apply m)
103hunnullify :: (HTable t, Apply m)
135− => (forall labels necessity dbType a. ()
104+ => (forall a. Spec a -> context (Type.Nullify a) -> m (context a))
136− => SSpec ('Spec labels necessity dbType a)
137− -> context ('Spec labels necessity dbType (Maybe dbType))
138− -> m (context ('Spec labels necessity dbType a)))
139 -> HNullify t context
105 -> HNullify t context
140 -> m (t context)
106 -> m (t context)
141hunnullify unnullifier (HNullify as) =
107hunnullify unnullifier (HNullify as) =
142 htabulateA $ \field -> case hfield hspecs field of
108 htabulateA $ \field -> case hfield hspecs field of
143− spec@SSpec {} -> case hfield as field of
109+ spec@Spec {} -> case hfield as (HMapTableField field) of
144− NullifySpec a -> unnullifier spec a
110+ a -> unnullifier spec a
145{-# INLINABLE hunnullify #-}
111{-# INLINABLE hunnullify #-}
112+
113+
114+hproject :: ()
115+ => (forall ctx. t ctx -> t' ctx)
116+ -> HNullify t context -> HNullify t' context
117+hproject f (HNullify a) = HNullify (HMapTable.hproject f a)
src/Rel8/Schema/HTable/Pair.hsdeleted−20
@@ -1,20 +0,0 @@
1−{-# language DataKinds #-}
2−{-# language StandaloneKindSignatures #-}
3−
4−module Rel8.Schema.HTable.Pair
5− ( HPair(..)
6− )
7−where
8−
9−-- base
10−import Prelude ()
11−
12−-- rel8
13−import qualified Rel8.Schema.Kind as K
14−
15−
16−type HPair :: K.HTable -> K.HTable -> K.HTable
17−data HPair fst snd context = HPair
18− { hfst :: fst context
19− , hsnd :: snd context
20− }
src/Rel8/Schema/HTable/Product.hsnew file+17
@@ -0,0 +1,17 @@
1+{-# language DataKinds #-}
2+{-# language StandaloneKindSignatures #-}
3+
4+module Rel8.Schema.HTable.Product
5+ ( HProduct(..)
6+ )
7+where
8+
9+-- base
10+import Prelude ()
11+
12+-- rel8
13+import qualified Rel8.Schema.Kind as K
14+
15+
16+type HProduct :: K.HTable -> K.HTable -> K.HTable
17+data HProduct a b context = HProduct (a context) (b context)
src/Rel8/Schema/HTable/Quartet.hsdeleted−29
@@ -1,29 +0,0 @@
1−{-# language DataKinds #-}
2−{-# language DeriveAnyClass #-}
3−{-# language DeriveGeneric #-}
4−{-# language DerivingStrategies #-}
5−{-# language StandaloneKindSignatures #-}
6−
7−module Rel8.Schema.HTable.Quartet
8− ( HQuartet(..)
9− )
10−where
11−
12−-- base
13−import GHC.Generics ( Generic )
14−import Prelude ()
15−
16−-- rel8
17−import Rel8.Schema.HTable ( HTable )
18−import qualified Rel8.Schema.Kind as K
19−
20−
21−type HQuartet :: K.HTable -> K.HTable -> K.HTable -> K.HTable -> K.HTable
22−data HQuartet w x y z context = HQuartet
23− { hfst :: w context
24− , hsnd :: x context
25− , htrd :: y context
26− , hfrt :: z context
27− }
28− deriving stock Generic
29− deriving anyclass HTable
src/Rel8/Schema/HTable/Quintet.hsdeleted−30
@@ -1,30 +0,0 @@
1−{-# language DataKinds #-}
2−{-# language DeriveAnyClass #-}
3−{-# language DeriveGeneric #-}
4−{-# language DerivingStrategies #-}
5−{-# language StandaloneKindSignatures #-}
6−
7−module Rel8.Schema.HTable.Quintet
8− ( HQuintet(..)
9− )
10−where
11−
12−-- base
13−import GHC.Generics ( Generic )
14−import Prelude ()
15−
16−-- rel8
17−import Rel8.Schema.HTable ( HTable )
18−import qualified Rel8.Schema.Kind as K
19−
20−
21−type HQuintet :: K.HTable -> K.HTable -> K.HTable -> K.HTable -> K.HTable -> K.HTable
22−data HQuintet v w x y z context = HQuintet
23− { hfst :: v context
24− , hsnd :: w context
25− , htrd :: x context
26− , hfrt :: y context
27− , hfft :: z context
28− }
29− deriving stock Generic
30− deriving anyclass HTable
src/Rel8/Schema/HTable/These.hs+5−6
@@ -14,21 +14,20 @@ import GHC.Generics ( Generic )
14import Prelude
14import Prelude
15
15
16-- rel8
16-- rel8
17−import Rel8.Kind.Necessity ( Necessity( Required ) )
18import Rel8.Schema.HTable ( HTable )
17import Rel8.Schema.HTable ( HTable )
19import Rel8.Schema.HTable.Identity ( HIdentity )
18import Rel8.Schema.HTable.Identity ( HIdentity )
19+import Rel8.Schema.HTable.Label ( HLabel )
20import Rel8.Schema.HTable.Nullify ( HNullify )
20import Rel8.Schema.HTable.Nullify ( HNullify )
21import qualified Rel8.Schema.Kind as K
21import qualified Rel8.Schema.Kind as K
22−import Rel8.Schema.Spec ( Spec( Spec ) )
23import Rel8.Type.Tag ( MaybeTag )
22import Rel8.Type.Tag ( MaybeTag )
24
23
25
24
26type HTheseTable :: K.HTable -> K.HTable -> K.HTable
25type HTheseTable :: K.HTable -> K.HTable -> K.HTable
27data HTheseTable here there context = HTheseTable
26data HTheseTable here there context = HTheseTable
28− { hhereTag :: HIdentity ('Spec '["hasHere"] 'Required MaybeTag (Maybe MaybeTag)) context
27+ { hhereTag :: HLabel "hereTag" (HIdentity (Maybe MaybeTag)) context
29− , hhere :: HNullify here context
28+ , hhere :: HLabel "Here" (HNullify here) context
30− , hthereTag :: HIdentity ('Spec '["hasThere"] 'Required MaybeTag (Maybe MaybeTag)) context
29+ , hthereTag :: HLabel "thereTag" (HIdentity (Maybe MaybeTag)) context
31− , hthere :: HNullify there context
30+ , hthere :: HLabel "There" (HNullify there) context
32 }
31 }
33 deriving stock Generic
32 deriving stock Generic
34 deriving anyclass HTable
33 deriving anyclass HTable
src/Rel8/Schema/HTable/Trio.hsdeleted−28
@@ -1,28 +0,0 @@
1−{-# language DataKinds #-}
2−{-# language DeriveAnyClass #-}
3−{-# language DeriveGeneric #-}
4−{-# language DerivingStrategies #-}
5−{-# language StandaloneKindSignatures #-}
6−
7−module Rel8.Schema.HTable.Trio
8− ( HTrio(..)
9− )
10−where
11−
12−-- base
13−import GHC.Generics ( Generic )
14−import Prelude ()
15−
16−-- rel8
17−import Rel8.Schema.HTable ( HTable )
18−import qualified Rel8.Schema.Kind as K
19−
20−
21−type HTrio :: K.HTable -> K.HTable -> K.HTable -> K.HTable
22−data HTrio x y z context = HTrio
23− { hfst :: x context
24− , hsnd :: y context
25− , htrd :: z context
26− }
27− deriving stock Generic
28− deriving anyclass HTable
src/Rel8/Schema/HTable/Type.hsdeleted−55
@@ -1,55 +0,0 @@
1−{-# language DataKinds #-}
2−{-# language GADTs #-}
3−{-# language StandaloneKindSignatures #-}
4−{-# language TypeFamilies #-}
5−{-# language UndecidableInstances #-}
6−
7−module Rel8.Schema.HTable.Type
8− ( HType(..)
9− )
10−where
11−
12−-- base
13−import Data.Kind ( Type )
14−import Data.Proxy ( Proxy( Proxy ) )
15−import Prelude
16−
17−-- rel8
18−import Rel8.Kind.Labels ( SLabels( SLabel ) )
19−import Rel8.Kind.Necessity ( Necessity( Required ), SNecessity( SRequired ) )
20−import Rel8.Schema.Dict ( Dict( Dict ) )
21−import Rel8.Schema.HTable
22− ( HTable, HConstrainTable, HField
23− , hfield, htabulate, htraverse, hdicts, hspecs
24− )
25−import qualified Rel8.Schema.Kind as K
26−import Rel8.Schema.Nullability ( Unnullify, Sql, nullabilization )
27−import Rel8.Schema.Spec ( Spec( Spec ), SSpec(..) )
28−import Rel8.Type ( DBType, typeInformation )
29−
30−
31−type HType :: Type -> K.HTable
32−newtype HType a context = HType
33− { unHType :: context ('Spec '[""] 'Required (Unnullify a) a)
34− }
35−
36−
37−type HTypeField :: Type -> Spec -> Type
38−data HTypeField a spec where
39− HTypeField :: HTypeField a ('Spec '[""] 'Required (Unnullify a) a)
40−
41−
42−instance Sql DBType a => HTable (HType a) where
43− type HConstrainTable (HType a) c = c ('Spec '[""] 'Required (Unnullify a) a)
44− type HField (HType a) = HTypeField a
45−
46− hfield (HType a) HTypeField = a
47− htabulate f = HType $ f HTypeField
48− htraverse f (HType a) = HType <$> f a
49− hdicts = HType Dict
50− hspecs = HType SSpec
51− { labels = SLabel Proxy
52− , necessity = SRequired
53− , info = typeInformation
54− , nullability = nullabilization
55− }
src/Rel8/Schema/HTable/Vectorize.hs+64−134
@@ -1,213 +1,143 @@
1{-# language AllowAmbiguousTypes #-}
1{-# language AllowAmbiguousTypes #-}
2{-# language ConstraintKinds #-}
2{-# language ConstraintKinds #-}
3{-# language DataKinds #-}
3{-# language DataKinds #-}
4+{-# language DeriveAnyClass #-}
5+{-# language DeriveGeneric #-}
6+{-# language DerivingStrategies #-}
4{-# language FlexibleContexts #-}
7{-# language FlexibleContexts #-}
5{-# language FlexibleInstances #-}
8{-# language FlexibleInstances #-}
6{-# language GADTs #-}
9{-# language GADTs #-}
7−{-# language InstanceSigs #-}
10+{-# language LambdaCase #-}
8{-# language MultiParamTypeClasses #-}
11{-# language MultiParamTypeClasses #-}
9−{-# language NamedFieldPuns #-}
10−{-# language QuantifiedConstraints #-}
11{-# language RankNTypes #-}
12{-# language RankNTypes #-}
12{-# language RecordWildCards #-}
13{-# language RecordWildCards #-}
13{-# language ScopedTypeVariables #-}
14{-# language ScopedTypeVariables #-}
14{-# language StandaloneKindSignatures #-}
15{-# language StandaloneKindSignatures #-}
15{-# language TypeApplications #-}
16{-# language TypeApplications #-}
16{-# language TypeFamilies #-}
17{-# language TypeFamilies #-}
17−{-# language TypeOperators #-}
18{-# language UndecidableInstances #-}
18{-# language UndecidableInstances #-}
19
19
20module Rel8.Schema.HTable.Vectorize
20module Rel8.Schema.HTable.Vectorize
21− ( HVectorize( HVectorize )
21+ ( HVectorize
22 , hvectorize, hunvectorize
22 , hvectorize, hunvectorize
23 , happend, hempty
23 , happend, hempty
24− , hrelabel
24+ , hproject
25+ , hcolumn
25 )
26 )
26where
27where
27
28
28-- base
29-- base
29import Data.Kind ( Constraint, Type )
30import Data.Kind ( Constraint, Type )
30import Data.List.NonEmpty ( NonEmpty )
31import Data.List.NonEmpty ( NonEmpty )
31−import Data.Type.Equality ( (:~:)( Refl ) )
32+import GHC.Generics (Generic)
32import Prelude
33import Prelude
33
34
34-- rel8
35-- rel8
35−import Rel8.Schema.Context.Label ( HLabelable, hlabeler, hunlabeler )
36+import Rel8.FCF ( Eval, Exp )
36import Rel8.Schema.Dict ( Dict( Dict ) )
37import Rel8.Schema.Dict ( Dict( Dict ) )
37import qualified Rel8.Schema.Kind as K
38import qualified Rel8.Schema.Kind as K
38−import Rel8.Schema.HTable
39− ( HTable, HConstrainTable, HField
40− , hfield, htabulate, htabulateA, htraverse, hdicts, hspecs
39+import Rel8.Schema.HTable ( HTable, hfield, htabulate, htabulateA, hspecs )
40+import Rel8.Schema.HTable.Identity ( HIdentity( HIdentity ) )
41+import Rel8.Schema.HTable.MapTable
42+ ( HMapTable( HMapTable ), HMapTableField( HMapTableField )
43+ , MapSpec, mapInfo
44+ , Precompose( Precompose )
41 )
45 )
42−import Rel8.Schema.Nullability ( IsMaybe, Nullability( NonNullable ) )
46+import qualified Rel8.Schema.HTable.MapTable as HMapTable ( hproject )
47+import Rel8.Schema.Null ( Unnullify, NotNull, Nullity( NotNull ) )
43−import Rel8.Schema.Spec ( Spec( Spec ), SSpec(..) )
48+import Rel8.Schema.Spec ( Spec(..) )
44import Rel8.Type.Array ( listTypeInformation, nonEmptyTypeInformation )
49import Rel8.Type.Array ( listTypeInformation, nonEmptyTypeInformation )
45import Rel8.Type.Information ( TypeInformation )
50import Rel8.Type.Information ( TypeInformation )
46
51
47-- semialign
52-- semialign
48−import Data.Zip ( Unzip, Repeat, Zippy(..) )
53+import Data.Zip ( Unzip, Zip, Zippy(..) )
49
54
50
55
56+type Vector :: (Type -> Type) -> Constraint
51class Vector list where
57class Vector list where
52− listIsn'tMaybe :: proxy a -> IsMaybe (list a) :~: 'False
58+ listNotNull :: proxy a -> Dict NotNull (list a)
53 vectorTypeInformation :: ()
59 vectorTypeInformation :: ()
54− => Nullability a ma
60+ => Nullity a
55− -> TypeInformation a
61+ -> TypeInformation (Unnullify a)
56− -> TypeInformation (list ma)
62+ -> TypeInformation (list a)
57
63
58
64
59instance Vector [] where
65instance Vector [] where
60− listIsn'tMaybe _ = Refl
66+ listNotNull _ = Dict
61 vectorTypeInformation = listTypeInformation
67 vectorTypeInformation = listTypeInformation
62
68
63
69
64instance Vector NonEmpty where
70instance Vector NonEmpty where
65− listIsn'tMaybe _ = Refl
71+ listNotNull _ = Dict
66 vectorTypeInformation = nonEmptyTypeInformation
72 vectorTypeInformation = nonEmptyTypeInformation
67
73
68
74
69type HVectorize :: (Type -> Type) -> K.HTable -> K.HTable
75type HVectorize :: (Type -> Type) -> K.HTable -> K.HTable
70−newtype HVectorize list table context =
76+newtype HVectorize list table context = HVectorize (HMapTable (Vectorize list) table context)
71− HVectorize (table (VectorizeSpec list context))
77+ deriving stock Generic
72−
78+ deriving anyclass HTable
73−
74−type HVectorizeField :: (Type -> Type) -> K.HTable -> Spec -> Type
75−data HVectorizeField list table spec where
76− HVectorizeField
77− :: HField table ('Spec labels necessity db a)
78− -> HVectorizeField list table
79− ('Spec labels necessity (list a) (list a)
80− )
81−
82−
83−instance (HTable table, Vector list) => HTable (HVectorize list table) where
84− type HField (HVectorize list table) = HVectorizeField list table
85− type HConstrainTable (HVectorize list table) c =
86− HConstrainTable table (VectorizeSpecC list c)
87−
88− hfield (HVectorize table) (HVectorizeField field) =
89− getVectorizeSpec (hfield table field)
90−
91− htabulate f = HVectorize $ htabulate $ \field -> case hfield hspecs field of
92− SSpec {} -> VectorizeSpec (f (HVectorizeField field))
93− htraverse f (HVectorize t) = HVectorize <$> htraverse (traverseVectorizeSpec f) t
94−
95− hdicts :: forall c. HConstrainTable table (VectorizeSpecC list c) =>
96− HVectorize list table (Dict c)
97− hdicts = HVectorize $ htabulate $ \field -> case hfield hspecs field of
98− SSpec {} -> case hfield (hdicts @_ @(VectorizeSpecC list c)) field of
99− Dict -> VectorizeSpec Dict
100−
101− hspecs = HVectorize $ htabulate $ \field -> case hfield hspecs field of
102− SSpec {..} -> case listIsn'tMaybe @list nullability of
103− Refl -> VectorizeSpec SSpec
104− { nullability = NonNullable
105− , info = vectorTypeInformation nullability info
106− , ..
107− }
108−
109− {-# INLINABLE hfield #-}
110− {-# INLINABLE htabulate #-}
111− {-# INLINABLE htraverse #-}
112− {-# INLINABLE hdicts #-}
113− {-# INLINABLE hspecs #-}
114−
115
79
116−type VectorizingSpec :: Type -> Type
117−type VectorizingSpec r = (Type -> Type) -> (Spec -> r) -> Spec -> r
118
80
81+data Vectorize :: (Type -> Type) -> Type -> Exp Type
119
82
120−type VectorizeSpec :: VectorizingSpec Type
121−data VectorizeSpec list context spec where
122− VectorizeSpec ::
123− { getVectorizeSpec :: context ('Spec labels necessity (list a) (list a))
124− } -> VectorizeSpec list context ('Spec labels necessity db a)
125
83
126−
84+type instance Eval (Vectorize list a) = list a
127−instance HLabelable context => HLabelable (VectorizeSpec list context) where
128− hlabeler (VectorizeSpec a) = VectorizeSpec (hlabeler a)
129− hunlabeler (VectorizeSpec a) = VectorizeSpec (hunlabeler a)
130−
131−
132−type VectorizeSpecC :: VectorizingSpec Constraint
133−class
134− ( forall labels necessity db a.
135− ( spec ~ 'Spec labels necessity db a
136− => constraint ('Spec labels necessity (list a) (list a))
137− )
138− )
139− => VectorizeSpecC list constraint spec
140−instance
141− ( spec ~ 'Spec labels necessity db a
142− , constraint ('Spec labels necessity (list a) (list a))
143− )
144− => VectorizeSpecC list constraint spec
145
85
146
86
147−traverseVectorizeSpec :: forall context context' list spec m. Functor m
87+instance Vector list => MapSpec (Vectorize list) where
148− => (forall x. context x -> m (context' x))
88+ mapInfo = \case
149− -> VectorizeSpec list context spec
89+ Spec {..} -> case listNotNull @list nullity of
150− -> m (VectorizeSpec list context' spec)
90+ Dict -> Spec
151−traverseVectorizeSpec f (VectorizeSpec a) = VectorizeSpec <$> f a
91+ { nullity = NotNull
92+ , info = vectorTypeInformation nullity info
93+ , ..
94+ }
152
95
153
96
154−hvectorize :: (HTable t, Unzip f)
97+hvectorize :: (HTable t, Unzip f, Vector list)
155− => (forall labels necessity db a. ()
98+ => (forall a. Spec a -> f (context a) -> context' (list a))
156− => SSpec ('Spec labels necessity db a)
157− -> f (context ('Spec labels necessity db a))
158− -> context' ('Spec labels necessity (list a) (list a)))
159 -> f (t context)
99 -> f (t context)
160 -> HVectorize list t context'
100 -> HVectorize list t context'
161−hvectorize vectorizer as = HVectorize $ htabulate $ \field ->
101+hvectorize vectorizer as = HVectorize $ htabulate $ \(HMapTableField field) ->
162 case hfield hspecs field of
102 case hfield hspecs field of
163− spec@SSpec {} -> VectorizeSpec (vectorizer spec (fmap (`hfield` field) as))
103+ spec -> vectorizer spec (fmap (`hfield` field) as)
164{-# INLINABLE hvectorize #-}
104{-# INLINABLE hvectorize #-}
165
105
166
106
167−hunvectorize :: (HTable t, Repeat f)
107+hunvectorize :: (HTable t, Zip f, Vector list)
168− => (forall labels necessity db a. ()
108+ => (forall a. Spec a -> context (list a) -> f (context' a))
169− => SSpec ('Spec labels necessity db a)
170− -> context ('Spec labels necessity (list a) (list a))
171− -> f (context' ('Spec labels necessity db a)))
172 -> HVectorize list t context
109 -> HVectorize list t context
173 -> f (t context')
110 -> f (t context')
174hunvectorize unvectorizer (HVectorize table) =
111hunvectorize unvectorizer (HVectorize table) =
175 getZippy $ htabulateA $ \field -> case hfield hspecs field of
112 getZippy $ htabulateA $ \field -> case hfield hspecs field of
176− spec -> case hfield table field of
113+ spec -> case hfield table (HMapTableField field) of
177− VectorizeSpec a -> Zippy (unvectorizer spec a)
114+ a -> Zippy (unvectorizer spec a)
178{-# INLINABLE hunvectorize #-}
115{-# INLINABLE hunvectorize #-}
179
116
180
117
181−happend :: HTable t =>
118+happend :: (HTable t, Vector list)
182− ( forall labels necessity db a. ()
119+ => (forall a. Spec a -> context (list a) -> context (list a) -> context (list a))
183− => Nullability db a
184− -> TypeInformation db
185− -> context ('Spec labels necessity (list a) (list a))
186− -> context ('Spec labels necessity (list a) (list a))
187− -> context ('Spec labels necessity (list a) (list a))
188− )
189 -> HVectorize list t context
120 -> HVectorize list t context
190 -> HVectorize list t context
121 -> HVectorize list t context
191 -> HVectorize list t context
122 -> HVectorize list t context
192happend append (HVectorize as) (HVectorize bs) = HVectorize $
123happend append (HVectorize as) (HVectorize bs) = HVectorize $
193− htabulate $ \field -> case (hfield as field, hfield bs field) of
124+ htabulate $ \field@(HMapTableField j) -> case (hfield as field, hfield bs field) of
194− (VectorizeSpec a, VectorizeSpec b) -> case hfield hspecs field of
125+ (a, b) -> case hfield hspecs j of
195− SSpec {nullability, info} -> VectorizeSpec $ append nullability info a b
126+ spec -> append spec a b
196
127
197
128
198−hempty :: HTable t =>
129+hempty :: HTable t
199− ( forall labels necessity db a. ()
130+ => (forall a. Spec a -> context [a])
200− => Nullability db a
201− -> TypeInformation db
202− -> context ('Spec labels necessity [a] [a])
203− )
204 -> HVectorize [] t context
131 -> HVectorize [] t context
205−hempty empty = HVectorize $ htabulate $ \field -> case hfield hspecs field of
132+hempty empty = HVectorize $ htabulate $ \(HMapTableField field) ->
206− SSpec {nullability, info} -> VectorizeSpec (empty nullability info)
133+ empty (hfield hspecs field)
207
134
208
135
209−hrelabel :: HLabelable context
136+hproject :: ()
210− => (forall ctx. HLabelable ctx => t ctx -> u ctx)
137+ => (forall ctx. t ctx -> t' ctx)
211− -> HVectorize list t context
138+ -> HVectorize list t context -> HVectorize list t' context
212− -> HVectorize list u context
213−hrelabel f (HVectorize table) = HVectorize (f table)
139+hproject f (HVectorize a) = HVectorize (HMapTable.hproject f a)
140+
141+
142+hcolumn :: HVectorize list (HIdentity a) context -> context (list a)
143+hcolumn (HVectorize (HMapTable (HIdentity (Precompose a)))) = a
src/Rel8/Schema/Kind.hs+8−14
@@ -1,8 +1,9 @@
1{-# language StandaloneKindSignatures #-}
1{-# language StandaloneKindSignatures #-}
2
2
3module Rel8.Schema.Kind
3module Rel8.Schema.Kind
4+ ( Rel8able
4− ( Context, Table
5+ , Context
5− , HContext, HTable
6+ , HTable
6 )
7 )
7where
8where
8
9
@@ -10,21 +11,14 @@ where
10import Data.Kind ( Type )
11import Data.Kind ( Type )
11import Prelude ()
12import Prelude ()
12
13
13−-- rel8
14−import Rel8.Schema.Spec ( Spec )
15
14
16−
17−type HContext :: Type
15+type Context :: Type
18−type HContext = Spec -> Type
16+type Context = Type -> Type
19
17
20
18
21type HTable :: Type
19type HTable :: Type
22−type HTable = HContext -> Type
23−
24−
25−type Context :: Type
26−type Context = Type -> Type
20+type HTable = Context -> Type
27
21
28
22
29−type Table :: Type
23+type Rel8able :: Type
30−type Table = Context -> Type
24+type Rel8able = Context -> Type
src/Rel8/Schema/Name.hsnew file+77
@@ -0,0 +1,77 @@
1+{-# language DataKinds #-}
2+{-# language DerivingStrategies #-}
3+{-# language FlexibleContexts #-}
4+{-# language FlexibleInstances #-}
5+{-# language GADTs #-}
6+{-# language GeneralizedNewtypeDeriving #-}
7+{-# language MultiParamTypeClasses #-}
8+{-# language RankNTypes #-}
9+{-# language StandaloneKindSignatures #-}
10+{-# language TypeFamilies #-}
11+{-# language UndecidableInstances #-}
12+
13+module Rel8.Schema.Name
14+ ( Name(..)
15+ , Selects
16+ , ppColumn
17+ )
18+where
19+
20+-- base
21+import Data.Functor.Identity ( Identity( Identity ) )
22+import Data.Kind ( Constraint, Type )
23+import Data.String ( IsString )
24+import Prelude
25+
26+-- opaleye
27+import qualified Opaleye.Internal.HaskellDB.Sql as Opaleye
28+import qualified Opaleye.Internal.HaskellDB.Sql.Print as Opaleye
29+
30+-- pretty
31+import Text.PrettyPrint ( Doc )
32+
33+-- rel8
34+import Rel8.Expr ( Expr )
35+import qualified Rel8.Schema.Kind as K
36+import Rel8.Schema.HTable.Identity ( HIdentity( HIdentity ) )
37+import Rel8.Schema.Null ( Sql )
38+import Rel8.Table
39+ ( Table, Columns, Context, fromColumns, toColumns
40+ , FromExprs, fromResult, toResult
41+ , Transpose
42+ )
43+import Rel8.Table.Transpose ( Transposes )
44+import Rel8.Type ( DBType )
45+
46+
47+-- | A @Name@ is the name of a column, as it would be defined in a table's
48+-- schema definition. You can construct names by using the @OverloadedStrings@
49+-- extension and writing string literals. This is typically done when providing
50+-- a 'TableSchema' value.
51+type Name :: K.Context
52+newtype Name a = Name String
53+ deriving stock Show
54+ deriving newtype IsString
55+
56+
57+instance Sql DBType a => Table Name (Name a) where
58+ type Columns (Name a) = HIdentity a
59+ type Context (Name a) = Name
60+ type FromExprs (Name a) = a
61+ type Transpose to (Name a) = to a
62+
63+ toColumns a = HIdentity a
64+ fromColumns (HIdentity a) = a
65+ toResult a = HIdentity (Identity a)
66+ fromResult (HIdentity (Identity a)) = a
67+
68+
69+-- | @Selects a b@ means that @a@ is a schema (i.e., a 'Table' of 'Name's) for
70+-- the 'Expr' columns in @b@.
71+type Selects :: Type -> Type -> Constraint
72+class Transposes Name Expr names exprs => Selects names exprs
73+instance Transposes Name Expr names exprs => Selects names exprs
74+
75+
76+ppColumn :: String -> Doc
77+ppColumn = Opaleye.ppSqlExpr . Opaleye.ColumnSqlExpr . Opaleye.SqlColumn
src/Rel8/Schema/Null.hsnew file+110
@@ -0,0 +1,110 @@
1+{-# language ConstraintKinds #-}
2+{-# language DataKinds #-}
3+{-# language FlexibleContexts #-}
4+{-# language FlexibleInstances #-}
5+{-# language GADTs #-}
6+{-# language MultiParamTypeClasses #-}
7+{-# language RankNTypes #-}
8+{-# language StandaloneKindSignatures #-}
9+{-# language TypeFamilies #-}
10+{-# language UndecidableInstances #-}
11+{-# language UndecidableSuperClasses #-}
12+
13+module Rel8.Schema.Null
14+ ( Nullify, Unnullify
15+ , NotNull
16+ , Homonullable
17+ , Nullity( Null, NotNull )
18+ , Nullable, nullable
19+ , Sql
20+ )
21+where
22+
23+-- base
24+import Data.Kind ( Constraint, Type )
25+import Prelude
26+
27+
28+type IsMaybe :: Type -> Bool
29+type family IsMaybe a where
30+ IsMaybe (Maybe _) = 'True
31+ IsMaybe _ = 'False
32+
33+
34+type Unnullify' :: Bool -> Type -> Type
35+type family Unnullify' isMaybe ma where
36+ Unnullify' 'False a = a
37+ Unnullify' 'True (Maybe a) = a
38+
39+
40+type Unnullify :: Type -> Type
41+type Unnullify a = Unnullify' (IsMaybe a) a
42+
43+
44+type Nullify' :: Bool -> Type -> Type
45+type family Nullify' isMaybe a where
46+ Nullify' 'False a = a
47+ Nullify' 'True a = Maybe a
48+
49+
50+type Nullify :: Type -> Type
51+type Nullify a = Maybe (Unnullify a)
52+
53+
54+-- | @nullify a@ means @a@ cannot take @null@ as a value.
55+type NotNull :: Type -> Constraint
56+class (Nullable a, IsMaybe a ~ 'False) => NotNull a
57+instance (Nullable a, IsMaybe a ~ 'False) => NotNull a
58+
59+
60+-- | @Homonullable a b@ means that both @a@ and @b@ can be @null@, or neither
61+-- @a@ or @b@ can be @null@.
62+type Homonullable :: Type -> Type -> Constraint
63+class IsMaybe a ~ IsMaybe b => Homonullable a b
64+instance IsMaybe a ~ IsMaybe b => Homonullable a b
65+
66+
67+type Nullity :: Type -> Type
68+data Nullity a where
69+ NotNull :: NotNull a => Nullity a
70+ Null :: NotNull a => Nullity (Maybe a)
71+
72+
73+type Nullable' :: Bool -> Type -> Constraint
74+class
75+ ( IsMaybe a ~ isMaybe
76+ , IsMaybe (Unnullify a) ~ 'False
77+ , Nullify' isMaybe (Unnullify a) ~ a
78+ ) => Nullable' isMaybe a
79+ where
80+ nullable' :: Nullity a
81+
82+
83+instance IsMaybe a ~ 'False => Nullable' 'False a where
84+ nullable' = NotNull
85+
86+
87+instance IsMaybe a ~ 'False => Nullable' 'True (Maybe a) where
88+ nullable' = Null
89+
90+
91+-- | @Nullable a@ means that @rel8@ is able to check if the type @a@ is a
92+-- type that can take @null@ values or not.
93+type Nullable :: Type -> Constraint
94+class Nullable' (IsMaybe a) a => Nullable a
95+instance Nullable' (IsMaybe a) a => Nullable a
96+
97+
98+nullable :: Nullable a => Nullity a
99+nullable = nullable'
100+
101+
102+-- | The @Sql@ type class describes both null and not null database values,
103+-- constrained by a specific class.
104+--
105+-- For example, if you see @Sql DBEq a@, this means any database type that
106+-- supports equality, and @a@ can either be exactly an @a@, or it could also be
107+-- @Maybe a@.
108+type Sql :: (Type -> Constraint) -> Type -> Constraint
109+class (constraint (Unnullify a), Nullable a) => Sql constraint a
110+instance (constraint (Unnullify a), Nullable a) => Sql constraint a
src/Rel8/Schema/Nullability.hsdeleted−106
@@ -1,106 +0,0 @@
1−{-# language ConstraintKinds #-}
2−{-# language DataKinds #-}
3−{-# language FlexibleContexts #-}
4−{-# language FlexibleInstances #-}
5−{-# language FunctionalDependencies #-}
6−{-# language GADTs #-}
7−{-# language MultiParamTypeClasses #-}
8−{-# language QuantifiedConstraints #-}
9−{-# language StandaloneKindSignatures #-}
10−{-# language TypeFamilies #-}
11−{-# language UndecidableInstances #-}
12−{-# language UndecidableSuperClasses #-}
13−
14−module Rel8.Schema.Nullability
15− ( IsMaybe, Nullify, Unnullify
16− , Nullability( Nullable, NonNullable )
17− , Sql
18− , Nullabilizes, nullabilization
19− )
20−where
21−
22−-- base
23−import Data.Kind ( Constraint, Type )
24−import Prelude
25−
26−-- rel8
27−import Rel8.Opaque ( Opaque )
28−
29−
30−type IsMaybe :: Type -> Bool
31−type family IsMaybe a where
32− IsMaybe (Maybe _) = 'True
33− IsMaybe _ = 'False
34−
35−
36−type Unnullify' :: Bool -> Type -> Type
37−type family Unnullify' isMaybe ma where
38− Unnullify' 'False a = a
39− Unnullify' 'True (Maybe a) = a
40−
41−
42−type Unnullify :: Type -> Type
43−type Unnullify a = Unnullify' (IsMaybe a) a
44−
45−
46−type Nullify' :: Bool -> Type -> Type
47−type family Nullify' isMaybe a where
48− Nullify' 'False a = a
49− Nullify' 'True a = Maybe a
50−
51−
52−type Nullify :: Type -> Type
53−type Nullify a = Maybe (Unnullify a)
54−
55−
56−type Nullability :: Type -> Type -> Type
57−data Nullability a ma where
58− NonNullable :: IsMaybe a ~ 'False => Nullability a a
59− Nullable :: IsMaybe a ~ 'False => Nullability a (Maybe a)
60−
61−
62−type Nullabilizes' :: Bool -> Type -> Type -> Constraint
63−class
64− ( IsMaybe ma ~ isMaybe
65− , IsMaybe a ~ 'False
66− , Unnullify ma ~ a
67− , Nullify' isMaybe a ~ ma
68− ) => Nullabilizes' isMaybe a ma | isMaybe ma -> a, isMaybe a -> ma
69− where
70− nullabilization' :: Nullability a ma
71−
72−
73−instance IsMaybe a ~ 'False => Nullabilizes' 'False a a where
74− nullabilization' = NonNullable
75−
76−
77−instance IsMaybe a ~ 'False => Nullabilizes' 'True a (Maybe a) where
78− nullabilization' = Nullable
79−
80−
81−type Nullabilizes :: Type -> Type -> Constraint
82−class Nullabilizes' (IsMaybe ma) a ma => Nullabilizes a ma
83−instance Nullabilizes' (IsMaybe ma) a ma => Nullabilizes a ma
84−instance {-# OVERLAPPING #-} Nullabilizes Opaque Opaque
85−
86−
87−-- | The @Sql@ type class describes both null and not null database values,
88−-- constrained by a specific class.
89−--
90−-- For example, if you see @Sql DBEq a@, this means any database type that
91−-- supports equality, and @a@ can either be exactly an @a@, or it could also be
92−-- @Maybe a@.
93−type Sql :: (Type -> Constraint) -> Type -> Constraint
94−class
95− ( (forall c. (forall x. (constraint x => c x)) => Sql c a)
96− , Nullabilizes (Unnullify a) a
97− , constraint (Unnullify a)
98− )
99− => Sql constraint a
100−instance (constraint db, Nullabilizes db a) => Sql constraint a
101−instance {-# OVERLAPPING #-} (constraint Opaque, Sql constraint Opaque) => Sql constraint Opaque
102−-- instance {-# OVERLAPPING #-} Sql OpaqueC Opaque => Sql OpaqueC Opaque
103−
104−
105−nullabilization :: forall a db. Nullabilizes db a => Nullability db a
106−nullabilization = nullabilization'
src/Rel8/Schema/Result.hsnew file+54
@@ -0,0 +1,54 @@
1+{-# language DataKinds #-}
2+{-# language GADTs #-}
3+{-# language NamedFieldPuns #-}
4+{-# language StandaloneKindSignatures #-}
5+{-# language TypeFamilies #-}
6+
7+module Rel8.Schema.Result
8+ ( Result
9+ , null, nullifier, unnullifier
10+ , vectorizer, unvectorizer
11+ )
12+where
13+
14+-- base
15+import Data.Functor.Identity ( Identity( Identity), runIdentity )
16+import Prelude hiding ( null )
17+
18+-- rel8
19+import Rel8.Schema.Kind ( Context )
20+import Rel8.Schema.Null ( Nullify, Nullity( Null, NotNull ) )
21+import Rel8.Schema.Spec ( Spec(..) )
22+
23+
24+-- | The @Result@ context is the context used for decoded query results.
25+--
26+-- When a query is executed against a PostgreSQL database, Rel8 parses the
27+-- returned rows, decoding each row into the @Result@ context.
28+type Result :: Context
29+type Result = Identity
30+
31+
32+null :: Result (Maybe a)
33+null = Identity Nothing
34+
35+
36+nullifier :: Spec a -> Result a -> Result (Nullify a)
37+nullifier Spec {nullity} (Identity a) = Identity $ case nullity of
38+ Null -> a
39+ NotNull -> Just a
40+
41+
42+unnullifier :: Spec a -> Result (Nullify a) -> Maybe (Result a)
43+unnullifier Spec {nullity} (Identity a) =
44+ case nullity of
45+ Null -> pure $ Identity a
46+ NotNull -> Identity <$> a
47+
48+
49+vectorizer :: Functor f => Spec a -> f (Result a) -> Result (f a)
50+vectorizer _ = Identity . fmap runIdentity
51+
52+
53+unvectorizer :: Functor f => Spec a -> Result (f a) -> f (Result a)
54+unvectorizer _ (Identity results) = Identity <$> results
src/Rel8/Schema/Spec.hs+18−61
@@ -1,77 +1,34 @@
1−{-# language DataKinds #-}
2{-# language FlexibleContexts #-}
1{-# language FlexibleContexts #-}
3−{-# language GADTs #-}
2+{-# language MonoLocalBinds #-}
4{-# language StandaloneKindSignatures #-}
3{-# language StandaloneKindSignatures #-}
5−{-# language UndecidableInstances #-}
6
4
7module Rel8.Schema.Spec
5module Rel8.Schema.Spec
8− ( Spec( Spec )
6+ ( Spec( Spec, labels, info, nullity )
9− , SSpec( SSpec, labels, necessity, info, nullability )
7+ , specification
10− , KnownSpec( specSing )
11− , KContext, HKTable
12− , KTable
13 )
8 )
14where
9where
15
10
16-- base
11-- base
17−import Data.Kind ( Constraint, Type )
12+import Data.Kind ( Type )
18−import Prelude ()
13+import Prelude
19
14
20-- rel8
15-- rel8
21−import Rel8.Kind.Labels ( Labels, SLabels, KnownLabels, labelsSing )
16+import Rel8.Schema.Null ( Nullity, Sql, Unnullify, nullable )
22−import Rel8.Kind.Necessity
23− ( Necessity
24− , SNecessity
25− , KnownNecessity, necessitySing
26− )
27−import Rel8.Schema.Nullability ( Unnullify, Nullability, Sql, nullabilization )
28import Rel8.Type ( DBType, typeInformation )
17import Rel8.Type ( DBType, typeInformation )
29import Rel8.Type.Information ( TypeInformation )
18import Rel8.Type.Information ( TypeInformation )
30
19
31
20
32−type Spec :: Type
21+type Spec :: Type -> Type
33−data Spec = Spec Labels Necessity Type Type
22+data Spec a = Spec
34−
23+ { labels :: [String]
35−
36−type SSpec :: Spec -> Type
37−data SSpec spec where
38− SSpec ::
39− { labels :: SLabels labels
40− , necessity :: SNecessity necessity
41− , info :: TypeInformation db
24+ , info :: TypeInformation (Unnullify a)
42− , nullability :: Nullability db a
25+ , nullity :: Nullity a
43− }
44− -> SSpec ('Spec labels necessity db a)
45−
46−
47−type KnownSpec :: Spec -> Constraint
48−class KnownSpec spec where
49− specSing :: SSpec spec
50−
51−
52−instance
53− ( KnownLabels labels
54− , KnownNecessity necessity
55− , Sql DBType a
56− , db ~ Unnullify a
57− )
58− => KnownSpec ('Spec labels necessity db a)
59− where
60− specSing = SSpec
61− { labels = labelsSing
62− , necessity = necessitySing
63− , info = typeInformation
64− , nullability = nullabilization
65− }
26+ }
66−
67−
68−type KContext :: Type
69−type KContext = Spec -> Type
70−
71−
72−type HKTable :: Type
73−type HKTable = KContext -> Type
74
27
75
28
76−type KTable :: Type
29+specification :: Sql DBType a => Spec a
77−type KTable = (Type -> Type) -> Type
30+specification = Spec
31+ { labels = []
32+ , info = typeInformation
33+ , nullity = nullable
34+ }
src/Rel8/Schema/Spec/ConstrainDBType.hsdeleted−34
@@ -1,34 +0,0 @@
1−{-# language ConstraintKinds #-}
2−{-# language DataKinds #-}
3−{-# language FlexibleInstances #-}
4−{-# language MultiParamTypeClasses #-}
5−{-# language QuantifiedConstraints #-}
6−{-# language StandaloneKindSignatures #-}
7−{-# language TypeFamilies #-}
8−{-# language UndecidableInstances #-}
9−
10−module Rel8.Schema.Spec.ConstrainDBType
11− ( ConstrainDBType
12− )
13−where
14−
15−-- base
16−import Data.Kind ( Constraint, Type )
17−import Prelude ()
18−
19−-- rel8
20−import Rel8.Schema.Spec ( Spec( Spec ) )
21−
22−
23−type ConstrainDBType :: (Type -> Constraint) -> Spec -> Constraint
24−class
25− ( forall labels necessity db a. ()
26− => (spec ~ 'Spec labels necessity db a)
27− => constraint db
28− )
29− => ConstrainDBType constraint spec
30−instance
31− ( spec ~ 'Spec labels necessity db a
32− , constraint db
33− )
34− => ConstrainDBType constraint spec
src/Rel8/Schema/Spec/ConstrainType.hsdeleted−31
@@ -1,31 +0,0 @@
1−{-# language ConstraintKinds #-}
2−{-# language DataKinds #-}
3−{-# language FlexibleInstances #-}
4−{-# language MultiParamTypeClasses #-}
5−{-# language QuantifiedConstraints #-}
6−{-# language StandaloneKindSignatures #-}
7−{-# language TypeFamilies #-}
8−{-# language UndecidableInstances #-}
9−
10−module Rel8.Schema.Spec.ConstrainType
11− ( ConstrainType
12− )
13−where
14−
15−-- base
16−import Data.Kind ( Constraint, Type )
17−import Prelude ()
18−
19−-- rel8
20−import Rel8.Schema.Spec ( Spec( Spec ) )
21−
22−
23−type ConstrainType :: (Type -> Constraint) -> Spec -> Constraint
24−class
25− ( forall labels necessity db a. ()
26− => (spec ~ 'Spec labels necessity db a)
27− => constraint a
28− ) =>
29− ConstrainType constraint spec
30−instance (spec ~ 'Spec labels necessity db a, constraint a) =>
31− ConstrainType constraint spec
src/Rel8/Schema/Structure.hsdeleted−54
@@ -1,54 +0,0 @@
1−{-# language DataKinds #-}
2−{-# language StandaloneKindSignatures #-}
3−{-# language PolyKinds #-}
4−{-# language TypeFamilies #-}
5−
6−module Rel8.Schema.Structure
7− ( Structure
8− , Shape( Column, Either, List, Maybe, NonEmpty, These )
9− , Shape1
10− , Shape2
11− , IsStructure
12− )
13−where
14−
15−-- base
16−import Data.Kind ( Type )
17−import Prelude
18−
19−-- rel8
20−import qualified Rel8.Schema.Kind as K
21−import Rel8.Schema.Spec ( Spec )
22−
23−
24−type Structure :: K.Context
25−data Structure a
26−
27−
28−type Shape :: Type
29−data Shape
30− = Column Spec
31− | Either Type Type
32− | List Type
33− | Maybe Type
34− | NonEmpty Type
35− | These Type Type
36−
37−
38−type Shape1 :: (a -> Shape) -> a -> Type
39−data Shape1 shape a
40−
41−
42−type Shape2 :: (a -> b -> Shape) -> a -> b -> Type
43−data Shape2 shape a b
44−
45−
46−type IsStructure :: Type -> Bool
47−type family IsStructure a where
48− IsStructure (Shape1 _ _) = 'True
49− IsStructure (Shape2 _ _ _) = 'True
50− IsStructure (_, _) = 'True
51− IsStructure (_, _, _) = 'True
52− IsStructure (_, _, _, _) = 'True
53− IsStructure (_, _, _, _, _) = 'True
54− IsStructure _ = 'False
src/Rel8/Schema/Table.hs+21−14
@@ -1,34 +1,34 @@
1{-# language DeriveFunctor #-}
1{-# language DeriveFunctor #-}
2{-# language DerivingStrategies #-}
2{-# language DerivingStrategies #-}
3+{-# language DisambiguateRecordFields #-}
4+{-# language NamedFieldPuns #-}
5+{-# language StandaloneKindSignatures #-}
3
6
4module Rel8.Schema.Table
7module Rel8.Schema.Table
5 ( TableSchema(..)
8 ( TableSchema(..)
9+ , ppTable
6 )
10 )
7where
11where
8
12
9-- base
13-- base
14+import Data.Kind ( Type )
10import Prelude
15import Prelude
11
16
17+-- opaleye
18+import qualified Opaleye.Internal.HaskellDB.Sql as Opaleye
19+import qualified Opaleye.Internal.HaskellDB.Sql.Print as Opaleye
20+
21+-- pretty
22+import Text.PrettyPrint ( Doc )
23+
12
24
13-- | The schema for a table. This is used to specify the name and schema that a
25-- | The schema for a table. This is used to specify the name and schema that a
14-- table belongs to (the @FROM@ part of a SQL query), along with the schema of
26-- table belongs to (the @FROM@ part of a SQL query), along with the schema of
15-- the columns within this table.
27-- the columns within this table.
16--
28--
17-- For each selectable table in your database, you should provide a
29-- For each selectable table in your database, you should provide a
18−-- @TableSchema@ in order to interact with the table via Rel8. For a table
30+-- @TableSchema@ in order to interact with the table via Rel8.
19−-- storing a list of projects (as defined in the introduction):
31+type TableSchema :: Type -> Type
20−--
21−-- >>> :{
22−-- projectSchema :: TableSchema (Project ColumnSchema)
23−-- projectSchema = TableSchema
24−-- { tableName = "project"
25−-- , tableSchema = Nothing -- Assumes that the 'project' table is reachable from your connection's search_path
26−-- , tableColumns = Project
27−-- { projectAuthorId = "author_id"
28−-- , projectName = "name"
29−-- }
30−-- }
31−-- :}
32data TableSchema names = TableSchema
32data TableSchema names = TableSchema
33 { name :: String
33 { name :: String
34 -- ^ The name of the table.
34 -- ^ The name of the table.
@@ -40,3 +40,10 @@ data TableSchema names = TableSchema
40 -- data type here, parameterized by the 'Rel8.ColumnSchema.ColumnSchema' functor.
40 -- data type here, parameterized by the 'Rel8.ColumnSchema.ColumnSchema' functor.
41 }
41 }
42 deriving stock Functor
42 deriving stock Functor
43+
44+
45+ppTable :: TableSchema a -> Doc
46+ppTable TableSchema {name, schema} = Opaleye.ppTable Opaleye.SqlTable
47+ { sqlTableSchemaName = schema
48+ , sqlTableName = name
49+ }
src/Rel8/Statement/Delete.hs+36−67
@@ -1,40 +1,37 @@
1{-# language DuplicateRecordFields #-}
1{-# language DuplicateRecordFields #-}
2{-# language GADTs #-}
2{-# language GADTs #-}
3{-# language NamedFieldPuns #-}
3{-# language NamedFieldPuns #-}
4−{-# language ScopedTypeVariables #-}
4+{-# language RankNTypes #-}
5+{-# language RecordWildCards #-}
5{-# language StandaloneKindSignatures #-}
6{-# language StandaloneKindSignatures #-}
6−{-# language TypeApplications #-}
7+{-# language StrictData #-}
7
8
8module Rel8.Statement.Delete
9module Rel8.Statement.Delete
9 ( Delete(..)
10 ( Delete(..)
10 , delete
11 , delete
12+ , ppDelete
11 )
13 )
12where
14where
13
15
14-- base
16-- base
15−import Control.Exception ( throwIO )
16import Data.Kind ( Type )
17import Data.Kind ( Type )
17import Prelude
18import Prelude
18
19
19-- hasql
20-- hasql
20−import Hasql.Connection ( Connection )
21−import qualified Hasql.Decoders as Hasql
22import qualified Hasql.Encoders as Hasql
21import qualified Hasql.Encoders as Hasql
23−import qualified Hasql.Session as Hasql
24import qualified Hasql.Statement as Hasql
22import qualified Hasql.Statement as Hasql
25
23
26−-- opaleye
24+-- pretty
27−import qualified Opaleye.Internal.Manipulation as Opaleye
25+import Text.PrettyPrint ( Doc, (<+>), ($$), text )
28
26
29-- rel8
27-- rel8
30import Rel8.Expr ( Expr )
28import Rel8.Expr ( Expr )
31−import Rel8.Expr.Opaleye ( toColumn, toPrimExpr )
29+import Rel8.Query ( Query )
30+import Rel8.Schema.Name ( Selects )
32−import Rel8.Schema.Table ( TableSchema )
31+import Rel8.Schema.Table ( TableSchema, ppTable )
33−import Rel8.Statement.Returning ( Returning( NumberOfRowsAffected, Projection ) )
32+import Rel8.Statement.Returning ( Returning, decodeReturning, ppReturning )
34−import Rel8.Table ( fromColumns, toColumns )
33+import Rel8.Statement.Using ( ppUsing )
35−import Rel8.Table.Opaleye ( table, unpackspec )
34+import Rel8.Statement.Where ( ppWhere )
36−import Rel8.Table.Recontextualize ( Selects )
37−import Rel8.Table.Serialize ( Serializable, parse )
38
35
39-- text
36-- text
40import qualified Data.Text as Text
37import qualified Data.Text as Text
@@ -47,7 +44,10 @@ data Delete a where
47 Delete :: Selects names exprs =>
44 Delete :: Selects names exprs =>
48 { from :: TableSchema names
45 { from :: TableSchema names
49 -- ^ Which table to delete from.
46 -- ^ Which table to delete from.
47+ , using :: Query using
48+ -- ^ @USING@ clause — this can be used to join against other tables,
49+ -- and its results can be referenced in the @WHERE@ clause
50− , deleteWhere :: exprs -> Expr Bool
50+ , deleteWhere :: using -> exprs -> Expr Bool
51 -- ^ Which rows should be selected for deletion.
51 -- ^ Which rows should be selected for deletion.
52 , returning :: Returning names a
52 , returning :: Returning names a
53 -- ^ What to return from the @DELETE@ statement.
53 -- ^ What to return from the @DELETE@ statement.
@@ -55,56 +55,25 @@ data Delete a where
55 -> Delete a
55 -> Delete a
56
56
57
57
58−-- | Run a @DELETE@ statement.
58+ppDelete :: Delete a -> Doc
59−--
59+ppDelete Delete {..} = case ppUsing using of
60−-- >>> mapM_ print =<< select c (each projectSchema)
60+ Nothing ->
61−-- Project {projectAuthorId = 1, projectName = "rel8"}
61+ text "DELETE FROM" <+> ppTable from $$
62−-- Project {projectAuthorId = 2, projectName = "aeson"}
62+ text "WHERE false"
63−-- Project {projectAuthorId = 2, projectName = "text"}
63+ Just (usingDoc, i) ->
64−--
64+ text "DELETE FROM" <+> ppTable from $$
65−-- >>> :{
65+ usingDoc $$
66−-- delete c Delete
66+ ppWhere from (deleteWhere i) $$
67−-- { from = projectSchema
67+ ppReturning from returning
68−-- , deleteWhere = \p -> projectName p ==. lit "rel8"
69−-- , returning = Projection projectName
70−-- }
71−-- :}
72−-- ["rel8"]
73−--
74−-- >>> mapM_ print =<< select c (each projectSchema)
75−-- Project {projectAuthorId = 2, projectName = "aeson"}
76−-- Project {projectAuthorId = 2, projectName = "text"}
77−delete :: Connection -> Delete a -> IO a
78−delete c Delete {from, deleteWhere, returning} =
79− case returning of
80− NumberOfRowsAffected -> Hasql.run session c >>= either throwIO pure
81− where
82− session = Hasql.statement () statement
83− statement = Hasql.Statement bytes params decode prepare
84− bytes = encodeUtf8 $ Text.pack sql
85− params = Hasql.noParams
86− decode = Hasql.rowsAffected
87− prepare = False
88− sql = Opaleye.arrangeDeleteSql from' where'
89− where
90− from' = table $ toColumns <$> from
91− where' = toColumn . toPrimExpr . deleteWhere . fromColumns
92
68
93− Projection project -> Hasql.run session c >>= either throwIO pure
69+
94− where
70+-- | Run a 'Delete' statement.
95− session = Hasql.statement () statement
71+delete :: Delete a -> Hasql.Statement () a
96− statement = Hasql.Statement bytes params decode prepare
72+delete d@Delete {returning} = Hasql.Statement bytes params decode prepare
97− bytes = encodeUtf8 $ Text.pack sql
98− params = Hasql.noParams
99− decode = decoder project
100− prepare = False
101− sql =
102− Opaleye.arrangeDeleteReturningSql unpackspec from' where' project'
103− where
104− from' = table $ toColumns <$> from
105− where' = toColumn . toPrimExpr . deleteWhere . fromColumns
106− project' = toColumns . project . fromColumns
107 where
73 where
108− decoder :: forall exprs projection a. Serializable projection a
74+ bytes = encodeUtf8 $ Text.pack sql
109− => (exprs -> projection) -> Hasql.Result [a]
75+ params = Hasql.noParams
110− decoder _ = Hasql.rowList (parse @projection @a)
76+ decode = decodeReturning returning
77+ prepare = False
78+ sql = show doc
79+ doc = ppDelete d
src/Rel8/Statement/Insert.hs+44−81
@@ -2,39 +2,42 @@
2{-# language FlexibleContexts #-}
2{-# language FlexibleContexts #-}
3{-# language GADTs #-}
3{-# language GADTs #-}
4{-# language NamedFieldPuns #-}
4{-# language NamedFieldPuns #-}
5−{-# language ScopedTypeVariables #-}
5+{-# language RecordWildCards #-}
6{-# language StandaloneKindSignatures #-}
6{-# language StandaloneKindSignatures #-}
7−{-# language TypeApplications #-}
7+{-# language StrictData #-}
8
8
9module Rel8.Statement.Insert
9module Rel8.Statement.Insert
10 ( Insert(..)
10 ( Insert(..)
11− , OnConflict(..)
12 , insert
11 , insert
12+ , ppInsert
13+ , ppInto
13 )
14 )
14where
15where
15
16
16-- base
17-- base
17−import Control.Exception ( throwIO )
18+import Data.Foldable ( toList )
18import Data.Kind ( Type )
19import Data.Kind ( Type )
19−import Data.List.NonEmpty ( NonEmpty( (:|) ) )
20import Prelude
20import Prelude
21
21
22-- hasql
22-- hasql
23−import Hasql.Connection ( Connection )
24−import qualified Hasql.Decoders as Hasql
25import qualified Hasql.Encoders as Hasql
23import qualified Hasql.Encoders as Hasql
26−import qualified Hasql.Session as Hasql
27import qualified Hasql.Statement as Hasql
24import qualified Hasql.Statement as Hasql
28
25
26+-- opaleye
27+import qualified Opaleye.Internal.HaskellDB.Sql.Print as Opaleye
28+
29+-- pretty
30+import Text.PrettyPrint ( Doc, (<+>), ($$), parens, text )
31+
29-- rel8
32-- rel8
30−import qualified Opaleye.Internal.Manipulation as Opaleye
33+import Rel8.Query ( Query )
31−import qualified Opaleye.Manipulation as Opaleye
34+import Rel8.Schema.Name ( Name, Selects, ppColumn )
32−import Rel8.Schema.Table ( TableSchema )
35+import Rel8.Schema.Table ( TableSchema(..), ppTable )
33−import Rel8.Statement.Returning ( Returning( Projection, NumberOfRowsAffected ) )
36+import Rel8.Statement.OnConflict ( OnConflict, ppOnConflict )
34−import Rel8.Table ( fromColumns, toColumns )
37+import Rel8.Statement.Returning ( Returning, decodeReturning, ppReturning )
35−import Rel8.Table.Opaleye ( table, unpackspec )
38+import Rel8.Statement.Select ( ppRows )
36−import Rel8.Table.Recontextualize ( Inserts, Selects )
39+import Rel8.Table ( Table )
37−import Rel8.Table.Serialize ( Serializable, parse )
40+import Rel8.Table.Name ( showNames )
38
41
39-- text
42-- text
40import qualified Data.Text as Text ( pack )
43import qualified Data.Text as Text ( pack )
@@ -44,12 +47,13 @@ import Data.Text.Encoding ( encodeUtf8 )
44-- | The constituent parts of a SQL @INSERT@ statement.
47-- | The constituent parts of a SQL @INSERT@ statement.
45type Insert :: Type -> Type
48type Insert :: Type -> Type
46data Insert a where
49data Insert a where
47− Insert :: (Selects names exprs, Inserts exprs inserts) =>
50+ Insert :: Selects names exprs =>
48 { into :: TableSchema names
51 { into :: TableSchema names
49 -- ^ Which table to insert into.
52 -- ^ Which table to insert into.
50− , rows :: [inserts]
53+ , rows :: Query exprs
51− -- ^ The rows to insert.
54+ -- ^ The rows to insert. This can be an arbitrary query — use
55+ -- 'Rel8.values' insert a static list of rows.
52− , onConflict :: OnConflict
56+ , onConflict :: OnConflict names
53 -- ^ What to do if the inserted rows conflict with data already in the
57 -- ^ What to do if the inserted rows conflict with data already in the
54 -- table.
58 -- table.
55 , returning :: Returning names a
59 , returning :: Returning names a
@@ -58,69 +62,28 @@ data Insert a where
58 -> Insert a
62 -> Insert a
59
63
60
64
61−-- | @OnConflict@ allows you to add an @ON CONFLICT@ clause to an @INSERT@
65+ppInsert :: Insert a -> Doc
62−-- statement.
66+ppInsert Insert {..} =
63−data OnConflict
67+ text "INSERT INTO" <+>
64− = Abort -- ^ @ON CONFLICT ABORT@
68+ ppInto into $$
65− | DoNothing -- ^ @ON CONFLICT DO NOTHING@
69+ ppRows rows $$
70+ ppOnConflict into onConflict $$
71+ ppReturning into returning
66
72
67
73
68−-- | Run an @INSERT@ statement
74+ppInto :: Table Name a => TableSchema a -> Doc
69−--
75+ppInto table@TableSchema {columns} =
70−-- >>> :{
76+ ppTable table <+>
71−-- insert c Insert
77+ parens (Opaleye.commaV ppColumn (toList (showNames columns)))
72−-- { into = authorSchema
73−-- , rows = [ lit Author{ authorName = "Gabriel Gonzales", authorId = AuthorId 4, authorUrl = Just "https://haskellforall.com" } ]
74−-- , onConflict = Abort
75−-- , returning = NumberOfRowsAffected
76−-- }
77−-- :}
78−-- 1
79−insert :: Connection -> Insert a -> IO a
80−insert c Insert {into, rows, onConflict, returning} =
81− case (rows, returning) of
82− ([], NumberOfRowsAffected) -> pure 0
83− ([], Projection _) -> pure []
84
78
85− (x:xs, NumberOfRowsAffected) -> Hasql.run session c >>= either throwIO pure
86− where
87− session = Hasql.statement () statement
88− statement = Hasql.Statement bytes params decode prepare
89− bytes = encodeUtf8 $ Text.pack sql
90− params = Hasql.noParams
91− decode = Hasql.rowsAffected
92− prepare = False
93− sql = Opaleye.arrangeInsertManySql into' rows' onConflict'
94− where
95− into' = table $ toColumns <$> into
96− rows' = toColumns <$> x :| xs
97−
98− (x:xs, Projection project) -> Hasql.run session c >>= either throwIO pure
99− where
100− session = Hasql.statement () statement
101− statement = Hasql.Statement bytes params decode prepare
102− bytes = encodeUtf8 $ Text.pack sql
103− params = Hasql.noParams
104− decode = decoder project
105− prepare = False
106− sql =
107− Opaleye.arrangeInsertManyReturningSql
108− unpackspec
109− into'
110− rows'
111− project'
112− onConflict'
113− where
114− into' = table $ toColumns <$> into
115− rows' = toColumns <$> x :| xs
116− project' = toColumns . project . fromColumns
117
79
80+-- | Run an 'Insert' statement.
81+insert :: Insert a -> Hasql.Statement () a
82+insert i@Insert {returning} = Hasql.Statement bytes params decode prepare
118 where
83 where
119− onConflict' =
84+ bytes = encodeUtf8 $ Text.pack sql
120− case onConflict of
85+ params = Hasql.noParams
121− DoNothing -> Just Opaleye.DoNothing
86+ decode = decodeReturning returning
122− Abort -> Nothing
87+ prepare = False
123−
88+ sql = show doc
124− decoder :: forall exprs projection a. Serializable projection a
89+ doc = ppInsert i
125− => (exprs -> projection) -> Hasql.Result [a]
126− decoder _ = Hasql.rowList (parse @projection @a)
src/Rel8/Statement/OnConflict.hsnew file+106
@@ -0,0 +1,106 @@
1+{-# language DuplicateRecordFields #-}
2+{-# language FlexibleContexts #-}
3+{-# language GADTs #-}
4+{-# language LambdaCase #-}
5+{-# language NamedFieldPuns #-}
6+{-# language RecordWildCards #-}
7+{-# language StandaloneKindSignatures #-}
8+{-# language StrictData #-}
9+
10+module Rel8.Statement.OnConflict
11+ ( OnConflict(..)
12+ , Upsert(..)
13+ , ppOnConflict
14+ )
15+where
16+
17+-- base
18+import Data.Foldable ( toList )
19+import Data.Kind ( Type )
20+import Prelude
21+
22+-- opaleye
23+import qualified Opaleye.Internal.HaskellDB.Sql.Print as Opaleye
24+
25+-- pretty
26+import Text.PrettyPrint ( Doc, (<+>), ($$), parens, text )
27+
28+-- rel8
29+import Rel8.Expr ( Expr )
30+import Rel8.Schema.Name ( Name, Selects, ppColumn )
31+import Rel8.Schema.Table ( TableSchema(..) )
32+import Rel8.Statement.Set ( ppSet )
33+import Rel8.Statement.Where ( ppWhere )
34+import Rel8.Table ( Table, toColumns )
35+import Rel8.Table.Cols ( Cols( Cols ) )
36+import Rel8.Table.Name ( showNames )
37+import Rel8.Table.Opaleye ( attributes )
38+import Rel8.Table.Projection ( Projecting, Projection, apply )
39+
40+
41+-- | 'OnConflict' represents the @ON CONFLICT@ clause of an @INSERT@
42+-- statement. This specifies what ought to happen when one or more of the
43+-- rows proposed for insertion conflict with an existing row in the table.
44+type OnConflict :: Type -> Type
45+data OnConflict names
46+ = Abort
47+ -- ^ Abort the transaction if there are conflicting rows (Postgres' default)
48+ | DoNothing
49+ -- ^ @ON CONFLICT DO NOTHING@
50+ | DoUpdate (Upsert names)
51+ -- ^ @ON CONFLICT DO UPDATE@
52+
53+
54+-- | The @ON CONFLICT (...) DO UPDATE@ clause of an @INSERT@ statement, also
55+-- known as \"upsert\".
56+--
57+-- When an existing row conflicts with a row proposed for insertion,
58+-- @ON CONFLICT DO UPDATE@ allows you to instead update this existing row. The
59+-- conflicting row proposed for insertion is then \"excluded\", but its values
60+-- can still be referenced from the @SET@ and @WHERE@ clauses of the @UPDATE@
61+-- statement.
62+--
63+-- Upsert in Postgres requires an explicit set of \"conflict targets\" — the
64+-- set of columns comprising the @UNIQUE@ index from conflicts with which we
65+-- would like to recover.
66+type Upsert :: Type -> Type
67+data Upsert names where
68+ Upsert :: (Selects names exprs, Projecting names index, excluded ~ exprs) =>
69+ { index :: Projection names index
70+ -- ^ The set of conflict targets, projected from the set of columns for
71+ -- the whole table
72+ , set :: excluded -> exprs -> exprs
73+ -- ^ How to update each selected row.
74+ , updateWhere :: excluded -> exprs -> Expr Bool
75+ -- ^ Which rows to select for update.
76+ }
77+ -> Upsert names
78+
79+
80+ppOnConflict :: TableSchema names -> OnConflict names -> Doc
81+ppOnConflict schema = \case
82+ Abort -> mempty
83+ DoNothing -> text "ON CONFLICT DO NOTHING"
84+ DoUpdate upsert -> ppUpsert schema upsert
85+
86+
87+ppUpsert :: TableSchema names -> Upsert names -> Doc
88+ppUpsert schema@TableSchema {columns} Upsert {..} =
89+ text "ON CONFLICT" <+>
90+ ppIndex schema index <+>
91+ text "DO UPDATE" $$
92+ ppSet schema (set excluded) $$
93+ ppWhere schema (updateWhere excluded)
94+ where
95+ excluded = attributes TableSchema
96+ { schema = Nothing
97+ , name = "excluded"
98+ , columns
99+ }
100+
101+
102+ppIndex :: (Table Name names, Projecting names index)
103+ => TableSchema names -> Projection names index -> Doc
104+ppIndex TableSchema {columns} index =
105+ parens $ Opaleye.commaV ppColumn $ toList $
106+ showNames $ Cols $ apply index $ toColumns columns
src/Rel8/Statement/Returning.hs+115−11
@@ -1,29 +1,133 @@
1{-# language GADTs #-}
1{-# language GADTs #-}
2+{-# language LambdaCase #-}
3+{-# language NamedFieldPuns #-}
4+{-# language RankNTypes #-}
5+{-# language ScopedTypeVariables #-}
2{-# language StandaloneKindSignatures #-}
6{-# language StandaloneKindSignatures #-}
7+{-# language StrictData #-}
8+{-# language TypeApplications #-}
3
9
4module Rel8.Statement.Returning
10module Rel8.Statement.Returning
5− ( Returning(..)
11+ ( Returning( NumberOfRowsAffected, Projection )
12+ , decodeReturning
13+ , ppReturning
6 )
14 )
7where
15where
8
16
9-- base
17-- base
18+import Control.Applicative ( liftA2 )
19+import Data.Foldable ( toList )
10import Data.Int ( Int64 )
20import Data.Int ( Int64 )
11import Data.Kind ( Type )
21import Data.Kind ( Type )
22+import Data.List.NonEmpty ( NonEmpty )
12−import Prelude ()
23+import Prelude
24+
25+-- hasql
26+import qualified Hasql.Decoders as Hasql
27+
28+-- opaleye
29+import qualified Opaleye.Internal.HaskellDB.PrimQuery as Opaleye
30+import qualified Opaleye.Internal.HaskellDB.Sql.Print as Opaleye
31+import qualified Opaleye.Internal.Sql as Opaleye
32+
33+-- pretty
34+import Text.PrettyPrint ( Doc, (<+>), text )
13
35
14-- rel8
36-- rel8
15−import Rel8.Table.Recontextualize ( Selects )
37+import Rel8.Schema.Name ( Selects )
38+import Rel8.Schema.Table ( TableSchema(..) )
39+import Rel8.Table.Opaleye ( castTable, exprs, view )
16−import Rel8.Table.Serialize ( Serializable )
40+import Rel8.Table.Serialize ( Serializable, parse )
17
41
42+-- semigropuoids
43+import Data.Functor.Apply ( Apply, (<.>) )
18
44
45+
19−-- | @INSERT@, @UPDATE@ and @DELETE@ all support returning either the number of
46+-- | 'Rel8.Insert', 'Rel8.Update' and 'Rel8.Delete' all support returning either
20−-- rows affected, or the actual rows modified. 'Projection' allows you to
47+-- the number of rows affected, or the actual rows modified.
21−-- project out of these returned rows, which can be useful if you want to log
22−-- exactly which rows were deleted, or to view a generated id (for example, if
23−-- using a column with an autoincrementing counter as a default value).
24type Returning :: Type -> Type -> Type
48type Returning :: Type -> Type -> Type
25data Returning names a where
49data Returning names a where
50+ Pure :: a -> Returning names a
51+ Ap :: Returning names (a -> b) -> Returning names a -> Returning names b
52+
53+ -- | Return the number of rows affected.
26 NumberOfRowsAffected :: Returning names Int64
54 NumberOfRowsAffected :: Returning names Int64
55+
56+ -- | 'Projection' allows you to project out of the affected rows, which can
57+ -- be useful if you want to log exactly which rows were deleted, or to view
58+ -- a generated id (for example, if using a column with an autoincrementing
59+ -- counter via 'Rel8.nextval').
27− Projection :: (Selects names exprs, Serializable projection a)
60+ Projection :: (Selects names exprs, Serializable returning a)
28− => (exprs -> projection)
61+ => (exprs -> returning)
29 -> Returning names [a]
62 -> Returning names [a]
63+
64+
65+instance Functor (Returning names) where
66+ fmap f = \case
67+ Pure a -> Pure (f a)
68+ Ap g a -> Ap (fmap (f .) g) a
69+ m -> Ap (Pure f) m
70+
71+
72+instance Apply (Returning names) where
73+ (<.>) = Ap
74+
75+
76+instance Applicative (Returning names) where
77+ pure = Pure
78+ (<*>) = Ap
79+
80+
81+projections :: ()
82+ => TableSchema names -> Returning names a -> Maybe (NonEmpty Opaleye.PrimExpr)
83+projections schema@TableSchema {columns} = \case
84+ Pure _ -> Nothing
85+ Ap f a -> projections schema f <> projections schema a
86+ NumberOfRowsAffected -> Nothing
87+ Projection f -> Just (exprs (castTable (f (view columns))))
88+
89+
90+runReturning :: ()
91+ => ((Int64 -> a) -> r)
92+ -> (forall x. Hasql.Row x -> ([x] -> a) -> r)
93+ -> Returning names a
94+ -> r
95+runReturning rowCount rowList = \case
96+ Pure a -> rowCount (const a)
97+ Ap fs as ->
98+ runReturning
99+ (\withCount ->
100+ runReturning
101+ (\withCount' -> rowCount (withCount <*> withCount'))
102+ (\decoder -> rowList decoder . liftA2 withCount length64)
103+ as)
104+ (\decoder withRows ->
105+ runReturning
106+ (\withCount -> rowList decoder $ withRows <*> withCount . length64)
107+ (\decoder' withRows' ->
108+ rowList (liftA2 (,) decoder decoder') $
109+ withRows <$> fmap fst <*> withRows' . fmap snd)
110+ as)
111+ fs
112+ NumberOfRowsAffected -> rowCount id
113+ Projection (_ :: exprs -> returning) -> rowList decoder' id
114+ where
115+ decoder' = parse @returning
116+ where
117+ length64 :: Foldable f => f x -> Int64
118+ length64 = fromIntegral . length
119+
120+
121+decodeReturning :: Returning names a -> Hasql.Result a
122+decodeReturning = runReturning
123+ (<$> Hasql.rowsAffected)
124+ (\decoder withRows -> withRows <$> Hasql.rowList decoder)
125+
126+
127+ppReturning :: TableSchema names -> Returning names a -> Doc
128+ppReturning schema returning = case projections schema returning of
129+ Nothing -> mempty
130+ Just columns ->
131+ text "RETURNING" <+> Opaleye.commaV Opaleye.ppSqlExpr (toList sqlExprs)
132+ where
133+ sqlExprs = Opaleye.sqlExpr <$> columns
src/Rel8/Statement/SQL.hsnew file+29
@@ -0,0 +1,29 @@
1+module Rel8.Statement.SQL
2+ ( showDelete
3+ , showInsert
4+ , showUpdate
5+ )
6+where
7+
8+-- base
9+import Prelude
10+
11+-- rel8
12+import Rel8.Statement.Delete ( Delete, ppDelete )
13+import Rel8.Statement.Insert ( Insert, ppInsert )
14+import Rel8.Statement.Update ( Update, ppUpdate )
15+
16+
17+-- | Convert a 'Delete' to a 'String' containing a @DELETE@ statement.
18+showDelete :: Delete a -> String
19+showDelete = show . ppDelete
20+
21+
22+-- | Convert an 'Insert' to a 'String' containing an @INSERT@ statement.
23+showInsert :: Insert a -> String
24+showInsert = show . ppInsert
25+
26+
27+-- | Convert an 'Update' to a 'String' containing an @UPDATE@ statement.
28+showUpdate :: Update a -> String
29+showUpdate = show . ppUpdate
src/Rel8/Statement/Select.hs+122−36
@@ -1,61 +1,147 @@
1+{-# language DeriveTraversable #-}
2+{-# language DerivingStrategies #-}
3+{-# language FlexibleContexts #-}
4+{-# language MonoLocalBinds #-}
1{-# language ScopedTypeVariables #-}
5{-# language ScopedTypeVariables #-}
6+{-# language StandaloneKindSignatures #-}
2{-# language TypeApplications #-}
7{-# language TypeApplications #-}
3
8
4module Rel8.Statement.Select
9module Rel8.Statement.Select
5 ( select
10 ( select
6− , selectWithNames
11+ , ppSelect
12+
13+ , Optimized(..)
14+ , ppPrimSelect
15+ , ppRows
7 )
16 )
8where
17where
9
18
10-- base
19-- base
11−import Control.Exception ( throwIO )
20+import Data.Foldable ( toList )
21+import Data.Kind ( Type )
22+import Data.Void ( Void )
12−import Prelude
23+import Prelude hiding ( undefined )
13
24
14-- hasql
25-- hasql
15−import Hasql.Connection ( Connection )
16import qualified Hasql.Decoders as Hasql
26import qualified Hasql.Decoders as Hasql
17import qualified Hasql.Encoders as Hasql
27import qualified Hasql.Encoders as Hasql
18−import qualified Hasql.Session as Hasql
19import qualified Hasql.Statement as Hasql
28import qualified Hasql.Statement as Hasql
20
29
30+-- opaleye
31+import qualified Opaleye.Internal.HaskellDB.PrimQuery as Opaleye
32+import qualified Opaleye.Internal.HaskellDB.Sql as Opaleye
33+import qualified Opaleye.Internal.HaskellDB.Sql.Print as Opaleye
34+import qualified Opaleye.Internal.PrimQuery as Opaleye
35+import qualified Opaleye.Internal.Print as Opaleye
36+import qualified Opaleye.Internal.Optimize as Opaleye
37+import qualified Opaleye.Internal.QueryArr as Opaleye hiding ( Select )
38+import qualified Opaleye.Internal.Sql as Opaleye hiding ( Values )
39+import qualified Opaleye.Internal.Tag as Opaleye
40+
41+-- pretty
42+import Text.PrettyPrint ( Doc )
43+
21-- rel8
44-- rel8
45+import Rel8.Expr ( Expr )
46+import Rel8.Expr.Bool ( false )
47+import Rel8.Expr.Opaleye ( toPrimExpr )
22import Rel8.Query ( Query )
48import Rel8.Query ( Query )
23−import Rel8.Query.SQL ( sqlForQuery, sqlForQueryWithNames )
49+import Rel8.Query.Opaleye ( toOpaleye )
50+import Rel8.Schema.Name ( Selects )
51+import Rel8.Table ( Table )
52+import Rel8.Table.Cols ( toCols )
53+import Rel8.Table.Name ( namesFromLabels )
54+import Rel8.Table.Opaleye ( castTable, exprsWithNames )
24−import Rel8.Table.Recontextualize ( Selects )
55+import qualified Rel8.Table.Opaleye as T
25import Rel8.Table.Serialize ( Serializable, parse )
56import Rel8.Table.Serialize ( Serializable, parse )
57+import Rel8.Table.Undefined ( undefined )
26
58
27-- text
59-- text
28import qualified Data.Text as Text
60import qualified Data.Text as Text
29import Data.Text.Encoding ( encodeUtf8 )
61import Data.Text.Encoding ( encodeUtf8 )
30
62
31
63
32−-- | Run a @SELECT@ query, returning all rows.
64+-- | Run a @SELECT@ statement, returning all rows.
33select :: forall exprs a. Serializable exprs a
65select :: forall exprs a. Serializable exprs a
34− => Connection -> Query exprs -> IO [a]
66+ => Query exprs -> Hasql.Statement () [a]
35−select c query = case sqlForQuery query of
67+select query = Hasql.Statement bytes params decode prepare
36− Nothing -> pure []
68+ where
37− Just sql -> Hasql.run session c >>= either throwIO pure
69+ bytes = encodeUtf8 (Text.pack sql)
38− where
70+ params = Hasql.noParams
39− session = Hasql.statement () statement
71+ decode = Hasql.rowList (parse @exprs @a)
40− statement = Hasql.Statement bytes params decode prepare
72+ prepare = False
41− bytes = encodeUtf8 (Text.pack sql)
73+ sql = show doc
42− params = Hasql.noParams
74+ doc = ppSelect query
43− decode = Hasql.rowList (parse @exprs @a)
75+
44− prepare = False
76+
45−
77+ppSelect :: Table Expr a => Query a -> Doc
46−
78+ppSelect query =
47−selectWithNames :: forall exprs a names.
79+ Opaleye.ppSql $ primSelectWith names (toCols exprs') primQuery'
80+ where
81+ names = namesFromLabels
82+ (exprs, primQuery, _) =
83+ Opaleye.runSimpleQueryArrStart (toOpaleye query) ()
84+ (exprs', primQuery') = case optimize primQuery of
85+ Empty -> (undefined, Opaleye.Product (pure (pure Opaleye.Unit)) never)
86+ Unit -> (exprs, Opaleye.Unit)
87+ Optimized pq -> (exprs, pq)
88+ never = pure (toPrimExpr false)
89+
90+
91+ppRows :: Table Expr a => Query a -> Doc
92+ppRows query = case optimize primQuery of
93+ -- Special case VALUES because we can't use DEFAULT inside a SELECT
94+ Optimized (Opaleye.Values symbols rows)
95+ | eqSymbols symbols (toList (T.exprs a)) ->
96+ Opaleye.ppValues_ (map Opaleye.sqlExpr <$> toList rows)
97+ _ -> ppSelect query
98+ where
99+ (a, primQuery, _) = Opaleye.runSimpleQueryArrStart (toOpaleye query) ()
100+
101+ eqSymbols (symbol : symbols) (Opaleye.AttrExpr symbol' : exprs)
102+ | eqSymbol symbol symbol' = eqSymbols symbols exprs
103+ | otherwise = False
104+ eqSymbols [] [] = True
105+ eqSymbols _ _ = False
106+
107+ eqSymbol
108+ (Opaleye.Symbol name (Opaleye.UnsafeTag tag))
109+ (Opaleye.Symbol name' (Opaleye.UnsafeTag tag'))
110+ = name == name' && tag == tag'
111+
112+
113+ppPrimSelect :: Query a -> (Optimized Doc, a)
114+ppPrimSelect query =
115+ (Opaleye.ppSql . primSelect <$> optimize primQuery, a)
116+ where
117+ (a, primQuery, _) = Opaleye.runSimpleQueryArrStart (toOpaleye query) ()
118+
119+
120+type Optimized :: Type -> Type
121+data Optimized a = Empty | Unit | Optimized a
122+ deriving stock (Functor, Foldable, Traversable, Show)
123+
124+
125+optimize :: Opaleye.PrimQuery' a -> Optimized (Opaleye.PrimQuery' Void)
126+optimize query = case Opaleye.removeEmpty (Opaleye.optimize query) of
127+ Nothing -> Empty
128+ Just Opaleye.Unit -> Unit
129+ Just query' -> Optimized query'
130+
131+
132+primSelect :: Opaleye.PrimQuery' Void -> Opaleye.Select
133+primSelect = Opaleye.foldPrimQuery Opaleye.sqlQueryGenerator
134+
135+
48− ( Selects names exprs
136+primSelectWith :: Selects names exprs
49− , Serializable exprs a
137+ => names -> exprs -> Opaleye.PrimQuery' Void -> Opaleye.Select
50− )
138+primSelectWith names exprs query =
51− => Connection -> names -> Query exprs -> IO [a]
139+ Opaleye.SelectFrom $ Opaleye.newSelect
52−selectWithNames c names query = case sqlForQueryWithNames names query of
140+ { Opaleye.attrs = Opaleye.SelectAttrs attrs
53− Nothing -> pure []
141+ , Opaleye.tables = Opaleye.oneTable (primSelect query)
54− Just sql -> Hasql.run session c >>= either throwIO pure
142+ }
55− where
143+ where
56− session = Hasql.statement () statement
144+ attrs = makeAttr <$> exprsWithNames names (castTable exprs)
57− statement = Hasql.Statement bytes params decode prepare
145+ where
58− bytes = encodeUtf8 (Text.pack sql)
146+ makeAttr (label, expr) =
59− params = Hasql.noParams
147+ (Opaleye.sqlExpr expr, Just (Opaleye.SqlColumn label))
60− decode = Hasql.rowList (parse @exprs @a)
61− prepare = False
src/Rel8/Statement/Set.hsnew file+33
@@ -0,0 +1,33 @@
1+{-# language MonoLocalBinds #-}
2+{-# language NamedFieldPuns #-}
3+
4+module Rel8.Statement.Set
5+ ( ppSet
6+ )
7+where
8+
9+-- base
10+import Data.Foldable ( toList )
11+import Prelude ()
12+
13+-- opaleye
14+import qualified Opaleye.Internal.HaskellDB.Sql.Print as Opaleye
15+import qualified Opaleye.Internal.Sql as Opaleye
16+
17+-- pretty
18+import Text.PrettyPrint ( Doc, (<+>), equals, text )
19+
20+-- rel8
21+import Rel8.Schema.Name ( Selects, ppColumn )
22+import Rel8.Schema.Table ( TableSchema(..) )
23+import Rel8.Table.Opaleye ( attributes, exprsWithNames )
24+
25+
26+ppSet :: Selects names exprs
27+ => TableSchema names -> (exprs -> exprs) -> Doc
28+ppSet schema@TableSchema {columns} f =
29+ text "SET" <+> Opaleye.commaV ppAssign (toList assigns)
30+ where
31+ assigns = exprsWithNames columns (f (attributes schema))
32+ ppAssign (column, expr) =
33+ ppColumn column <+> equals <+> Opaleye.ppSqlExpr (Opaleye.sqlExpr expr)
src/Rel8/Statement/Update.hs+39−81
@@ -1,43 +1,37 @@
1+{-# language DuplicateRecordFields #-}
1{-# language GADTs #-}
2{-# language GADTs #-}
2{-# language NamedFieldPuns #-}
3{-# language NamedFieldPuns #-}
3−{-# language ScopedTypeVariables #-}
4+{-# language RecordWildCards #-}
4{-# language StandaloneKindSignatures #-}
5{-# language StandaloneKindSignatures #-}
5−{-# language TypeApplications #-}
6+{-# language StrictData #-}
6
7
7module Rel8.Statement.Update
8module Rel8.Statement.Update
8 ( Update(..)
9 ( Update(..)
9 , update
10 , update
11+ , ppUpdate
10 )
12 )
11where
13where
12
14
13-- base
15-- base
14−import Control.Exception ( throwIO )
15import Data.Kind ( Type )
16import Data.Kind ( Type )
16import Prelude
17import Prelude
17
18
18-- hasql
19-- hasql
19−import Hasql.Connection ( Connection )
20−import qualified Hasql.Decoders as Hasql
21import qualified Hasql.Encoders as Hasql
20import qualified Hasql.Encoders as Hasql
22−import qualified Hasql.Session as Hasql
23import qualified Hasql.Statement as Hasql
21import qualified Hasql.Statement as Hasql
24
22
25−-- opaleye
23+-- pretty
26−import qualified Opaleye.Internal.Manipulation as Opaleye
24+import Text.PrettyPrint ( Doc, (<+>), ($$), text )
27−
28−-- profunctors
29−import Data.Profunctor ( lmap )
30
25
31-- rel8
26-- rel8
32import Rel8.Expr ( Expr )
27import Rel8.Expr ( Expr )
33−import Rel8.Expr.Opaleye ( toColumn, toPrimExpr )
28+import Rel8.Query ( Query )
29+import Rel8.Schema.Name ( Selects )
34−import Rel8.Schema.Table ( TableSchema )
30+import Rel8.Schema.Table ( TableSchema(..), ppTable )
35−import Rel8.Statement.Returning ( Returning( Projection, NumberOfRowsAffected ) )
31+import Rel8.Statement.Returning ( Returning, decodeReturning, ppReturning )
36−import Rel8.Table ( fromColumns, toColumns )
32+import Rel8.Statement.Set ( ppSet )
37−import Rel8.Table.Insert ( toInsert )
33+import Rel8.Statement.Using ( ppFrom )
38−import Rel8.Table.Opaleye ( table, unpackspec )
34+import Rel8.Statement.Where ( ppWhere )
39−import Rel8.Table.Recontextualize ( Selects )
40−import Rel8.Table.Serialize ( Serializable, parse )
41
35
42-- text
36-- text
43import qualified Data.Text as Text
37import qualified Data.Text as Text
@@ -50,9 +44,12 @@ data Update a where
50 Update :: Selects names exprs =>
44 Update :: Selects names exprs =>
51 { target :: TableSchema names
45 { target :: TableSchema names
52 -- ^ Which table to update.
46 -- ^ Which table to update.
47+ , from :: Query from
48+ -- ^ @FROM@ clause — this can be used to join against other tables,
49+ -- and its results can be referenced in the @SET@ and @WHERE@ clauses.
53− , set :: exprs -> exprs
50+ , set :: from -> exprs -> exprs
54 -- ^ How to update each selected row.
51 -- ^ How to update each selected row.
55− , updateWhere :: exprs -> Expr Bool
52+ , updateWhere :: from -> exprs -> Expr Bool
56 -- ^ Which rows to select for update.
53 -- ^ Which rows to select for update.
57 , returning :: Returning names a
54 , returning :: Returning names a
58 -- ^ What to return from the @UPDATE@ statement.
55 -- ^ What to return from the @UPDATE@ statement.
@@ -60,66 +57,27 @@ data Update a where
60 -> Update a
57 -> Update a
61
58
62
59
63−-- | Run an @UPDATE@ statement.
60+ppUpdate :: Update a -> Doc
64−--
61+ppUpdate Update {..} = case ppFrom from of
65−-- >>> mapM_ print =<< select c (each projectSchema)
62+ Nothing ->
66−-- Project {projectAuthorId = 1, projectName = "rel8"}
63+ text "UPDATE" <+> ppTable target $$
67−-- Project {projectAuthorId = 2, projectName = "aeson"}
64+ ppSet target id $$
68−-- Project {projectAuthorId = 2, projectName = "text"}
65+ text "WHERE false"
69−--
66+ Just (fromDoc, i) ->
70−-- >>> :{
67+ text "UPDATE" <+> ppTable target $$
71−-- update c Update
68+ ppSet target (set i) $$
72−-- { target = projectSchema
69+ fromDoc $$
73−-- , set = \p -> p { projectName = "Rel8!" }
70+ ppWhere target (updateWhere i) $$
74−-- , updateWhere = \p -> projectName p ==. lit "rel8"
71+ ppReturning target returning
75−-- , returning = NumberOfRowsAffected
76−-- }
77−-- :}
78−-- 1
79−--
80−-- >>> mapM_ print =<< select c (each projectSchema)
81−-- Project {projectAuthorId = 2, projectName = "aeson"}
82−-- Project {projectAuthorId = 2, projectName = "text"}
83−-- Project {projectAuthorId = 1, projectName = "Rel8!"}
84−update :: Connection -> Update a -> IO a
85−update c Update {target, set, updateWhere, returning} =
86− case returning of
87− NumberOfRowsAffected -> Hasql.run session c >>= either throwIO pure
88− where
89− session = Hasql.statement () statement
90− statement = Hasql.Statement bytes params decode prepare
91− bytes = encodeUtf8 $ Text.pack sql
92− params = Hasql.noParams
93− decode = Hasql.rowsAffected
94− prepare = False
95− sql = Opaleye.arrangeUpdateSql target' set' where'
96− where
97− target' = lmap toInsert $ table $ toColumns <$> target
98− set' = toColumns . set . fromColumns
99− where' = toColumn . toPrimExpr . updateWhere . fromColumns
100
72
101− Projection project -> Hasql.run session c >>= either throwIO pure
102− where
103− session = Hasql.statement () statement
104− statement = Hasql.Statement bytes params decode prepare
105− bytes = encodeUtf8 $ Text.pack sql
106− params = Hasql.noParams
107− decode = decoder project
108− prepare = False
109− sql =
110− Opaleye.arrangeUpdateReturningSql
111− unpackspec
112− target'
113− set'
114− where'
115− project'
116− where
117− target' = lmap toInsert $ table $ toColumns <$> target
118− set' = toColumns . set . fromColumns
119− where' = toColumn . toPrimExpr . updateWhere . fromColumns
120− project' = toColumns . project . fromColumns
121
73
74+-- | Run an @UPDATE@ statement.
75+update :: Update a -> Hasql.Statement () a
76+update u@Update {returning} = Hasql.Statement bytes params decode prepare
122 where
77 where
123− decoder :: forall exprs projection a. Serializable projection a
78+ bytes = encodeUtf8 $ Text.pack sql
124− => (exprs -> projection) -> Hasql.Result [a]
79+ params = Hasql.noParams
125− decoder _ = Hasql.rowList (parse @projection @a)
80+ decode = decodeReturning returning
81+ prepare = False
82+ sql = show doc
83+ doc = ppUpdate u
src/Rel8/Statement/Using.hsnew file+36
@@ -0,0 +1,36 @@
1+module Rel8.Statement.Using
2+ ( ppFrom
3+ , ppUsing
4+ )
5+where
6+
7+-- base
8+import Prelude
9+
10+-- pretty
11+import Text.PrettyPrint ( Doc, (<+>), parens, text )
12+
13+-- rel8
14+import Rel8.Query ( Query )
15+import Rel8.Schema.Table ( TableSchema(..), ppTable )
16+import Rel8.Statement.Select ( Optimized(..), ppPrimSelect )
17+
18+
19+ppFrom :: Query a -> Maybe (Doc, a)
20+ppFrom = ppJoin "FROM"
21+
22+
23+ppUsing :: Query a -> Maybe (Doc, a)
24+ppUsing = ppJoin "USING"
25+
26+
27+ppJoin :: String -> Query a -> Maybe (Doc, a)
28+ppJoin clause join = do
29+ doc <- case ofrom of
30+ Empty -> Nothing
31+ Unit -> Just mempty
32+ Optimized doc -> Just $ text clause <+> parens doc <+> ppTable alias
33+ pure (doc, a)
34+ where
35+ alias = TableSchema {name = "T1", schema = Nothing, columns = ()}
36+ (ofrom, a) = ppPrimSelect join
src/Rel8/Statement/View.hs+48−29
@@ -1,59 +1,78 @@
1{-# language FlexibleContexts #-}
1{-# language FlexibleContexts #-}
2+{-# language MonoLocalBinds #-}
2
3
3module Rel8.Statement.View
4module Rel8.Statement.View
4 ( createView
5 ( createView
6+ , createOrReplaceView
5 )
7 )
6where
8where
7
9
8-- base
10-- base
9−import Control.Exception ( throwIO )
10−import Control.Monad ( (>=>) )
11−import Data.Foldable ( fold )
12−import Data.Maybe ( fromMaybe )
13import Prelude
11import Prelude
14
12
15-- hasql
13-- hasql
16−import Hasql.Connection ( Connection )
17import qualified Hasql.Decoders as Hasql
14import qualified Hasql.Decoders as Hasql
18import qualified Hasql.Encoders as Hasql
15import qualified Hasql.Encoders as Hasql
19−import qualified Hasql.Session as Hasql
20import qualified Hasql.Statement as Hasql
16import qualified Hasql.Statement as Hasql
21
17
22-- rel8
18-- rel8
23import Rel8.Query ( Query )
19import Rel8.Query ( Query )
24−import Rel8.Query.SQL ( sqlForQueryWithNames )
20+import Rel8.Schema.Name ( Selects )
25−import Rel8.Schema.Table ( TableSchema( TableSchema ) )
21+import Rel8.Schema.Table ( TableSchema )
26−import Rel8.Table.Alternative ( emptyTable )
22+import Rel8.Statement.Insert ( ppInto )
27−import Rel8.Table.Recontextualize ( Selects )
23+import Rel8.Statement.Select ( ppSelect )
24+
25+-- pretty
26+import Text.PrettyPrint ( Doc, (<+>), ($$), text )
28
27
29-- text
28-- text
30import qualified Data.Text as Text
29import qualified Data.Text as Text
31import Data.Text.Encoding ( encodeUtf8 )
30import Data.Text.Encoding ( encodeUtf8 )
32
31
33
32
33+data CreateView = Create | CreateOrReplace
34+
35+
36+-- | Given a 'TableSchema' and 'Query', @createView@ runs a @CREATE VIEW@
37+-- statement that will save the given query as a view. This can be useful if
38+-- you want to share Rel8 queries with other applications.
34createView :: Selects names exprs
39createView :: Selects names exprs
35− => TableSchema names -> Query exprs -> Connection -> IO ()
40+ => TableSchema names -> Query exprs -> Hasql.Statement () ()
36−createView (TableSchema name mschema names) query =
41+createView =
37− Hasql.run session >=> either throwIO pure
42+ createViewGeneric Create
43+
44+
45+-- | Given a 'TableSchema' and 'Query', @createOrReplaceView@ runs a
46+-- @CREATE OR REPLACE VIEW@ statement that will save the given query
47+-- as a view, replacing the current view definition if it exists and
48+-- adheres to the restrictions in place for replacing a view in
49+-- PostgreSQL.
50+createOrReplaceView :: Selects names exprs
51+ => TableSchema names -> Query exprs -> Hasql.Statement () ()
52+createOrReplaceView =
53+ createViewGeneric CreateOrReplace
54+
55+
56+createViewGeneric :: Selects names exprs
57+ => CreateView -> TableSchema names -> Query exprs -> Hasql.Statement () ()
58+createViewGeneric replace schema query =
59+ Hasql.Statement bytes params decode prepare
38 where
60 where
39− session = Hasql.statement () statement
40− statement = Hasql.Statement bytes params decode prepare
41 bytes = encodeUtf8 (Text.pack sql)
61 bytes = encodeUtf8 (Text.pack sql)
42 params = Hasql.noParams
62 params = Hasql.noParams
43 decode = Hasql.noResult
63 decode = Hasql.noResult
44 prepare = False
64 prepare = False
45− sql = "CREATE VIEW " <> title <> " WITH " <> select
65+ sql = show doc
46− where
66+ doc = ppCreateView schema query replace
47− title = case mschema of
67+
48− Nothing -> quote name
68+
49− Just schema -> quote schema <> "." <> quote name
69+ppCreateView :: Selects names exprs
50− select = fromMaybe fallback $ sqlForQueryWithNames names query
70+ => TableSchema names -> Query exprs -> CreateView -> Doc
51− where
71+ppCreateView schema query replace =
52− fallback = fold $ sqlForQueryWithNames names emptyTable
72+ createOrReplace replace <+>
53−
73+ ppInto schema $$
54−
74+ text "AS" <+>
55−quote :: String -> String
75+ ppSelect query
56−quote string = "\"" <> concatMap go string <> "\""
57 where
76 where
58− go '"' = "\"\""
77+ createOrReplace Create = text "CREATE VIEW"
59− go c = [c]
78+ createOrReplace CreateOrReplace = text "CREATE OR REPLACE VIEW"
src/Rel8/Statement/Where.hsnew file+31
@@ -0,0 +1,31 @@
1+{-# language MonoLocalBinds #-}
2+
3+module Rel8.Statement.Where
4+ ( ppWhere
5+ )
6+where
7+
8+-- base
9+import Prelude
10+
11+-- opaleye
12+import qualified Opaleye.Internal.HaskellDB.Sql.Print as Opaleye
13+import qualified Opaleye.Internal.Sql as Opaleye
14+
15+-- pretty
16+import Text.PrettyPrint ( Doc, (<+>), text )
17+
18+-- rel8
19+import Rel8.Expr ( Expr )
20+import Rel8.Expr.Opaleye ( toPrimExpr )
21+import Rel8.Schema.Name ( Selects )
22+import Rel8.Schema.Table ( TableSchema )
23+import Rel8.Table.Opaleye ( attributes )
24+
25+
26+ppWhere :: Selects names exprs
27+ => TableSchema names -> (exprs -> Expr Bool) -> Doc
28+ppWhere schema where_ = text "WHERE" <+> ppExpr condition
29+ where
30+ ppExpr = Opaleye.ppSqlExpr . Opaleye.sqlExpr . toPrimExpr
31+ condition = where_ (attributes schema)
src/Rel8/Table.hs+143−173
@@ -1,43 +1,46 @@
1+{-# language AllowAmbiguousTypes #-}
1{-# language DataKinds #-}
2{-# language DataKinds #-}
2−{-# language DisambiguateRecordFields #-}
3+{-# language DefaultSignatures #-}
3{-# language FlexibleContexts #-}
4{-# language FlexibleContexts #-}
4{-# language FlexibleInstances #-}
5{-# language FlexibleInstances #-}
5{-# language FunctionalDependencies #-}
6{-# language FunctionalDependencies #-}
7+{-# language ScopedTypeVariables #-}
6{-# language StandaloneKindSignatures #-}
8{-# language StandaloneKindSignatures #-}
9+{-# language TypeApplications #-}
7{-# language TypeFamilies #-}
10{-# language TypeFamilies #-}
8{-# language UndecidableInstances #-}
11{-# language UndecidableInstances #-}
9
12
10module Rel8.Table
13module Rel8.Table
14+ ( Table
11− ( Table (Columns, Context)
15+ ( Columns, Context, fromColumns, toColumns
12− , toColumns, fromColumns
16+ , FromExprs, fromResult, toResult
17+ , Transpose
18+ )
13 , Congruent
19 , Congruent
20+ , TTable, TColumns, TContext, TFromExprs, TTranspose
21+ , TSerialize
14 )
22 )
15where
23where
16
24
17-- base
25-- base
18import Data.Functor.Identity ( Identity( Identity ) )
26import Data.Functor.Identity ( Identity( Identity ) )
19import Data.Kind ( Constraint, Type )
27import Data.Kind ( Constraint, Type )
20−import Prelude
28+import GHC.Generics ( Generic, Rep, from, to )
29+import Prelude hiding ( null )
21
30
22-- rel8
31-- rel8
23−import Rel8.Aggregate ( Aggregate )
32+import Rel8.FCF ( Eval, Exp )
24−import Rel8.Expr ( Expr )
33+import Rel8.Generic.Map ( Map )
25−import Rel8.Opaque ( Opaque, Opaque1 )
34+import Rel8.Generic.Table.Record
26−import Rel8.Schema.Context
35+ ( GTable, GColumns, GContext, gfromColumns, gtoColumns
27− ( Col, Col'(..), Insertion(..), Name, IsSpecialContext
36+ , GSerialize, gfromResult, gtoResult
28 )
37 )
29−import Rel8.Schema.Context.Label ( Labelable, labeler, unlabeler )
38+import Rel8.Generic.Record ( Record(..) )
30−import Rel8.Schema.HTable ( HTable, hfield, hspecs, htabulate, htabulateA )
39+import Rel8.Schema.HTable ( HTable )
31−import Rel8.Schema.HTable.Identity ( HIdentity(..) )
40+import Rel8.Schema.HTable.Identity ( HIdentity( HIdentity ) )
32−import Rel8.Schema.HTable.Label ( HLabel, hlabel, hunlabel )
33−import Rel8.Schema.HTable.Pair ( HPair(..) )
34−import Rel8.Schema.HTable.Quartet ( HQuartet(..) )
35−import Rel8.Schema.HTable.Quintet ( HQuintet(..) )
36−import Rel8.Schema.HTable.Trio ( HTrio(..) )
37−import Rel8.Schema.HTable.Type ( HType( HType ) )
38import qualified Rel8.Schema.Kind as K
41import qualified Rel8.Schema.Kind as K
39−import Rel8.Schema.Nullability ( Sql )
42+import Rel8.Schema.Null ( Sql )
40−import Rel8.Schema.Spec ( SSpec( SSpec ), KnownSpec )
43+import Rel8.Schema.Result ( Result )
41import Rel8.Type ( DBType )
44import Rel8.Type ( DBType )
42
45
43
46
@@ -45,206 +48,173 @@ import Rel8.Type ( DBType )
45-- types that have a finite number of columns. Each of these columns contains
48-- types that have a finite number of columns. Each of these columns contains
46-- data under a shared context, and contexts describe how to interpret the
49-- data under a shared context, and contexts describe how to interpret the
47-- metadata about a column to a particular Haskell type. In Rel8, we have
50-- metadata about a column to a particular Haskell type. In Rel8, we have
48−-- contexts for expressions (the 'Expr' context), aggregations (the 'Aggregate'
51+-- contexts for expressions (the 'Rel8.Expr' context), aggregations (the
49−-- context), insert values (the 'Insert' contex), among others.
52+-- 'Rel8.Aggregate' context), insert values (the 'Rel8.Insert' contex), among
53+-- others.
50--
54--
51-- In typical usage of Rel8 you don't need to derive instances of 'Table'
55-- In typical usage of Rel8 you don't need to derive instances of 'Table'
52−-- yourself, as anything that's an instance of 'Rel8able' is always a 'Table'.
56+-- yourself, as anything that's an instance of 'Rel8.Rel8able' is always a
57+-- 'Table'.
53type Table :: K.Context -> Type -> Constraint
58type Table :: K.Context -> Type -> Constraint
59+class
60+ ( HTable (Columns a)
61+ , context ~ Context a
62+ , a ~ Transpose context a
63+ )
54−class (HTable (Columns a), context ~ Context a) => Table context a | a -> context where
64+ => Table context a | a -> context
65+ where
55 -- | The 'HTable' functor that describes the schema of this table.
66 -- | The 'HTable' functor that describes the schema of this table.
56 type Columns a :: K.HTable
67 type Columns a :: K.HTable
57
68
58 -- | The common context that all columns use as an interpretation.
69 -- | The common context that all columns use as an interpretation.
59 type Context a :: K.Context
70 type Context a :: K.Context
60
71
61− toColumns :: a -> Columns a (Col (Context a))
72+ -- | The @FromExprs@ type family maps a type in the @Expr@ context to the
62− fromColumns :: Columns a (Col (Context a)) -> a
73+ -- corresponding Haskell type.
74+ type FromExprs a :: Type
63
75
76+ type Transpose (context' :: K.Context) a :: Type
64
77
65−-- | Any 'HTable' is also a 'Table'.
66−instance (HTable t, x ~ IsSpecialContext context) =>
67− Table context (t (Col' x context))
68− where
69− type Columns (t (Col' x context)) = t
70− type Context (t (Col' x context)) = context
71
78
72− toColumns = id
79+ toColumns :: a -> Columns a context
73− fromColumns = id
80+ fromColumns :: Columns a context -> a
74
81
82+ fromResult :: Columns a Result -> FromExprs a
83+ toResult :: FromExprs a -> Columns a Result
75
84
76−-- | Any context is trivially a table.
85+ type Columns a = GColumns TColumns (Rep (Record a))
77−instance (KnownSpec spec, x ~ IsSpecialContext context) =>
86+ type Context a = GContext TContext (Rep (Record a))
78− Table context (Col' x context spec)
87+ type FromExprs a = Map TFromExprs a
79− where
88+ type Transpose context a = Map (TTranspose context) a
80− type Columns (Col' x context spec) = HIdentity spec
81− type Context (Col' x context spec) = context
82
89
90+ default toColumns ::
91+ ( Generic (Record a)
92+ , GTable (TTable context) TColumns (Rep (Record a))
93+ , Columns a ~ GColumns TColumns (Rep (Record a))
94+ )
95+ => a -> Columns a context
83− toColumns = HIdentity
96+ toColumns =
97+ gtoColumns @(TTable context) @TColumns toColumns .
98+ from .
99+ Record
100+
101+ default fromColumns ::
102+ ( Generic (Record a)
103+ , GTable (TTable context) TColumns (Rep (Record a))
104+ , Columns a ~ GColumns TColumns (Rep (Record a))
105+ )
106+ => Columns a context -> a
84− fromColumns = unHIdentity
107+ fromColumns =
85−
108+ unrecord .
86−
109+ to .
110+ gfromColumns @(TTable context) @TColumns fromColumns
111+
112+ default toResult ::
113+ ( Generic (Record (FromExprs a))
114+ , GSerialize TSerialize TColumns (Rep (Record a)) (Rep (Record (FromExprs a)))
115+ , Columns a ~ GColumns TColumns (Rep (Record a))
116+ )
117+ => FromExprs a -> Columns a Result
118+ toResult =
119+ gtoResult
120+ @TSerialize
121+ @TColumns
122+ @(Rep (Record a))
123+ @(Rep (Record (FromExprs a)))
124+ (\(_ :: proxy x) -> toResult @(Context x) @x) .
125+ from .
126+ Record
127+
128+ default fromResult ::
129+ ( Generic (Record (FromExprs a))
130+ , GSerialize TSerialize TColumns (Rep (Record a)) (Rep (Record (FromExprs a)))
131+ , Columns a ~ GColumns TColumns (Rep (Record a))
132+ )
133+ => Columns a Result -> FromExprs a
134+ fromResult =
135+ unrecord .
136+ to .
137+ gfromResult
138+ @TSerialize
139+ @TColumns
140+ @(Rep (Record a))
141+ @(Rep (Record (FromExprs a)))
142+ (\(_ :: proxy x) -> fromResult @(Context x) @x)
143+
144+
87−instance Table Expr a => Table Aggregate (Aggregate a) where
145+instance Sql DBType a => Table Result (Identity a) where
88− type Columns (Aggregate a) = Columns a
146+ type Columns (Identity a) = HIdentity a
89− type Context (Aggregate a) = Aggregate
147+ type Context (Identity a) = Result
148+ type FromExprs (Identity a) = a
149+ type Transpose to (Identity a) = to a
90
150
91− toColumns a = htabulate $ \field -> case hfield hspecs field of
151+ toColumns = HIdentity
92− SSpec {} -> Aggregation $ unDB . (`hfield` field) . toColumns <$> a
152+ fromColumns (HIdentity a) = a
93− fromColumns as = fmap fromColumns $ htabulateA $ \field ->
153+ toResult a = HIdentity (Identity a)
94− case hfield as field of
154+ fromResult (HIdentity (Identity a)) = a
95− Aggregation a -> DB <$> a
96
155
97
156
98−instance Sql DBType a => Table Expr (Expr a) where
157+data TTable :: K.Context -> Type -> Exp Constraint
99− type Columns (Expr a) = HType a
158+type instance Eval (TTable context a) = Table context a
100− type Context (Expr a) = Expr
101
159
102− toColumns a = HType (DB a)
103− fromColumns (HType (DB a)) = a
104
160
161+data TColumns :: Type -> Exp K.HTable
162+type instance Eval (TColumns a) = Columns a
105
163
106−instance Sql DBType a => Table Identity (Identity a) where
107− type Columns (Identity a) = HType a
108− type Context (Identity a) = Identity
109
164
110− toColumns (Identity a) = HType (Result a)
165+data TContext :: Type -> Exp K.Context
111− fromColumns (HType (Result a)) = Identity a
166+type instance Eval (TContext a) = Context a
112
167
113
168
114−instance Sql DBType a => Table Insertion (Insertion a) where
169+data TFromExprs :: Type -> Exp Type
115− type Columns (Insertion a) = HType a
170+type instance Eval (TFromExprs a) = FromExprs a
116− type Context (Insertion a) = Insertion
117
171
118− toColumns (Insertion a) = HType (RequiredInsert a)
119− fromColumns (HType (RequiredInsert a)) = Insertion a
120
172
173+data TTranspose :: K.Context -> Type -> Exp Type
174+type instance Eval (TTranspose context a) = Transpose context a
121
175
122−instance Sql DBType a => Table Name (Name a) where
123− type Columns (Name a) = HType a
124− type Context (Name a) = Name
125
176
126− toColumns a = HType (Col a)
177+data TSerialize :: Type -> Type -> Exp Constraint
127− fromColumns (HType (Col a)) = a
178+type instance Eval (TSerialize expr a) =
179+ ( Table (Context expr) expr
180+ , a ~ FromExprs expr
181+ )
128
182
129
183
130−instance
131− ( Table context a, Table context b
184+instance (Table context a, Table context b) => Table context (a, b)
132− , Labelable context
133− ) =>
134− Table context (a, b)
135− where
136− type Columns (a, b) =
137− HPair
138− (HLabel "fst" (Columns a))
139− (HLabel "snd" (Columns b))
140− type Context (a, b) = Context a
141−
142− toColumns (a, b) = HPair
143− { hfst = hlabel labeler $ toColumns a
144− , hsnd = hlabel labeler $ toColumns b
145− }
146− fromColumns (HPair a b) =
147− ( fromColumns $ hunlabel unlabeler a
148− , fromColumns $ hunlabel unlabeler b
149− )
150
185
151
186
152instance
187instance
153 ( Table context a, Table context b, Table context c
188 ( Table context a, Table context b, Table context c
154− , Labelable context
189+ )
155− ) => Table context (a, b, c)
190+ => Table context (a, b, c)
156− where
157− type Columns (a, b, c) =
158− HTrio
159− (HLabel "fst" (Columns a))
160− (HLabel "snd" (Columns b))
161− (HLabel "trd" (Columns c))
162− type Context (a, b, c) = Context a
163−
164− toColumns (a, b, c) = HTrio
165− { hfst = hlabel labeler $ toColumns a
166− , hsnd = hlabel labeler $ toColumns b
167− , htrd = hlabel labeler $ toColumns c
168− }
169− fromColumns (HTrio a b c) =
170− ( fromColumns $ hunlabel unlabeler a
171− , fromColumns $ hunlabel unlabeler b
172− , fromColumns $ hunlabel unlabeler c
173− )
174
191
175
192
176instance
193instance
177 ( Table context a, Table context b, Table context c, Table context d
194 ( Table context a, Table context b, Table context c, Table context d
178− , Labelable context
195+ )
179− ) => Table context (a, b, c, d)
196+ => Table context (a, b, c, d)
180− where
181− type Columns (a, b, c, d) =
182− HQuartet
183− (HLabel "fst" (Columns a))
184− (HLabel "snd" (Columns b))
185− (HLabel "trd" (Columns c))
186− (HLabel "frt" (Columns d))
187− type Context (a, b, c, d) = Context a
188−
189− toColumns (a, b, c, d) = HQuartet
190− { hfst = hlabel labeler $ toColumns a
191− , hsnd = hlabel labeler $ toColumns b
192− , htrd = hlabel labeler $ toColumns c
193− , hfrt = hlabel labeler $ toColumns d
194− }
195− fromColumns (HQuartet a b c d) =
196− ( fromColumns $ hunlabel unlabeler a
197− , fromColumns $ hunlabel unlabeler b
198− , fromColumns $ hunlabel unlabeler c
199− , fromColumns $ hunlabel unlabeler d
200− )
201
197
202
198
203instance
199instance
204 ( Table context a, Table context b, Table context c, Table context d
200 ( Table context a, Table context b, Table context c, Table context d
205 , Table context e
201 , Table context e
206− , Labelable context
202+ )
207− ) => Table context (a, b, c, d, e)
203+ => Table context (a, b, c, d, e)
208− where
209− type Columns (a, b, c, d, e) =
210− HQuintet
211− (HLabel "fst" (Columns a))
212− (HLabel "snd" (Columns b))
213− (HLabel "trd" (Columns c))
214− (HLabel "frt" (Columns d))
215− (HLabel "fft" (Columns e))
216− type Context (a, b, c, d, e) = Context a
217−
218− toColumns (a, b, c, d, e) = HQuintet
219− { hfst = hlabel labeler $ toColumns a
220− , hsnd = hlabel labeler $ toColumns b
221− , htrd = hlabel labeler $ toColumns c
222− , hfrt = hlabel labeler $ toColumns d
223− , hfft = hlabel labeler $ toColumns e
224− }
225− fromColumns (HQuintet a b c d e) =
226− ( fromColumns $ hunlabel unlabeler a
227− , fromColumns $ hunlabel unlabeler b
228− , fromColumns $ hunlabel unlabeler c
229− , fromColumns $ hunlabel unlabeler d
230− , fromColumns $ hunlabel unlabeler e
231− )
232−
233−
234−instance Table Expr Opaque where
235− type Columns Opaque = HType Opaque
236− type Context Opaque = Expr
237
204
238− fromColumns = error "opaque"
239− toColumns = error "opaque"
240
205
206+instance
207+ ( Table context a, Table context b, Table context c, Table context d
208+ , Table context e, Table context f
209+ )
210+ => Table context (a, b, c, d, e, f)
241
211
242−instance Table context (Opaque1 context a) where
243− type Columns (Opaque1 context a) = HType Opaque
244− type Context (Opaque1 context a) = context
245
212
246− fromColumns = error "opaque"
213+instance
247− toColumns = error "opaque"
214+ ( Table context a, Table context b, Table context c, Table context d
215+ , Table context e, Table context f, Table context g
216+ )
217+ => Table context (a, b, c, d, e, f, g)
248
218
249
219
250type Congruent :: Type -> Type -> Constraint
220type Congruent :: Type -> Type -> Constraint
src/Rel8/Table/ADT.hsnew file+173
@@ -0,0 +1,173 @@
1+{-# language AllowAmbiguousTypes #-}
2+{-# language DataKinds #-}
3+{-# language FlexibleContexts #-}
4+{-# language FlexibleInstances #-}
5+{-# language MultiParamTypeClasses #-}
6+{-# language RankNTypes #-}
7+{-# language ScopedTypeVariables #-}
8+{-# language StandaloneKindSignatures #-}
9+{-# language TypeApplications #-}
10+{-# language TypeFamilyDependencies #-}
11+{-# language UndecidableInstances #-}
12+{-# language UndecidableSuperClasses #-}
13+
14+module Rel8.Table.ADT
15+ ( ADT( ADT )
16+ , ADTable
17+ , BuildableADT
18+ , BuildADT, buildADT
19+ , ConstructableADT
20+ , ConstructADT, constructADT
21+ , DeconstructADT, deconstructADT
22+ , NameADT, nameADT
23+ , AggregateADT, aggregateADT
24+ , ADTRep
25+ )
26+where
27+
28+-- base
29+import Data.Kind ( Constraint, Type )
30+import GHC.Generics ( Generic, from, to )
31+import GHC.TypeLits ( Symbol )
32+import Prelude
33+
34+-- rel8
35+import Rel8.Aggregate ( Aggregate )
36+import Rel8.Expr ( Expr )
37+import Rel8.FCF ( Eval, Exp )
38+import Rel8.Generic.Construction
39+ ( GGBuildable
40+ , GGBuild, ggbuild
41+ , GGConstructable
42+ , GGConstruct, ggconstruct
43+ , GGDeconstruct, ggdeconstruct
44+ , GGName, ggname
45+ , GGAggregate, ggaggregate
46+ )
47+import Rel8.Generic.Record ( Record( Record ), unrecord )
48+import Rel8.Generic.Rel8able
49+ ( Rel8able
50+ , GRep, GColumns, gfromColumns, gtoColumns
51+ , GFromExprs, gfromResult, gtoResult
52+ , TSerialize, deserialize, serialize
53+ )
54+import qualified Rel8.Generic.Table.ADT as G
55+import qualified Rel8.Kind.Algebra as K
56+import Rel8.Schema.HTable ( HTable )
57+import qualified Rel8.Schema.Kind as K
58+import Rel8.Schema.Name ( Name )
59+import Rel8.Schema.Result ( Result )
60+import Rel8.Table ( Table, TColumns )
61+
62+
63+type ADT :: K.Rel8able -> K.Rel8able
64+newtype ADT t context = ADT (GColumnsADT t context)
65+
66+
67+instance ADTable t => Rel8able (ADT t) where
68+ type GColumns (ADT t) = GColumnsADT t
69+ type GFromExprs (ADT t) = t Result
70+
71+ gfromColumns _ = ADT
72+ gtoColumns _ (ADT a) = a
73+
74+ gfromResult =
75+ unrecord .
76+ to .
77+ G.gfromResultADT
78+ @TSerialize
79+ @TColumns
80+ @(Eval (ADTRep t Expr))
81+ @(Eval (ADTRep t Result))
82+ (\(_ :: proxy x) -> deserialize @_ @x)
83+
84+ gtoResult =
85+ G.gtoResultADT
86+ @TSerialize
87+ @TColumns
88+ @(Eval (ADTRep t Expr))
89+ @(Eval (ADTRep t Result))
90+ (\(_ :: proxy x) -> serialize @_ @x) .
91+ from .
92+ Record
93+
94+
95+type ADTable :: K.Rel8able -> Constraint
96+class
97+ ( Generic (Record (t Result))
98+ , HTable (GColumnsADT t)
99+ , G.GSerializeADT TSerialize TColumns (Eval (ADTRep t Expr)) (Eval (ADTRep t Result))
100+ )
101+ => ADTable t
102+instance
103+ ( Generic (Record (t Result))
104+ , HTable (GColumnsADT t)
105+ , G.GSerializeADT TSerialize TColumns (Eval (ADTRep t Expr)) (Eval (ADTRep t Result))
106+ )
107+ => ADTable t
108+
109+
110+type BuildableADT :: K.Rel8able -> Symbol -> Constraint
111+class GGBuildable 'K.Sum name (ADTRep t) => BuildableADT t name
112+instance GGBuildable 'K.Sum name (ADTRep t) => BuildableADT t name
113+
114+
115+type BuildADT :: K.Rel8able -> Symbol -> Type
116+type BuildADT t name = GGBuild 'K.Sum name (ADTRep t) (ADT t Expr)
117+
118+
119+buildADT :: forall t name. BuildableADT t name => BuildADT t name
120+buildADT =
121+ ggbuild @'K.Sum @name @(ADTRep t) @(ADT t Expr) ADT
122+
123+
124+type ConstructableADT :: K.Rel8able -> Constraint
125+class GGConstructable 'K.Sum (ADTRep t) => ConstructableADT t
126+instance GGConstructable 'K.Sum (ADTRep t) => ConstructableADT t
127+
128+
129+type ConstructADT :: K.Rel8able -> Type
130+type ConstructADT t = forall r. GGConstruct 'K.Sum (ADTRep t) r
131+
132+
133+constructADT :: forall t. ConstructableADT t => ConstructADT t -> ADT t Expr
134+constructADT f =
135+ ggconstruct @'K.Sum @(ADTRep t) @(ADT t Expr) ADT
136+ (f @(ADT t Expr))
137+
138+
139+type DeconstructADT :: K.Rel8able -> Type -> Type
140+type DeconstructADT t r = GGDeconstruct 'K.Sum (ADTRep t) (ADT t Expr) r
141+
142+
143+deconstructADT :: forall t r. (ConstructableADT t, Table Expr r)
144+ => DeconstructADT t r
145+deconstructADT =
146+ ggdeconstruct @'K.Sum @(ADTRep t) @(ADT t Expr) @r (\(ADT a) -> a)
147+
148+
149+type NameADT :: K.Rel8able -> Type
150+type NameADT t = GGName 'K.Sum (ADTRep t) (ADT t Name)
151+
152+
153+nameADT :: forall t. ConstructableADT t => NameADT t
154+nameADT = ggname @'K.Sum @(ADTRep t) @(ADT t Name) ADT
155+
156+
157+type AggregateADT :: K.Rel8able -> Type
158+type AggregateADT t = forall r. GGAggregate 'K.Sum (ADTRep t) r
159+
160+
161+aggregateADT :: forall t. ConstructableADT t
162+ => AggregateADT t -> ADT t Expr -> ADT t Aggregate
163+aggregateADT f =
164+ ggaggregate @'K.Sum @(ADTRep t) @(ADT t Expr) @(ADT t Aggregate) ADT (\(ADT a) -> a)
165+ (f @(ADT t Aggregate))
166+
167+
168+data ADTRep :: K.Rel8able -> K.Context -> Exp (Type -> Type)
169+type instance Eval (ADTRep t context) = GRep t context
170+
171+
172+type GColumnsADT :: K.Rel8able -> K.HTable
173+type GColumnsADT t = G.GColumnsADT TColumns (GRep t Expr)
src/Rel8/Table/Aggregate.hs+42−30
@@ -6,10 +6,8 @@
6{-# language ViewPatterns #-}
6{-# language ViewPatterns #-}
7
7
8module Rel8.Table.Aggregate
8module Rel8.Table.Aggregate
9− ( groupBy
9+ ( groupBy, hgroupBy
10− , listAgg
11− , nonEmptyAgg
10+ , listAgg, nonEmptyAgg
12− , runAggregation
13 )
11 )
14where
12where
15
13
@@ -18,31 +16,49 @@ import Data.Functor.Identity ( Identity( Identity ) )
18import Prelude
16import Prelude
19
17
20-- rel8
18-- rel8
21−import Rel8.Aggregate ( Aggregate )
19+import Rel8.Aggregate ( Aggregate, Aggregates )
22import Rel8.Expr ( Expr )
20import Rel8.Expr ( Expr )
23−import Rel8.Expr.Aggregate ( listAggExpr, nonEmptyAggExpr, sgroupByExpr )
21+import Rel8.Expr.Aggregate
24−import Rel8.Schema.Context ( Col'(..) )
22+ ( groupByExpr
23+ , slistAggExpr
24+ , snonEmptyAggExpr
25+ )
25import Rel8.Schema.Dict ( Dict( Dict ) )
26import Rel8.Schema.Dict ( Dict( Dict ) )
26−import Rel8.Schema.HTable ( htabulate, hfield, hdicts, hspecs )
27+import Rel8.Schema.HTable ( HTable, hfield, htabulate )
27import Rel8.Schema.HTable.Vectorize ( hvectorize )
28import Rel8.Schema.HTable.Vectorize ( hvectorize )
28−import Rel8.Schema.Spec ( SSpec(..) )
29+import Rel8.Schema.Null ( Sql )
29−import Rel8.Schema.Spec.ConstrainDBType ( ConstrainDBType )
30+import Rel8.Schema.Spec ( Spec( Spec, info ) )
30−import Rel8.Table ( Table, Columns, toColumns, fromColumns )
31+import Rel8.Table ( toColumns, fromColumns )
31−import Rel8.Table.Eq ( EqTable )
32+import Rel8.Table.Eq ( EqTable, eqTable )
32import Rel8.Table.List ( ListTable )
33import Rel8.Table.List ( ListTable )
33import Rel8.Table.NonEmpty ( NonEmptyTable )
34import Rel8.Table.NonEmpty ( NonEmptyTable )
34−import Rel8.Table.Recontextualize ( Aggregates )
35import Rel8.Type.Eq ( DBEq )
35import Rel8.Type.Eq ( DBEq )
36
36
37
37
38+-- | Group equal tables together. This works by aggregating each column in the
39+-- given table with 'groupByExpr'.
40+--
41+-- For example, if we have a table of items, we could group the items by the
42+-- order they belong to:
43+--
44+-- @
45+-- itemsByOrder :: Query (OrderId Expr, ListTable Expr (Item Expr))
46+-- itemsByOrder = aggregate $ do
47+-- item <- each itemSchema
48+-- let orderId = groupBy (itemOrderId item)
49+-- let orderItems = listAgg item
50+-- pure (orderId, orderItems)
51+-- @
38−groupBy :: forall exprs. EqTable exprs => exprs -> Aggregate exprs
52+groupBy :: forall exprs aggregates. (EqTable exprs, Aggregates aggregates exprs)
53+ => exprs -> aggregates
54+groupBy = fromColumns . hgroupBy (eqTable @exprs) . toColumns
55+
56+
57+hgroupBy :: HTable t => t (Dict (Sql DBEq)) -> t Expr -> t Aggregate
39−groupBy (toColumns -> exprs) = fromColumns $ htabulate $ \field ->
58+hgroupBy eqs exprs = htabulate $ \field ->
40− case hfield dicts field of
59+ case hfield eqs field of
41− Dict -> case hfield hspecs field of
60+ Dict -> case hfield exprs field of
42− SSpec {nullability} -> case hfield exprs field of
61+ expr -> groupByExpr expr
43− DB expr -> Aggregation $ sgroupByExpr nullability expr
44− where
45− dicts = hdicts @(Columns exprs) @(ConstrainDBType DBEq)
46
62
47
63
48-- | Aggregate rows into a single row containing an array of all aggregated
64-- | Aggregate rows into a single row containing an array of all aggregated
@@ -55,26 +71,22 @@ groupBy (toColumns -> exprs) = fromColumns $ htabulate $ \field ->
55-- items:
71-- items:
56--
72--
57-- @
73-- @
58−-- ordersWithItems :: Query (Order Expr, ListTable (Item Expr))
74+-- ordersWithItems :: Query (Order Expr, ListTable Expr (Item Expr))
59-- ordersWithItems = do
75-- ordersWithItems = do
60-- order <- each orderSchema
76-- order <- each orderSchema
61-- items <- aggregate $ listAgg <$> itemsFromOrder order
77-- items <- aggregate $ listAgg <$> itemsFromOrder order
62-- return (order, items)
78-- return (order, items)
63-- @
79-- @
64−listAgg :: Table Expr exprs => exprs -> Aggregate (ListTable exprs)
80+listAgg :: Aggregates aggregates exprs => exprs -> ListTable Aggregate aggregates
65listAgg (toColumns -> exprs) = fromColumns $
81listAgg (toColumns -> exprs) = fromColumns $
66 hvectorize
82 hvectorize
67− (\_ (Identity (DB a)) -> Aggregation $ listAggExpr a)
83+ (\Spec {info} (Identity a) -> slistAggExpr info a)
68 (pure exprs)
84 (pure exprs)
69
85
70
86
71-- | Like 'listAgg', but the result is guaranteed to be a non-empty list.
87-- | Like 'listAgg', but the result is guaranteed to be a non-empty list.
72−nonEmptyAgg :: Table Expr exprs => exprs -> Aggregate (NonEmptyTable exprs)
88+nonEmptyAgg :: Aggregates aggregates exprs => exprs -> NonEmptyTable Aggregate aggregates
73nonEmptyAgg (toColumns -> exprs) = fromColumns $
89nonEmptyAgg (toColumns -> exprs) = fromColumns $
74 hvectorize
90 hvectorize
75− (\_ (Identity (DB a)) -> Aggregation $ nonEmptyAggExpr a)
91+ (\Spec {info} (Identity a) -> snonEmptyAggExpr info a)
76 (pure exprs)
92 (pure exprs)
77−
78−
79−runAggregation :: Aggregates aggregates exprs => aggregates -> Aggregate exprs
80−runAggregation = fromColumns . toColumns
src/Rel8/Table/Alternative.hs+2−2
@@ -20,8 +20,8 @@ import Rel8.Table ( Table )
20-- | Like 'Alt' in Haskell. This class is purely a Rel8 concept, and allows you
20-- | Like 'Alt' in Haskell. This class is purely a Rel8 concept, and allows you
21-- to take a choice between two tables. See also 'AlternativeTable'.
21-- to take a choice between two tables. See also 'AlternativeTable'.
22--
22--
23−-- For example, using '<|>:' on 'MaybeTable' allows you to combine two tables
23+-- For example, using '<|>:' on 'Rel8.MaybeTable' allows you to combine two
24−-- and to return the first one that is a "just" MaybeTable.
24+-- tables and to return the first one that is a "just" MaybeTable.
25type AltTable :: (Type -> Type) -> Constraint
25type AltTable :: (Type -> Type) -> Constraint
26class AltTable f where
26class AltTable f where
27 -- | An associative binary operation on 'Table's.
27 -- | An associative binary operation on 'Table's.
src/Rel8/Table/Bool.hs+19−6
@@ -5,6 +5,7 @@
5module Rel8.Table.Bool
5module Rel8.Table.Bool
6 ( bool
6 ( bool
7 , case_
7 , case_
8+ , nullable
8 )
9 )
9where
10where
10
11
@@ -14,22 +15,34 @@ import Prelude
14-- rel8
15-- rel8
15import Rel8.Expr ( Expr )
16import Rel8.Expr ( Expr )
16import Rel8.Expr.Bool ( boolExpr, caseExpr )
17import Rel8.Expr.Bool ( boolExpr, caseExpr )
17−import Rel8.Schema.Context ( Col'(..) )
18+import Rel8.Expr.Null ( isNull, unsafeUnnullify )
18import Rel8.Schema.HTable ( htabulate, hfield )
19import Rel8.Schema.HTable ( htabulate, hfield )
19import Rel8.Table ( Table, fromColumns, toColumns )
20import Rel8.Table ( Table, fromColumns, toColumns )
20
21
21
22
23+-- | An if-then-else expression on tables.
24+--
25+-- @bool x y p@ returns @x@ if @p@ is @False@, and returns @y@ if @p@ is
26+-- @True@.
22bool :: Table Expr a => a -> a -> Expr Bool -> a
27bool :: Table Expr a => a -> a -> Expr Bool -> a
23bool (toColumns -> false) (toColumns -> true) condition =
28bool (toColumns -> false) (toColumns -> true) condition =
24 fromColumns $ htabulate $ \field ->
29 fromColumns $ htabulate $ \field ->
25 case (hfield false field, hfield true field) of
30 case (hfield false field, hfield true field) of
26− (DB falseExpr, DB trueExpr) ->
27− DB (boolExpr falseExpr trueExpr condition)
31+ (falseExpr, trueExpr) -> boolExpr falseExpr trueExpr condition
32+{-# INLINABLE bool #-}
28
33
29
34
35+-- | Produce a table expression from a list of alternatives. Returns the first
36+-- table where the @Expr Bool@ expression is @True@. If no alternatives are
37+-- true, the given default is returned.
30case_ :: Table Expr a => [(Expr Bool, a)] -> a -> a
38case_ :: Table Expr a => [(Expr Bool, a)] -> a -> a
31case_ (map (fmap toColumns) -> branches) (toColumns -> fallback) =
39case_ (map (fmap toColumns) -> branches) (toColumns -> fallback) =
32 fromColumns $ htabulate $ \field -> case hfield fallback field of
40 fromColumns $ htabulate $ \field -> case hfield fallback field of
33− DB fallbackExpr ->
41+ fallbackExpr ->
34− case map (fmap (unDB . (`hfield` field))) branches of
42+ case map (fmap (`hfield` field)) branches of
35− branchExprs -> DB (caseExpr branchExprs fallbackExpr)
43+ branchExprs -> caseExpr branchExprs fallbackExpr
44+
45+
46+-- | Like 'maybe', but to eliminate @null@.
47+nullable :: Table Expr b => b -> (Expr a -> b) -> Expr (Maybe a) -> b
48+nullable b f ma = bool (f (unsafeUnnullify ma)) b (isNull ma)
src/Rel8/Table/Cols.hsnew file+50
@@ -0,0 +1,50 @@
1+{-# language DataKinds #-}
2+{-# language FlexibleInstances #-}
3+{-# language MultiParamTypeClasses #-}
4+{-# language StandaloneKindSignatures #-}
5+{-# language TypeFamilies #-}
6+{-# language UndecidableInstances #-}
7+
8+module Rel8.Table.Cols
9+ ( Cols( Cols )
10+ , fromCols
11+ , toCols
12+ )
13+where
14+
15+-- base
16+import Data.Kind ( Type )
17+import Prelude
18+
19+-- rel8
20+import qualified Rel8.Schema.Kind as K
21+import Rel8.Schema.HTable ( HTable )
22+import Rel8.Schema.Result ( Result )
23+import Rel8.Table ( Table(..) )
24+
25+
26+type Cols :: K.Context -> K.HTable -> Type
27+newtype Cols context columns = Cols (columns context)
28+
29+
30+instance (HTable columns, context ~ context') =>
31+ Table context' (Cols context columns)
32+ where
33+ type Columns (Cols context columns) = columns
34+ type Context (Cols context columns) = context
35+ type FromExprs (Cols context columns) = Cols Result columns
36+ type Transpose to (Cols context columns) = Cols to columns
37+
38+ toColumns (Cols a) = a
39+ fromColumns = Cols
40+
41+ toResult (Cols a) = a
42+ fromResult = Cols
43+
44+
45+fromCols :: Table context a => Cols context (Columns a) -> a
46+fromCols (Cols a) = fromColumns a
47+
48+
49+toCols :: Table context a => a -> Cols context (Columns a)
50+toCols = Cols . toColumns
src/Rel8/Table/Either.hs+161−91
@@ -3,45 +3,59 @@
3{-# language DerivingStrategies #-}
3{-# language DerivingStrategies #-}
4{-# language FlexibleContexts #-}
4{-# language FlexibleContexts #-}
5{-# language FlexibleInstances #-}
5{-# language FlexibleInstances #-}
6+{-# language LambdaCase #-}
6{-# language MultiParamTypeClasses #-}
7{-# language MultiParamTypeClasses #-}
7{-# language NamedFieldPuns #-}
8{-# language NamedFieldPuns #-}
9+{-# language ScopedTypeVariables #-}
8{-# language StandaloneKindSignatures #-}
10{-# language StandaloneKindSignatures #-}
11+{-# language TypeApplications #-}
9{-# language TypeFamilies #-}
12{-# language TypeFamilies #-}
10{-# language UndecidableInstances #-}
13{-# language UndecidableInstances #-}
11
14
15+{-# options_ghc -fno-warn-orphans #-}
16+
12module Rel8.Table.Either
17module Rel8.Table.Either
13 ( EitherTable(..)
18 ( EitherTable(..)
14 , eitherTable, leftTable, rightTable
19 , eitherTable, leftTable, rightTable
15 , isLeftTable, isRightTable
20 , isLeftTable, isRightTable
21+ , aggregateEitherTable
22+ , nameEitherTable
16 )
23 )
17where
24where
18
25
19-- base
26-- base
20import Data.Bifunctor ( Bifunctor, bimap )
27import Data.Bifunctor ( Bifunctor, bimap )
21−import Data.Functor.Identity ( runIdentity )
28+import Data.Functor.Identity ( Identity( Identity ) )
22import Data.Kind ( Type )
29import Data.Kind ( Type )
23import Prelude hiding ( undefined )
30import Prelude hiding ( undefined )
24
31
32+-- comonad
33+import Control.Comonad ( extract )
34+
25-- rel8
35-- rel8
36+import Rel8.Aggregate ( Aggregate )
26import Rel8.Expr ( Expr )
37import Rel8.Expr ( Expr )
38+import Rel8.Expr.Aggregate ( groupByExpr )
27import Rel8.Expr.Serialize ( litExpr )
39import Rel8.Expr.Serialize ( litExpr )
28−import Rel8.Schema.Context.Label ( Labelable, labeler, unlabeler )
40+import Rel8.Kind.Context ( Reifiable )
29−import Rel8.Schema.Context.Nullify
41+import Rel8.Schema.Context.Nullify ( Nullifiable )
30− ( Nullifiable, NullifiableEq
42+import Rel8.Schema.Dict ( Dict( Dict ) )
31− , encodeTag, decodeTag
32− , nullifier, unnullifier
33− )
34import Rel8.Schema.HTable.Either ( HEitherTable(..) )
43import Rel8.Schema.HTable.Either ( HEitherTable(..) )
35import Rel8.Schema.HTable.Identity ( HIdentity(..) )
44import Rel8.Schema.HTable.Identity ( HIdentity(..) )
36−import Rel8.Schema.HTable.Label ( HLabel, hlabel, hunlabel )
45+import Rel8.Schema.HTable.Label ( hlabel, hunlabel )
37−import Rel8.Schema.HTable.Nullify ( hnullify, hunnullify )
46+import qualified Rel8.Schema.Kind as K
47+import Rel8.Schema.Name ( Name )
48+import Rel8.Table
38−import Rel8.Table ( Table, Columns, Context, fromColumns, toColumns )
49+ ( Table, Columns, Context, fromColumns, toColumns
39−import Rel8.Table.Bool ( bool )
50+ , FromExprs, fromResult, toResult
40−import Rel8.Table.Lifted
51+ , Transpose
41− ( Table1, Columns1, ConstrainContext1, fromColumns1, toColumns1
42− , Table2, Columns2, ConstrainContext2, fromColumns2, toColumns2
43 )
52 )
44−import Rel8.Table.Recontextualize ( Recontextualize )
53+import Rel8.Table.Bool ( bool )
54+import Rel8.Table.Eq ( EqTable, eqTable )
55+import Rel8.Table.Nullify ( Nullify, aggregateNullify, guard )
56+import Rel8.Table.Ord ( OrdTable, ordTable )
57+import Rel8.Table.Projection ( Biprojectable, Projectable, biproject, project )
58+import Rel8.Table.Serialize ( ToExprs )
45import Rel8.Table.Undefined ( undefined )
59import Rel8.Table.Undefined ( undefined )
46import Rel8.Type.Tag ( EitherTag( IsLeft, IsRight ), isLeft, isRight )
60import Rel8.Type.Tag ( EitherTag( IsLeft, IsRight ), isLeft, isRight )
47
61
@@ -50,124 +64,180 @@ import Data.Functor.Apply ( Apply, (<.>) )
50import Data.Functor.Bind ( Bind, (>>-) )
64import Data.Functor.Bind ( Bind, (>>-) )
51
65
52
66
67+-- | An @EitherTable a b@ is a Rel8 table that contains either the table @a@ or
68+-- the table @b@. You can construct an @EitherTable@ using 'leftTable' and
69+-- 'rightTable', and eliminate/pattern match using 'eitherTable'.
70+--
71+-- An @EitherTable@ is operationally the same as Haskell's 'Either' type, but
72+-- adapted to work with Rel8.
53−type EitherTable :: Type -> Type -> Type
73+type EitherTable :: K.Context -> Type -> Type -> Type
54−data EitherTable a b = EitherTable
74+data EitherTable context a b = EitherTable
55− { tag :: Expr EitherTag
75+ { tag :: context EitherTag
56− , left :: a
76+ , left :: Nullify context a
57− , right :: b
77+ , right :: Nullify context b
58 }
78 }
59− deriving stock (Show, Functor)
79+ deriving stock Functor
80+
81+
82+instance Biprojectable (EitherTable context) where
83+ biproject f g (EitherTable tag a b) =
84+ EitherTable tag (project f a) (project g b)
85+
86+
87+instance Nullifiable context => Bifunctor (EitherTable context) where
88+ bimap f g (EitherTable tag a b) = EitherTable tag (fmap f a) (fmap g b)
60
89
61
90
62−instance Bifunctor EitherTable where
91+instance Projectable (EitherTable context a) where
63− bimap f g (EitherTable tag a b) = EitherTable tag (f a) (g b)
92+ project f (EitherTable tag a b) = EitherTable tag a (project f b)
64
93
65
94
66−instance Table Expr a => Apply (EitherTable a) where
95+instance (context ~ Expr, Table Expr a) => Apply (EitherTable context a) where
67 EitherTable tag l1 f <.> EitherTable tag' l2 a =
96 EitherTable tag l1 f <.> EitherTable tag' l2 a =
68− EitherTable (tag <> tag') (bool l1 l2 (isLeft tag)) (f a)
97+ EitherTable (tag <> tag') (bool l1 l2 (isLeft tag)) (f <.> a)
69
98
70
99
71−instance Table Expr a => Applicative (EitherTable a) where
100+instance (context ~ Expr, Table Expr a) => Applicative (EitherTable context a) where
72 pure = rightTable
101 pure = rightTable
73 (<*>) = (<.>)
102 (<*>) = (<.>)
74
103
75
104
76−instance Table Expr a => Bind (EitherTable a) where
105+instance (context ~ Expr, Table Expr a) => Bind (EitherTable context a) where
77− EitherTable tag l1 a >>- f = case f a of
106+ EitherTable tag l1 a >>- f = case f (extract a) of
78 EitherTable tag' l2 b ->
107 EitherTable tag' l2 b ->
79 EitherTable (tag <> tag') (bool l1 l2 (isRight tag)) b
108 EitherTable (tag <> tag') (bool l1 l2 (isRight tag)) b
80
109
81
110
82−instance Table Expr a => Monad (EitherTable a) where
111+instance (context ~ Expr, Table Expr a) => Monad (EitherTable context a) where
83 (>>=) = (>>-)
112 (>>=) = (>>-)
84
113
85
114
86−instance (Table Expr a, Table Expr b) => Semigroup (EitherTable a b) where
115+instance (context ~ Expr, Table Expr a, Table Expr b) =>
116+ Semigroup (EitherTable context a b)
117+ where
87 a <> b = bool a b (isRightTable a)
118 a <> b = bool a b (isRightTable a)
88
119
89
120
90−instance Table2 EitherTable where
121+instance
122+ ( Table context a, Table context b
123+ , Reifiable context, context ~ context'
124+ )
125+ => Table context' (EitherTable context a b)
126+ where
91− type Columns2 EitherTable = HEitherTable
127+ type Columns (EitherTable context a b) = HEitherTable (Columns a) (Columns b)
92− type ConstrainContext2 EitherTable = Nullifiable
128+ type Context (EitherTable context a b) = Context a
129+ type FromExprs (EitherTable context a b) = Either (FromExprs a) (FromExprs b)
130+ type Transpose to (EitherTable context a b) =
131+ EitherTable to (Transpose to a) (Transpose to b)
132+
133+ toColumns EitherTable {tag, left, right} = HEitherTable
134+ { htag = hlabel $ HIdentity tag
135+ , hleft = hlabel $ guard tag (== IsLeft) isLeft $ toColumns left
136+ , hright = hlabel $ guard tag (== IsRight) isRight $ toColumns right
137+ }
93
138
94− toColumns2 f g EitherTable {tag, left, right} = HEitherTable
139+ fromColumns HEitherTable {htag, hleft, hright} = EitherTable
95− { htag
140+ { tag = unHIdentity $ hunlabel htag
96− , hleft = hnullify (nullifier (isLeft tag)) $ f left
141+ , left = fromColumns $ hunlabel hleft
97− , hright = hnullify (nullifier (isRight tag)) $ g right
142+ , right = fromColumns $ hunlabel hright
98 }
143 }
99− where
100− htag = HIdentity (encodeTag tag)
101−
102− fromColumns2 f g HEitherTable {htag = htag, hleft, hright} =
103− EitherTable
104− { tag
105− , left = f $ runIdentity $
106− hunnullify (\a -> pure . unnullifier (isLeft tag) a) hleft
107− , right = g $ runIdentity $
108− hunnullify (\a -> pure . unnullifier (isRight tag) a) hright
109− }
110− where
111− tag = decodeTag $ unHIdentity htag
112
144
113− {-# INLINABLE fromColumns2 #-}
145+ toResult = \case
114− {-# INLINABLE toColumns2 #-}
146+ Left table -> HEitherTable
147+ { htag = hlabel (HIdentity (Identity IsLeft))
148+ , hleft = hlabel (toResult @_ @(Nullify context a) (Just table))
149+ , hright = hlabel (toResult @_ @(Nullify context b) Nothing)
150+ }
151+ Right table -> HEitherTable
152+ { htag = hlabel (HIdentity (Identity IsRight))
153+ , hleft = hlabel (toResult @_ @(Nullify context a) Nothing)
154+ , hright = hlabel (toResult @_ @(Nullify context b) (Just table))
155+ }
115
156
157+ fromResult HEitherTable {htag, hleft, hright} = case hunlabel htag of
158+ HIdentity (Identity tag) -> case tag of
159+ IsLeft -> maybe err Left $ fromResult @_ @(Nullify context a) (hunlabel hleft)
160+ IsRight -> maybe err Right $ fromResult @_ @(Nullify context b) (hunlabel hright)
161+ where
162+ err = error "Either.fromColumns: mismatch between tag and data"
116
163
117−instance Table context a => Table1 (EitherTable a) where
118− type Columns1 (EitherTable a) = HEitherTable (Columns a)
119− type ConstrainContext1 (EitherTable a) = NullifiableEq (Context a)
120
164
121− toColumns1 = toColumns2 toColumns
165+instance (EqTable a, EqTable b, context ~ Expr) =>
122− fromColumns1 = fromColumns2 fromColumns
166+ EqTable (EitherTable context a b)
167+ where
168+ eqTable = HEitherTable
169+ { htag = hlabel (HIdentity Dict)
170+ , hleft = hlabel (eqTable @(Nullify context a))
171+ , hright = hlabel (eqTable @(Nullify context b))
172+ }
123
173
124
174
125−instance
175+instance (OrdTable a, OrdTable b, context ~ Expr) =>
126− ( Table context a, Table context b
127− , Labelable context, Nullifiable context
128− ) =>
129− Table context (EitherTable a b)
176+ OrdTable (EitherTable context a b)
130 where
177 where
131− type Columns (EitherTable a b) =
178+ ordTable = HEitherTable
132− HEitherTable (HLabel "Left" (Columns a)) (HLabel "Right" (Columns b))
179+ { htag = hlabel (HIdentity Dict)
133− type Context (EitherTable a b) = Context a
180+ , hleft = hlabel (ordTable @(Nullify context a))
134−
181+ , hright = hlabel (ordTable @(Nullify context b))
135− toColumns =
182+ }
136− toColumns2
137− (hlabel labeler . toColumns)
138− (hlabel labeler . toColumns)
139− fromColumns =
140− fromColumns2
141− (fromColumns . hunlabel unlabeler)
142− (fromColumns . hunlabel unlabeler)
143
183
144
184
145−instance
185+instance (ToExprs exprs1 a, ToExprs exprs2 b, x ~ EitherTable Expr exprs1 exprs2) =>
146− ( Nullifiable from, Labelable from
186+ ToExprs x (Either a b)
147− , Nullifiable to, Labelable to
148− , Recontextualize from to a1 b1
149− , Recontextualize from to a2 b2
150− ) =>
151− Recontextualize from to (EitherTable a1 a2) (EitherTable b1 b2)
152
187
153
188
189+-- | Test if an 'EitherTable' is a 'leftTable'.
154−isLeftTable :: EitherTable a b -> Expr Bool
190+isLeftTable :: EitherTable Expr a b -> Expr Bool
155−isLeftTable = isLeft . tag
191+isLeftTable EitherTable {tag} = isLeft tag
156
192
157
193
194+-- | Test if an 'EitherTable' is a 'rightTable'.
158−isRightTable :: EitherTable a b -> Expr Bool
195+isRightTable :: EitherTable Expr a b -> Expr Bool
159−isRightTable = isRight . tag
196+isRightTable EitherTable {tag} = isRight tag
160
197
161
198
199+-- | Pattern match/eliminate an 'EitherTable', by providing mappings from a
200+-- 'leftTable' and 'rightTable'.
162eitherTable :: Table Expr c
201eitherTable :: Table Expr c
163− => (a -> c) -> (b -> c) -> EitherTable a b -> c
202+ => (a -> c) -> (b -> c) -> EitherTable Expr a b -> c
164eitherTable f g EitherTable {tag, left, right} =
203eitherTable f g EitherTable {tag, left, right} =
165− bool (f left) (g right) (isRight tag)
204+ bool (f (extract left)) (g (extract right)) (isRight tag)
205+
166
206
207+-- | Construct a left 'EitherTable'. Like 'Left'.
208+leftTable :: Table Expr b => a -> EitherTable Expr a b
209+leftTable a = EitherTable (litExpr IsLeft) (pure a) undefined
167
210
211+
212+-- | Construct a right 'EitherTable'. Like 'Right'.
168−leftTable :: Table Expr b => a -> EitherTable a b
213+rightTable :: Table Expr a => b -> EitherTable Expr a b
169−leftTable a = EitherTable (litExpr IsLeft) a undefined
214+rightTable = EitherTable (litExpr IsRight) undefined . pure
215+
216+
217+-- | Lift a pair of aggregating functions to operate on an 'EitherTable'.
218+-- @leftTable@s and @rightTable@s are grouped separately.
219+aggregateEitherTable :: ()
220+ => (exprs -> aggregates)
221+ -> (exprs' -> aggregates')
222+ -> EitherTable Expr exprs exprs'
223+ -> EitherTable Aggregate aggregates aggregates'
224+aggregateEitherTable f g (EitherTable tag a b) = EitherTable
225+ { tag = groupByExpr tag
226+ , left = aggregateNullify f a
227+ , right = aggregateNullify g b
228+ }
170
229
171
230
231+-- | Construct a 'EitherTable' in the 'Name' context. This can be useful if you
232+-- have a 'EitherTable' that you are storing in a table and need to construct a
233+-- 'TableSchema'.
234+nameEitherTable
235+ :: Name EitherTag
236+ -- ^ The name of the column to track whether a row is a 'leftTable' or
237+ -- 'rightTable'.
238+ -> a
239+ -- ^ Names of the columns in the @a@ table.
240+ -> b
241+ -- ^ Names of the columns in the @b@ table.
172−rightTable :: Table Expr a => b -> EitherTable a b
242+ -> EitherTable Name a b
173−rightTable = EitherTable (litExpr IsRight) undefined
243+nameEitherTable tag left right = EitherTable tag (pure left) (pure right)
src/Rel8/Table/Eq.hs+65−35
@@ -1,17 +1,20 @@
1+{-# language AllowAmbiguousTypes #-}
2+{-# language BlockArguments #-}
1{-# language DataKinds #-}
3{-# language DataKinds #-}
4+{-# language DefaultSignatures #-}
5+{-# language DisambiguateRecordFields #-}
2{-# language FlexibleContexts #-}
6{-# language FlexibleContexts #-}
3{-# language FlexibleInstances #-}
7{-# language FlexibleInstances #-}
4−{-# language NamedFieldPuns #-}
5{-# language ScopedTypeVariables #-}
8{-# language ScopedTypeVariables #-}
6{-# language StandaloneKindSignatures #-}
9{-# language StandaloneKindSignatures #-}
7{-# language TypeApplications #-}
10{-# language TypeApplications #-}
8{-# language TypeFamilies #-}
11{-# language TypeFamilies #-}
12+{-# language TypeOperators #-}
9{-# language UndecidableInstances #-}
13{-# language UndecidableInstances #-}
10−{-# language UndecidableSuperClasses #-}
11{-# language ViewPatterns #-}
14{-# language ViewPatterns #-}
12
15
13module Rel8.Table.Eq
16module Rel8.Table.Eq
14− ( EqTable, (==:), (/=:)
17+ ( EqTable( eqTable ), (==:), (/=:)
15 )
18 )
16where
19where
17
20
@@ -20,36 +23,71 @@ import Data.Foldable ( foldl' )
20import Data.Functor.Const ( Const( Const ), getConst )
23import Data.Functor.Const ( Const( Const ), getConst )
21import Data.Kind ( Constraint, Type )
24import Data.Kind ( Constraint, Type )
22import Data.List.NonEmpty ( NonEmpty( (:|) ) )
25import Data.List.NonEmpty ( NonEmpty( (:|) ) )
23−import Prelude hiding ( seq )
26+import GHC.Generics ( Rep )
27+import Prelude
24
28
25-- rel8
29-- rel8
26import Rel8.Expr ( Expr )
30import Rel8.Expr ( Expr )
27import Rel8.Expr.Bool ( (||.), (&&.) )
31import Rel8.Expr.Bool ( (||.), (&&.) )
28−import Rel8.Expr.Eq ( seq, sne )
32+import Rel8.Expr.Eq ( (==.), (/=.) )
29−import Rel8.Opaque ( Opaque )
33+import Rel8.FCF ( Eval, Exp )
30−import Rel8.Schema.Context ( Col'(..) )
34+import Rel8.Generic.Record ( Record )
35+import Rel8.Generic.Table.Record ( GTable, GColumns, gtable )
31import Rel8.Schema.Dict ( Dict( Dict ) )
36import Rel8.Schema.Dict ( Dict( Dict ) )
32−import Rel8.Schema.HTable
37+import Rel8.Schema.HTable ( htabulateA, hfield )
33− ( HConstrainTable
34− , htabulateA, hfield
35− , hdicts, hspecs
36− )
37−import Rel8.Schema.Spec ( SSpec(..) )
38+import Rel8.Schema.HTable.Identity ( HIdentity( HIdentity ) )
38−import Rel8.Schema.Spec.ConstrainDBType ( ConstrainDBType )
39+import Rel8.Schema.Null ( Sql )
39−import Rel8.Table ( Table, Columns, toColumns )
40+import Rel8.Table ( Table, Columns, toColumns, TColumns )
40import Rel8.Type.Eq ( DBEq )
41import Rel8.Type.Eq ( DBEq )
41
42
42
43
44+-- | The class of 'Table's that can be compared for equality. Equality on
45+-- tables is defined by equality of all columns all columns, so this class
46+-- means "all columns in a 'Table' have an instance of 'DBEq'".
43type EqTable :: Type -> Constraint
47type EqTable :: Type -> Constraint
44−class
45− ( Table Expr a
48+class Table Expr a => EqTable a where
46− , HConstrainTable (Columns a) (ConstrainDBType DBEq)
49+ eqTable :: Columns a (Dict (Sql DBEq))
47− ) => EqTable a
50+
51+ default eqTable ::
52+ ( GTable TEqTable TColumns (Rep (Record a))
53+ , Columns a ~ GColumns TColumns (Rep (Record a))
54+ )
55+ => Columns a (Dict (Sql DBEq))
56+ eqTable = gtable @TEqTable @TColumns @(Rep (Record a)) table
57+ where
58+ table (_ :: proxy x) = eqTable @x
59+
60+
61+data TEqTable :: Type -> Exp Constraint
62+type instance Eval (TEqTable a) = EqTable a
63+
64+
65+instance Sql DBEq a => EqTable (Expr a) where
66+ eqTable = HIdentity Dict
67+
68+
69+instance (EqTable a, EqTable b) => EqTable (a, b)
70+
71+
72+instance (EqTable a, EqTable b, EqTable c) => EqTable (a, b, c)
73+
74+
75+instance (EqTable a, EqTable b, EqTable c, EqTable d) => EqTable (a, b, c, d)
76+
77+
78+instance (EqTable a, EqTable b, EqTable c, EqTable d, EqTable e) =>
79+ EqTable (a, b, c, d, e)
80+
81+
82+instance (EqTable a, EqTable b, EqTable c, EqTable d, EqTable e, EqTable f) =>
83+ EqTable (a, b, c, d, e, f)
84+
85+
48instance
86instance
49− ( Table Expr a
87+ ( EqTable a, EqTable b, EqTable c, EqTable d, EqTable e, EqTable f
50− , HConstrainTable (Columns a) (ConstrainDBType DBEq)
88+ , EqTable g
89+ )
51− ) => EqTable a
90+ => EqTable (a, b, c, d, e, f, g)
52−instance {-# OVERLAPPING #-} EqTable Opaque
53
91
54
92
55-- | Compare two 'Table's for equality. This corresponds to comparing all
93-- | Compare two 'Table's for equality. This corresponds to comparing all
@@ -59,12 +97,8 @@ instance {-# OVERLAPPING #-} EqTable Opaque
59(toColumns -> as) ==: (toColumns -> bs) =
97(toColumns -> as) ==: (toColumns -> bs) =
60 foldl1' (&&.) $ getConst $ htabulateA $ \field ->
98 foldl1' (&&.) $ getConst $ htabulateA $ \field ->
61 case (hfield as field, hfield bs field) of
99 case (hfield as field, hfield bs field) of
62− (DB a, DB b) -> case hfield dicts field of
100+ (a, b) -> case hfield (eqTable @a) field of
63− Dict -> case hfield specs field of
101+ Dict -> Const (pure (a ==. b))
64− SSpec {nullability} -> Const (pure (seq nullability a b))
65− where
66− dicts = hdicts @(Columns a) @(ConstrainDBType DBEq)
67− specs = hspecs @(Columns a)
68infix 4 ==:
102infix 4 ==:
69
103
70
104
@@ -75,12 +109,8 @@ infix 4 ==:
75(toColumns -> as) /=: (toColumns -> bs) =
109(toColumns -> as) /=: (toColumns -> bs) =
76 foldl1' (||.) $ getConst $ htabulateA $ \field ->
110 foldl1' (||.) $ getConst $ htabulateA $ \field ->
77 case (hfield as field, hfield bs field) of
111 case (hfield as field, hfield bs field) of
78− (DB a, DB b) -> case hfield dicts field of
112+ (a, b) -> case hfield (eqTable @a) field of
79− Dict -> case hfield specs field of
113+ Dict -> Const (pure (a /=. b))
80− SSpec {nullability} -> Const (pure (sne nullability a b))
81− where
82− dicts = hdicts @(Columns a) @(ConstrainDBType DBEq)
83− specs = hspecs @(Columns a)
84infix 4 /=:
114infix 4 /=:
85
115
86
116
src/Rel8/Table/HKD.hsnew file+228
@@ -0,0 +1,228 @@
1+{-# language AllowAmbiguousTypes #-}
2+{-# language DataKinds #-}
3+{-# language FlexibleContexts #-}
4+{-# language FlexibleInstances #-}
5+{-# language MultiParamTypeClasses #-}
6+{-# language RankNTypes #-}
7+{-# language ScopedTypeVariables #-}
8+{-# language StandaloneKindSignatures #-}
9+{-# language TypeApplications #-}
10+{-# language TypeFamilies #-}
11+{-# language UndecidableInstances #-}
12+{-# language UndecidableSuperClasses #-}
13+
14+module Rel8.Table.HKD
15+ ( HKD( HKD )
16+ , HKDable
17+ , BuildableHKD
18+ , BuildHKD, buildHKD
19+ , ConstructableHKD
20+ , ConstructHKD, constructHKD
21+ , DeconstructHKD, deconstructHKD
22+ , NameHKD, nameHKD
23+ , AggregateHKD, aggregateHKD
24+ , HKDRep
25+ )
26+where
27+
28+-- base
29+import Data.Kind ( Constraint, Type )
30+import GHC.Generics ( Generic, Rep, from, to )
31+import GHC.TypeLits ( Symbol )
32+import Prelude
33+
34+-- rel8
35+import Rel8.Aggregate ( Aggregate )
36+import Rel8.Column ( TColumn )
37+import Rel8.Expr ( Expr )
38+import Rel8.FCF ( Eval, Exp )
39+import Rel8.Kind.Algebra ( KnownAlgebra )
40+import Rel8.Generic.Construction
41+ ( GGBuildable
42+ , GGBuild, ggbuild
43+ , GGConstructable
44+ , GGConstruct, ggconstruct
45+ , GGDeconstruct, ggdeconstruct
46+ , GGName, ggname
47+ , GGAggregate, ggaggregate
48+ )
49+import Rel8.Generic.Map ( GMap )
50+import Rel8.Generic.Record
51+ ( GRecord, GRecordable, grecord, gunrecord
52+ , Record( Record ), unrecord
53+ )
54+import Rel8.Generic.Rel8able
55+ ( Rel8able
56+ , GColumns, gfromColumns, gtoColumns
57+ , GFromExprs, gfromResult, gtoResult
58+ )
59+import Rel8.Generic.Table
60+ ( GGSerialize, GGColumns, GAlgebra, ggfromResult, ggtoResult
61+ )
62+import Rel8.Generic.Table.Record ( GTable, GContext )
63+import qualified Rel8.Generic.Table.Record as G
64+import qualified Rel8.Schema.Kind as K
65+import Rel8.Schema.HTable ( HTable )
66+import Rel8.Schema.Name ( Name )
67+import Rel8.Schema.Result ( Result )
68+import Rel8.Table
69+ ( Table, fromColumns, toColumns, fromResult, toResult
70+ , TTable, TColumns, TContext
71+ , TSerialize
72+ )
73+
74+
75+type GColumnsHKD :: Type -> K.HTable
76+type GColumnsHKD a =
77+ Eval (GGColumns (GAlgebra (Rep a)) TColumns (GRecord (GMap (TColumn Expr) (Rep a))))
78+
79+
80+type HKD :: Type -> K.Rel8able
81+newtype HKD a f = HKD (GColumnsHKD a f)
82+
83+
84+instance HKDable a => Rel8able (HKD a) where
85+ type GColumns (HKD a) = GColumnsHKD a
86+ type GFromExprs (HKD a) = a
87+
88+ gfromColumns _ = HKD
89+ gtoColumns _ (HKD a) = a
90+
91+ gfromResult =
92+ unrecord .
93+ to .
94+ ggfromResult
95+ @(GAlgebra (Rep a))
96+ @TSerialize
97+ @TColumns
98+ @(Eval (HKDRep a Expr))
99+ @(Eval (HKDRep a Result))
100+ (\(_ :: proxy x) -> fromResult @_ @x)
101+
102+ gtoResult =
103+ ggtoResult
104+ @(GAlgebra (Rep a))
105+ @TSerialize
106+ @TColumns
107+ @(Eval (HKDRep a Expr))
108+ @(Eval (HKDRep a Result))
109+ (\(_ :: proxy x) -> toResult @_ @x) .
110+ from .
111+ Record
112+
113+
114+instance
115+ ( GTable (TTable f) TColumns (GRecord (GMap (TColumn f) (Rep a)))
116+ , G.GColumns TColumns (GRecord (GMap (TColumn f) (Rep a))) ~ GColumnsHKD a
117+ , GContext TContext (GRecord (GMap (TColumn f) (Rep a))) ~ f
118+ , GRecordable (GMap (TColumn f) (Rep a))
119+ )
120+ => Generic (HKD a f)
121+ where
122+ type Rep (HKD a f) = GMap (TColumn f) (Rep a)
123+
124+ from =
125+ gunrecord @(GMap (TColumn f) (Rep a)) .
126+ G.gfromColumns
127+ @(TTable f)
128+ @TColumns
129+ fromColumns .
130+ (\(HKD a) -> a)
131+
132+ to =
133+ HKD .
134+ G.gtoColumns
135+ @(TTable f)
136+ @TColumns
137+ toColumns .
138+ grecord @(GMap (TColumn f) (Rep a))
139+
140+
141+type HKDable :: Type -> Constraint
142+class
143+ ( Generic (Record a)
144+ , HTable (GColumns (HKD a))
145+ , KnownAlgebra (GAlgebra (Rep a))
146+ , Eval (GGSerialize (GAlgebra (Rep a)) TSerialize TColumns (Eval (HKDRep a Expr)) (Eval (HKDRep a Result)))
147+ , GRecord (GMap (TColumn Result) (Rep a)) ~ Rep (Record a)
148+ )
149+ => HKDable a
150+instance
151+ ( Generic (Record a)
152+ , HTable (GColumns (HKD a))
153+ , KnownAlgebra (GAlgebra (Rep a))
154+ , Eval (GGSerialize (GAlgebra (Rep a)) TSerialize TColumns (Eval (HKDRep a Expr)) (Eval (HKDRep a Result)))
155+ , GRecord (GMap (TColumn Result) (Rep a)) ~ Rep (Record a)
156+ )
157+ => HKDable a
158+
159+
160+type Top_ :: Constraint
161+class Top_
162+instance Top_
163+
164+
165+data Top :: Type -> Exp Constraint
166+type instance Eval (Top _) = Top_
167+
168+
169+type BuildableHKD :: Type -> Symbol -> Constraint
170+class GGBuildable (GAlgebra (Rep a)) name (HKDRep a) => BuildableHKD a name
171+instance GGBuildable (GAlgebra (Rep a)) name (HKDRep a) => BuildableHKD a name
172+
173+
174+type BuildHKD :: Type -> Symbol -> Type
175+type BuildHKD a name = GGBuild (GAlgebra (Rep a)) name (HKDRep a) (HKD a Expr)
176+
177+
178+buildHKD :: forall a name. BuildableHKD a name => BuildHKD a name
179+buildHKD =
180+ ggbuild @(GAlgebra (Rep a)) @name @(HKDRep a) @(HKD a Expr) HKD
181+
182+
183+type ConstructableHKD :: Type -> Constraint
184+class GGConstructable (GAlgebra (Rep a)) (HKDRep a) => ConstructableHKD a
185+instance GGConstructable (GAlgebra (Rep a)) (HKDRep a) => ConstructableHKD a
186+
187+
188+type ConstructHKD :: Type -> Type
189+type ConstructHKD a = forall r. GGConstruct (GAlgebra (Rep a)) (HKDRep a) r
190+
191+
192+constructHKD :: forall a. ConstructableHKD a => ConstructHKD a -> HKD a Expr
193+constructHKD f =
194+ ggconstruct @(GAlgebra (Rep a)) @(HKDRep a) @(HKD a Expr) HKD
195+ (f @(HKD a Expr))
196+
197+
198+type DeconstructHKD :: Type -> Type -> Type
199+type DeconstructHKD a r = GGDeconstruct (GAlgebra (Rep a)) (HKDRep a) (HKD a Expr) r
200+
201+
202+deconstructHKD :: forall a r. (ConstructableHKD a, Table Expr r)
203+ => DeconstructHKD a r
204+deconstructHKD = ggdeconstruct @(GAlgebra (Rep a)) @(HKDRep a) @(HKD a Expr) @r (\(HKD a) -> a)
205+
206+
207+type NameHKD :: Type -> Type
208+type NameHKD a = GGName (GAlgebra (Rep a)) (HKDRep a) (HKD a Name)
209+
210+
211+nameHKD :: forall a. ConstructableHKD a => NameHKD a
212+nameHKD = ggname @(GAlgebra (Rep a)) @(HKDRep a) @(HKD a Name) HKD
213+
214+
215+type AggregateHKD :: Type -> Type
216+type AggregateHKD a = forall r. GGAggregate (GAlgebra (Rep a)) (HKDRep a) r
217+
218+
219+aggregateHKD :: forall a. ConstructableHKD a
220+ => AggregateHKD a -> HKD a Expr -> HKD a Aggregate
221+aggregateHKD f =
222+ ggaggregate @(GAlgebra (Rep a)) @(HKDRep a) @(HKD a Expr) @(HKD a Aggregate) HKD (\(HKD a) -> a)
223+ (f @(HKD a Aggregate))
224+
225+
226+data HKDRep :: Type -> K.Context -> Exp (Type -> Type)
227+type instance Eval (HKDRep a context) =
228+ GRecord (GMap (TColumn context) (Rep a))
src/Rel8/Table/Insert.hsdeleted−39
@@ -1,39 +0,0 @@
1−{-# language FlexibleContexts #-}
2−{-# language NamedFieldPuns #-}
3−{-# language TypeFamilies #-}
4−{-# language ViewPatterns #-}
5−
6−module Rel8.Table.Insert
7− ( toInsert
8− , toInsertDefaults
9− )
10−where
11−
12−-- base
13−import Prelude
14−
15−-- rel8
16−import Rel8.Kind.Necessity ( SNecessity( SOptional, SRequired ) )
17−import Rel8.Schema.Context ( Col'(..) )
18−import Rel8.Schema.HTable ( hfield, htabulate, hspecs )
19−import Rel8.Schema.Spec ( SSpec(..) )
20−import Rel8.Table ( fromColumns, toColumns )
21−import Rel8.Table.Recontextualize ( Inserts )
22−
23−
24−toInsert :: Inserts exprs inserts => exprs -> inserts
25−toInsert (toColumns -> exprs) = fromColumns $ htabulate $ \field ->
26− case hfield hspecs field of
27− SSpec {necessity} -> case hfield exprs field of
28− DB expr -> case necessity of
29− SRequired -> RequiredInsert expr
30− SOptional -> OptionalInsert (Just expr)
31−
32−
33−toInsertDefaults :: Inserts exprs inserts => exprs -> inserts
34−toInsertDefaults (toColumns -> exprs) = fromColumns $ htabulate $ \field ->
35− case hfield hspecs field of
36− SSpec {necessity} -> case hfield exprs field of
37− DB expr -> case necessity of
38− SRequired -> RequiredInsert expr
39− SOptional -> OptionalInsert Nothing
src/Rel8/Table/Lifted.hsdeleted−57
@@ -1,57 +0,0 @@
1−{-# language ConstrainedClassMethods #-}
2−{-# language DataKinds #-}
3−{-# language FlexibleContexts #-}
4−{-# language FlexibleInstances #-}
5−{-# language StandaloneKindSignatures #-}
6−{-# language TypeFamilies #-}
7−
8−module Rel8.Table.Lifted
9− ( Table1( Columns1, ConstrainContext1, toColumns1, fromColumns1 )
10− , Table2( Columns2, ConstrainContext2, toColumns2, fromColumns2 )
11− )
12−where
13−
14−-- base
15−import Data.Kind ( Constraint, Type )
16−import Prelude ()
17−
18−-- rel8
19−import Rel8.Schema.Context ( Interpretation, Col )
20−import Rel8.Schema.HTable ( HTable )
21−import qualified Rel8.Schema.Kind as K
22−
23−
24−type Table1 :: (Type -> Type) -> Constraint
25−class Table1 f where
26− type Columns1 f :: K.HTable -> K.HTable
27− type ConstrainContext1 f :: K.Context -> Constraint
28− type ConstrainContext1 _ = Interpretation
29−
30− toColumns1 :: (ConstrainContext1 f context, HTable t)
31− => (a -> t (Col context))
32− -> f a
33− -> Columns1 f t (Col context)
34−
35− fromColumns1 :: (ConstrainContext1 f context, HTable t)
36− => (t (Col context) -> a)
37− -> Columns1 f t (Col context)
38− -> f a
39−
40−
41−type Table2 :: (Type -> Type -> Type) -> Constraint
42−class Table2 p where
43− type Columns2 p :: K.HTable -> K.HTable -> K.HTable
44− type ConstrainContext2 p :: K.Context -> Constraint
45− type ConstrainContext2 _ = Interpretation
46−
47− toColumns2 :: (ConstrainContext2 p context, HTable t, HTable u)
48− => (a -> t (Col context))
49− -> (b -> u (Col context))
50− -> p a b
51− -> Columns2 p t u (Col context)
52−
53− fromColumns2 :: (ConstrainContext2 p context, HTable t, HTable u)
54− => (t (Col context) -> a)
55− -> (u (Col context) -> b)
56− -> Columns2 p t u (Col context)
57− -> p a b
src/Rel8/Table/List.hs+106−21
@@ -1,64 +1,149 @@
1+{-# language DataKinds #-}
1{-# language FlexibleContexts #-}
2{-# language FlexibleContexts #-}
2{-# language FlexibleInstances #-}
3{-# language FlexibleInstances #-}
3{-# language MultiParamTypeClasses #-}
4{-# language MultiParamTypeClasses #-}
5+{-# language NamedFieldPuns #-}
6+{-# language ScopedTypeVariables #-}
4{-# language StandaloneKindSignatures #-}
7{-# language StandaloneKindSignatures #-}
8+{-# language TypeApplications #-}
5{-# language TypeFamilies #-}
9{-# language TypeFamilies #-}
6{-# language UndecidableInstances #-}
10{-# language UndecidableInstances #-}
7
11
8module Rel8.Table.List
12module Rel8.Table.List
9 ( ListTable(..)
13 ( ListTable(..)
14+ , ($*)
15+ , listTable
16+ , nameListTable
10 )
17 )
11where
18where
12
19
13-- base
20-- base
21+import Data.Functor.Identity ( Identity( Identity ) )
14import Data.Kind ( Type )
22import Data.Kind ( Type )
15import Prelude
23import Prelude
16
24
17-- rel8
25-- rel8
18import Rel8.Expr ( Expr )
26import Rel8.Expr ( Expr )
19−import Rel8.Expr.Array ( sappend, sempty )
27+import Rel8.Expr.Array ( sappend, sempty, slistOf )
20−import Rel8.Schema.Context ( Col, Col'(..) )
28+import Rel8.Schema.Dict ( Dict( Dict ) )
21import Rel8.Schema.HTable.List ( HListTable )
29import Rel8.Schema.HTable.List ( HListTable )
22−import Rel8.Schema.HTable.Vectorize ( happend, hempty )
30+import Rel8.Schema.HTable.Vectorize
31+ ( hvectorize, hunvectorize
32+ , happend, hempty
33+ , hproject, hcolumn
34+ )
35+import qualified Rel8.Schema.Kind as K
36+import Rel8.Schema.Name ( Name( Name ) )
37+import Rel8.Schema.Null ( Nullity( Null, NotNull ) )
38+import Rel8.Schema.Result ( vectorizer, unvectorizer )
39+import Rel8.Schema.Spec ( Spec(..) )
40+import Rel8.Table
23−import Rel8.Table ( Table, Context, Columns, fromColumns, toColumns )
41+ ( Table, Context, Columns, fromColumns, toColumns
42+ , FromExprs, fromResult, toResult
43+ , Transpose
44+ )
24import Rel8.Table.Alternative
45import Rel8.Table.Alternative
25 ( AltTable, (<|>:)
46 ( AltTable, (<|>:)
26 , AlternativeTable, emptyTable
47 , AlternativeTable, emptyTable
27 )
48 )
28−import Rel8.Table.Recontextualize ( Recontextualize )
49+import Rel8.Table.Eq ( EqTable, eqTable )
50+import Rel8.Table.Ord ( OrdTable, ordTable )
51+import Rel8.Table.Projection
52+ ( Projectable, Projecting, Projection, project, apply
53+ )
54+import Rel8.Table.Serialize ( ToExprs )
29
55
30
56
31-- | A @ListTable@ value contains zero or more instances of @a@. You construct
57-- | A @ListTable@ value contains zero or more instances of @a@. You construct
32−-- @ListTable@s with 'many' or 'listAgg'.
58+-- @ListTable@s with 'Rel8.many' or 'Rel8.listAgg'.
33−type ListTable :: Type -> Type
59+type ListTable :: K.Context -> Type -> Type
60+newtype ListTable context a =
34−newtype ListTable a = ListTable (HListTable (Columns a) (Col (Context a)))
61+ ListTable (HListTable (Columns a) (Context a))
62+
35
63
64+instance Projectable (ListTable context) where
65+ project f (ListTable a) = ListTable (hproject (apply f) a)
36
66
67+
68+instance (Table context a, context ~ context') =>
37−instance Table context a => Table context (ListTable a) where
69+ Table context' (ListTable context a)
70+ where
38− type Columns (ListTable a) = HListTable (Columns a)
71+ type Columns (ListTable context a) = HListTable (Columns a)
39− type Context (ListTable a) = Context a
72+ type Context (ListTable context a) = Context a
73+ type FromExprs (ListTable context a) = [FromExprs a]
74+ type Transpose to (ListTable context a) = ListTable to (Transpose to a)
40
75
41 fromColumns = ListTable
76 fromColumns = ListTable
42 toColumns (ListTable a) = a
77 toColumns (ListTable a) = a
78+ fromResult = fmap (fromResult @_ @a) . hunvectorize unvectorizer
79+ toResult = hvectorize vectorizer . fmap (toResult @_ @a)
80+
81+
82+instance (EqTable a, context ~ Expr) => EqTable (ListTable context a) where
83+ eqTable =
84+ hvectorize
85+ (\Spec {nullity} (Identity Dict) -> case nullity of
86+ Null -> Dict
87+ NotNull -> Dict)
88+ (Identity (eqTable @a))
89+
43
90
91+instance (OrdTable a, context ~ Expr) => OrdTable (ListTable context a) where
92+ ordTable =
93+ hvectorize
94+ (\Spec {nullity} (Identity Dict) -> case nullity of
95+ Null -> Dict
96+ NotNull -> Dict)
97+ (Identity (ordTable @a))
44
98
45−instance Recontextualize from to a b =>
46− Recontextualize from to (ListTable a) (ListTable b)
47
99
100+instance (ToExprs exprs a, context ~ Expr) =>
101+ ToExprs (ListTable context exprs) [a]
48
102
103+
49−instance AltTable ListTable where
104+instance context ~ Expr => AltTable (ListTable context) where
50 (<|>:) = (<>)
105 (<|>:) = (<>)
51
106
52
107
53−instance AlternativeTable ListTable where
108+instance context ~ Expr => AlternativeTable (ListTable context) where
54 emptyTable = mempty
109 emptyTable = mempty
55
110
56
111
57−instance Table Expr a => Semigroup (ListTable a) where
112+instance (context ~ Expr, Table Expr a) => Semigroup (ListTable context a)
113+ where
58− ListTable as <> ListTable bs = ListTable $
114+ ListTable as <> ListTable bs = ListTable $ happend (const sappend) as bs
59− happend (\_ _ (DB a) (DB b) -> DB (sappend a b)) as bs
115+
116+
117+instance (context ~ Expr, Table Expr a) =>
118+ Monoid (ListTable context a)
119+ where
120+ mempty = ListTable $ hempty $ \Spec {info} -> sempty info
121+
122+
123+-- | Project a single expression out of a 'ListTable'.
124+($*) :: Projecting a (Expr b)
125+ => Projection a (Expr b) -> ListTable Expr a -> Expr [b]
126+f $* ListTable a = hcolumn $ hproject (apply f) a
127+infixl 4 $*
128+
129+
130+-- | Construct a @ListTable@ from a list of expressions.
131+listTable :: Table Expr a => [a] -> ListTable Expr a
132+listTable =
133+ ListTable .
134+ hvectorize (\Spec {info} -> slistOf info) .
135+ fmap toColumns
60
136
61
137
62−instance Table Expr a => Monoid (ListTable a) where
138+-- | Construct a 'ListTable' in the 'Name' context. This can be useful if you
139+-- have a 'ListTable' that you are storing in a table and need to construct a
140+-- 'TableSchema'.
141+nameListTable
142+ :: Table Name a
143+ => a -- ^ The names of the columns of elements of the list.
144+ -> ListTable Name a
145+nameListTable =
63− mempty = ListTable $ hempty $ \nullability info ->
146+ ListTable .
64− DB (sempty nullability info)
147+ hvectorize (\_ (Identity (Name a)) -> Name a) .
148+ pure .
149+ toColumns
src/Rel8/Table/Maybe.hs+132−90
@@ -15,45 +15,53 @@ module Rel8.Table.Maybe
15 ( MaybeTable(..)
15 ( MaybeTable(..)
16 , maybeTable, nothingTable, justTable
16 , maybeTable, nothingTable, justTable
17 , isNothingTable, isJustTable
17 , isNothingTable, isJustTable
18+ , fromMaybeTable
18 , ($?)
19 , ($?)
20+ , aggregateMaybeTable
21+ , nameMaybeTable
19 )
22 )
20where
23where
21
24
22-- base
25-- base
23−import Data.Functor.Identity ( runIdentity )
26+import Data.Functor ( ($>) )
27+import Data.Functor.Identity ( Identity( Identity ) )
24import Data.Kind ( Type )
28import Data.Kind ( Type )
29+import Data.Maybe ( fromMaybe, isJust )
25−import Prelude hiding ( null, repeat, undefined, zipWith )
30+import Prelude hiding ( null, undefined )
31+
32+-- comonad
33+import Control.Comonad ( extract )
26
34
27-- rel8
35-- rel8
36+import Rel8.Aggregate ( Aggregate )
28import Rel8.Expr ( Expr )
37import Rel8.Expr ( Expr )
38+import Rel8.Expr.Aggregate ( groupByExpr )
29import Rel8.Expr.Bool ( boolExpr )
39import Rel8.Expr.Bool ( boolExpr )
30import Rel8.Expr.Null ( isNull, isNonNull, null, nullify )
40import Rel8.Expr.Null ( isNull, isNonNull, null, nullify )
31−import Rel8.Expr.Serialize ( litExpr )
41+import Rel8.Kind.Context ( Reifiable )
32−import Rel8.Schema.Context.Label ( Labelable, labeler, unlabeler )
42+import Rel8.Schema.Dict ( Dict( Dict ) )
33−import Rel8.Schema.Context.Nullify
43+import qualified Rel8.Schema.Kind as K
34− ( Nullifiable
35− , encodeTag, decodeTag
36− , nullifier, unnullifier
37− )
38import Rel8.Schema.HTable.Identity ( HIdentity(..) )
44import Rel8.Schema.HTable.Identity ( HIdentity(..) )
39−import Rel8.Schema.HTable.Label ( HLabel, hlabel, hunlabel )
45+import Rel8.Schema.HTable.Label ( hlabel, hunlabel )
40import Rel8.Schema.HTable.Maybe ( HMaybeTable(..) )
46import Rel8.Schema.HTable.Maybe ( HMaybeTable(..) )
41−import Rel8.Schema.HTable.Nullify ( hnullify, hunnullify )
47+import Rel8.Schema.Name ( Name )
42−import Rel8.Schema.Nullability
48+import Rel8.Schema.Null ( Nullity( Null, NotNull ), Sql, nullable )
43− ( Nullify
49+import qualified Rel8.Schema.Null as N
44− , Nullability( Nullable, NonNullable )
50+import Rel8.Table
45− , Sql, nullabilization
51+ ( Table, Columns, Context, fromColumns, toColumns
52+ , FromExprs, fromResult, toResult
53+ , Transpose
46 )
54 )
47−import Rel8.Table ( Table, Columns, Context, fromColumns, toColumns )
48import Rel8.Table.Alternative
55import Rel8.Table.Alternative
49 ( AltTable, (<|>:)
56 ( AltTable, (<|>:)
50 , AlternativeTable, emptyTable
57 , AlternativeTable, emptyTable
51 )
58 )
52import Rel8.Table.Bool ( bool )
59import Rel8.Table.Bool ( bool )
53−import Rel8.Table.Lifted
60+import Rel8.Table.Eq ( EqTable, eqTable )
54− ( Table1, Columns1, ConstrainContext1, fromColumns1, toColumns1
61+import Rel8.Table.Ord ( OrdTable, ordTable )
55− )
62+import Rel8.Table.Projection ( Projectable, project )
56−import Rel8.Table.Recontextualize ( Recontextualize )
63+import Rel8.Table.Nullify ( Nullify, aggregateNullify, guard )
64+import Rel8.Table.Serialize ( ToExprs )
57import Rel8.Table.Undefined ( undefined )
65import Rel8.Table.Undefined ( undefined )
58import Rel8.Type ( DBType )
66import Rel8.Type ( DBType )
59import Rel8.Type.Tag ( MaybeTag( IsJust ) )
67import Rel8.Type.Tag ( MaybeTag( IsJust ) )
@@ -71,134 +79,168 @@ import Data.Functor.Bind ( Bind, (>>-) )
71-- entirely of nulls, you can't distinguish if you matched an all null row, or
79-- entirely of nulls, you can't distinguish if you matched an all null row, or
72-- if the match failed. For this reason @MaybeTable@ contains an extra field -
80-- if the match failed. For this reason @MaybeTable@ contains an extra field -
73-- a "nullTag" - to track whether or not the outer join produced any rows.
81-- a "nullTag" - to track whether or not the outer join produced any rows.
74−type MaybeTable :: Type -> Type
82+type MaybeTable :: K.Context -> Type -> Type
75−data MaybeTable a = MaybeTable
83+data MaybeTable context a = MaybeTable
76− { tag :: Expr (Maybe MaybeTag)
84+ { tag :: context (Maybe MaybeTag)
77− , just :: a
85+ , just :: Nullify context a
78 }
86 }
79− deriving stock (Show, Functor)
87+ deriving stock Functor
88+
89+
90+instance Projectable (MaybeTable context) where
91+ project f (MaybeTable tag a) = MaybeTable tag (project f a)
80
92
81
93
82−instance Apply MaybeTable where
94+instance context ~ Expr => Apply (MaybeTable context) where
83− MaybeTable tag f <.> MaybeTable tag' a = MaybeTable (tag <> tag') (f a)
95+ MaybeTable tag f <.> MaybeTable tag' a = MaybeTable (tag <> tag') (f <.> a)
84
96
85
97
86-- | Has the same behavior as the @Applicative@ instance for @Maybe@. See also:
98-- | Has the same behavior as the @Applicative@ instance for @Maybe@. See also:
87−-- 'traverseMaybeTable'.
99+-- 'Rel8.traverseMaybeTable'.
88−instance Applicative MaybeTable where
100+instance context ~ Expr => Applicative (MaybeTable context) where
89 (<*>) = (<.>)
101 (<*>) = (<.>)
90 pure = justTable
102 pure = justTable
91
103
92
104
93−instance Bind MaybeTable where
105+instance context ~ Expr => Bind (MaybeTable context) where
94− MaybeTable tag a >>- f = case f a of
106+ MaybeTable tag a >>- f = case f (extract a) of
95 MaybeTable tag' b -> MaybeTable (tag <> tag') b
107 MaybeTable tag' b -> MaybeTable (tag <> tag') b
96
108
97
109
98−-- | Has the same behavior as the @Monad@ instance for @Maybe@. See also:
110+-- | Has the same behavior as the @Monad@ instance for @Maybe@.
99−-- 'bindMaybeTable'.
100−instance Monad MaybeTable where
111+instance context ~ Expr => Monad (MaybeTable context) where
101 (>>=) = (>>-)
112 (>>=) = (>>-)
102
113
103
114
104−instance AltTable MaybeTable where
115+instance context ~ Expr => AltTable (MaybeTable context) where
105− ma@(MaybeTable tag a) <|>: MaybeTable tag' b = MaybeTable
106− { tag = boolExpr tag tag' condition
107− , just = bool a b condition
108− }
109− where
110− condition = isNothingTable ma
116+ ma <|>: mb = bool ma mb (isNothingTable ma)
111
117
112
118
113−instance AlternativeTable MaybeTable where
119+instance context ~ Expr => AlternativeTable (MaybeTable context) where
114 emptyTable = nothingTable
120 emptyTable = nothingTable
115
121
116
122
117−instance (Table Expr a, Semigroup a) => Semigroup (MaybeTable a) where
123+instance (context ~ Expr, Table Expr a, Semigroup a) =>
124+ Semigroup (MaybeTable context a)
125+ where
118 ma <> mb = maybeTable mb (\a -> maybeTable ma (justTable . (a <>)) mb) ma
126 ma <> mb = maybeTable mb (\a -> maybeTable ma (justTable . (a <>)) mb) ma
119
127
120
128
121−instance (Table Expr a, Semigroup a) => Monoid (MaybeTable a) where
129+instance (context ~ Expr, Table Expr a, Semigroup a) =>
130+ Monoid (MaybeTable context a)
131+ where
122 mempty = nothingTable
132 mempty = nothingTable
123
133
124
134
125−instance Table1 MaybeTable where
135+instance (Table context a, Reifiable context, context ~ context') =>
136+ Table context' (MaybeTable context a)
137+ where
126− type Columns1 MaybeTable = HMaybeTable
138+ type Columns (MaybeTable context a) = HMaybeTable (Columns a)
127− type ConstrainContext1 MaybeTable = Nullifiable
139+ type Context (MaybeTable context a) = Context a
140+ type FromExprs (MaybeTable context a) = Maybe (FromExprs a)
141+ type Transpose to (MaybeTable context a) = MaybeTable to (Transpose to a)
142+
143+ toColumns MaybeTable {tag, just} = HMaybeTable
144+ { htag = hlabel $ HIdentity tag
145+ , hjust = hlabel $ guard tag isJust isNonNull $ toColumns just
146+ }
128
147
129− toColumns1 f MaybeTable {tag, just} = HMaybeTable
148+ fromColumns HMaybeTable {htag, hjust} = MaybeTable
130− { htag
149+ { tag = unHIdentity $ hunlabel htag
131− , hjust = hnullify (nullifier (isNonNull tag)) $ f just
150+ , just = fromColumns $ hunlabel hjust
132 }
151 }
133− where
134− htag = HIdentity (encodeTag tag)
135
152
136− fromColumns1 f HMaybeTable {htag = HIdentity htag, hjust} = MaybeTable
153+ toResult ma = HMaybeTable
137− { tag
154+ { htag = hlabel (HIdentity (Identity (IsJust <$ ma)))
138− , just = f $ runIdentity $
155+ , hjust = hlabel (toResult @_ @(Nullify context a) ma)
139− hunnullify (\a -> pure . unnullifier (isNonNull tag) a) hjust
140 }
156 }
157+
158+ fromResult HMaybeTable {htag, hjust} = case hunlabel htag of
159+ HIdentity (Identity tag) -> tag $>
160+ fromMaybe err (fromResult @_ @(Nullify context a) (hunlabel hjust))
141 where
161 where
142− tag = decodeTag htag
162+ err = error "Maybe.fromColumns: mismatch between tag and data"
143
163
144− {-# INLINABLE fromColumns1 #-}
145− {-# INLINABLE toColumns1 #-}
146
164
165+instance (EqTable a, context ~ Expr) => EqTable (MaybeTable context a) where
166+ eqTable = HMaybeTable
167+ { htag = hlabel (HIdentity Dict)
168+ , hjust = hlabel (eqTable @(Nullify context a))
169+ }
147
170
148−instance
149− ( Table context a
150− , Labelable context, Nullifiable context
151− ) => Table context (MaybeTable a)
152− where
153− type Columns (MaybeTable a) = HMaybeTable (HLabel "Just" (Columns a))
154− type Context (MaybeTable a) = Context a
155
171
156− toColumns = toColumns1 (hlabel labeler . toColumns)
172+instance (OrdTable a, context ~ Expr) => OrdTable (MaybeTable context a) where
157− fromColumns = fromColumns1 (fromColumns . hunlabel unlabeler)
173+ ordTable = HMaybeTable
174+ { htag = hlabel (HIdentity Dict)
175+ , hjust = hlabel (ordTable @(Nullify context a))
176+ }
158
177
159
178
160−instance
179+instance (ToExprs exprs a, context ~ Expr) =>
161− ( Labelable from, Nullifiable from
180+ ToExprs (MaybeTable context exprs) (Maybe a)
162− , Labelable to, Nullifiable to
163− , Recontextualize from to a b
164− ) => Recontextualize from to (MaybeTable a) (MaybeTable b)
165
181
166
182
167−-- | Check if a @MaybeTable@ is absent of any row.. Like 'isNothing'.
183+-- | Check if a @MaybeTable@ is absent of any row. Like 'Data.Maybe.isNothing'.
168−isNothingTable :: MaybeTable a -> Expr Bool
184+isNothingTable :: MaybeTable Expr a -> Expr Bool
169isNothingTable (MaybeTable tag _) = isNull tag
185isNothingTable (MaybeTable tag _) = isNull tag
170
186
171
187
172−-- | Check if a @MaybeTable@ contains a row. Like 'isJust'.
188+-- | Check if a @MaybeTable@ contains a row. Like 'Data.Maybe.isJust'.
173−isJustTable :: MaybeTable a -> Expr Bool
189+isJustTable :: MaybeTable Expr a -> Expr Bool
174isJustTable (MaybeTable tag _) = isNonNull tag
190isJustTable (MaybeTable tag _) = isNonNull tag
175
191
176
192
177-- | Perform case analysis on a 'MaybeTable'. Like 'maybe'.
193-- | Perform case analysis on a 'MaybeTable'. Like 'maybe'.
178−maybeTable :: Table Expr b => b -> (a -> b) -> MaybeTable a -> b
194+maybeTable :: Table Expr b => b -> (a -> b) -> MaybeTable Expr a -> b
179−maybeTable b f ma@(MaybeTable _ a) = bool (f a) b (isNothingTable ma)
195+maybeTable b f ma@(MaybeTable _ a) = bool (f (extract a)) b (isNothingTable ma)
196+{-# INLINABLE maybeTable #-}
180
197
181
198
182-- | The null table. Like 'Nothing'.
199-- | The null table. Like 'Nothing'.
183−nothingTable :: Table Expr a => MaybeTable a
200+nothingTable :: Table Expr a => MaybeTable Expr a
184−nothingTable = MaybeTable null undefined
201+nothingTable = MaybeTable null (pure undefined)
185
202
186
203
187-- | Lift any table into 'MaybeTable'. Like 'Just'. Note you can also use
204-- | Lift any table into 'MaybeTable'. Like 'Just'. Note you can also use
188-- 'pure'.
205-- 'pure'.
189−justTable :: a -> MaybeTable a
206+justTable :: a -> MaybeTable Expr a
190−justTable = MaybeTable (nullify (litExpr IsJust))
207+justTable = MaybeTable mempty . pure
208+
209+
210+-- | 'Data.Maybe.fromMaybe' for 'MaybeTable's.
211+fromMaybeTable :: Table Expr a => a -> MaybeTable Expr a -> a
212+fromMaybeTable fallback = maybeTable fallback id
191
213
192
214
193-- | Project a single expression out of a 'MaybeTable'. You can think of this
215-- | Project a single expression out of a 'MaybeTable'. You can think of this
194-- operator like the '$' operator, but it also has the ability to return
216-- operator like the '$' operator, but it also has the ability to return
195-- @null@.
217-- @null@.
196−--
197−-- >>> select c $ fmap (fst $?) (optional (values [lit (True, False)]))
198−-- [Just True]
199($?) :: forall a b. Sql DBType b
218($?) :: forall a b. Sql DBType b
200− => (a -> Expr b) -> MaybeTable a -> Expr (Nullify b)
219+ => (a -> Expr b) -> MaybeTable Expr a -> Expr (N.Nullify b)
201−f $? ma@(MaybeTable _ a) = case nullabilization @b of
220+f $? ma@(MaybeTable _ a) = case nullable @b of
202− Nullable -> boolExpr (f a) null (isNothingTable ma)
221+ Null -> boolExpr (f (extract a)) null (isNothingTable ma)
203− NonNullable -> boolExpr (nullify (f a)) null (isNothingTable ma)
222+ NotNull -> boolExpr (nullify (f (extract a))) null (isNothingTable ma)
204infixl 4 $?
223infixl 4 $?
224+
225+
226+-- | Lift an aggregating function to operate on a 'MaybeTable'.
227+-- @nothingTable@s and @justTable@s are grouped separately.
228+aggregateMaybeTable :: ()
229+ => (exprs -> aggregates)
230+ -> MaybeTable Expr exprs
231+ -> MaybeTable Aggregate aggregates
232+aggregateMaybeTable f (MaybeTable tag a) =
233+ MaybeTable (groupByExpr tag) (aggregateNullify f a)
234+
235+
236+-- | Construct a 'MaybeTable' in the 'Name' context. This can be useful if you
237+-- have a 'MaybeTable' that you are storing in a table and need to construct a
238+-- 'TableSchema'.
239+nameMaybeTable
240+ :: Name (Maybe MaybeTag)
241+ -- ^ The name of the column to track whether a row is a 'justTable' or
242+ -- 'nothingTable'.
243+ -> a
244+ -- ^ Names of the columns in @a@.
245+ -> MaybeTable Name a
246+nameMaybeTable tag = MaybeTable tag . pure
src/Rel8/Table/Name.hs+37−22
@@ -1,14 +1,17 @@
1+{-# language DataKinds #-}
1{-# language FlexibleContexts #-}
2{-# language FlexibleContexts #-}
3+{-# language FlexibleInstances #-}
4+{-# language MultiParamTypeClasses #-}
2{-# language NamedFieldPuns #-}
5{-# language NamedFieldPuns #-}
3{-# language ScopedTypeVariables #-}
6{-# language ScopedTypeVariables #-}
4{-# language TypeApplications #-}
7{-# language TypeApplications #-}
5{-# language TypeFamilies #-}
8{-# language TypeFamilies #-}
9+{-# language UndecidableInstances #-}
6{-# language ViewPatterns #-}
10{-# language ViewPatterns #-}
7
11
8module Rel8.Table.Name
12module Rel8.Table.Name
9 ( namesFromLabels
13 ( namesFromLabels
10 , namesFromLabelsWith
14 , namesFromLabelsWith
11− , showExprs
12 , showLabels
15 , showLabels
13 , showNames
16 , showNames
14 )
17 )
@@ -17,48 +20,60 @@ where
17-- base
20-- base
18import Data.Foldable ( fold )
21import Data.Foldable ( fold )
19import Data.Functor.Const ( Const( Const ), getConst )
22import Data.Functor.Const ( Const( Const ), getConst )
20−import Data.List.NonEmpty ( NonEmpty, intersperse )
23+import Data.List.NonEmpty ( NonEmpty, intersperse, nonEmpty )
24+import Data.Maybe ( fromMaybe )
21import Prelude
25import Prelude
22
26
23−-- casing
24−import Text.Casing ( quietSnake )
25−
26-- rel8
27-- rel8
27−import Rel8.Expr ( Expr )
28−import Rel8.Kind.Labels ( renderLabels )
29−import Rel8.Schema.Context ( Col'(..), Name( Name ) )
30import Rel8.Schema.HTable ( htabulate, htabulateA, hfield, hspecs )
28import Rel8.Schema.HTable ( htabulate, htabulateA, hfield, hspecs )
31−import Rel8.Schema.Spec ( SSpec(..) )
29+import Rel8.Schema.Name ( Name( Name ) )
30+import Rel8.Schema.Spec ( Spec(..) )
32−import Rel8.Table ( Table, Columns, Context, fromColumns, toColumns )
31+import Rel8.Table ( Table(..) )
33
32
34
33
34+-- | Construct a table in the 'Name' context containing the names of all
35+-- columns. Nested column names will be combined with @/@.
36+--
37+-- See also: 'namesFromLabelsWith'.
35namesFromLabels :: Table Name a => a
38namesFromLabels :: Table Name a => a
36namesFromLabels = namesFromLabelsWith go
39namesFromLabels = namesFromLabelsWith go
37 where
40 where
38− go = fold . intersperse "/" . fmap quietSnake
41+ go = fold . intersperse "/"
39
42
40
43
44+-- | Construct a table in the 'Name' context containing the names of all
45+-- columns. The supplied function can be used to transform column names.
46+--
47+-- This function can be used to generically derive the columns for a
48+-- 'TableSchema'. For example,
49+--
50+-- @
51+-- myTableSchema :: TableSchema (MyTable Name)
52+-- myTableSchema = TableSchema
53+-- { columns = namesFromLabelsWith last
54+-- }
55+-- @
56+--
57+-- will construct a 'TableSchema' where each columns names exactly corresponds
58+-- to the name of the Haskell field.
41namesFromLabelsWith :: Table Name a
59namesFromLabelsWith :: Table Name a
42 => (NonEmpty String -> String) -> a
60 => (NonEmpty String -> String) -> a
43namesFromLabelsWith f = fromColumns $ htabulate $ \field ->
61namesFromLabelsWith f = fromColumns $ htabulate $ \field ->
44 case hfield hspecs field of
62 case hfield hspecs field of
45− SSpec {labels} -> Col (Name (f (renderLabels labels)))
63+ Spec {labels} -> Name (f (renderLabels labels))
46−
47−
48−showExprs :: Table Expr a => a -> [(String, String)]
49−showExprs as = case (namesFromLabels, toColumns as) of
50− (names, exprs) -> getConst $ htabulateA $ \field ->
51− case (hfield names field, hfield exprs field) of
52− (Col (Name name), DB expr) -> Const [(name, show expr)]
53
64
54
65
55showLabels :: forall a. Table (Context a) a => a -> [NonEmpty String]
66showLabels :: forall a. Table (Context a) a => a -> [NonEmpty String]
56showLabels _ = getConst $
67showLabels _ = getConst $
57 htabulateA @(Columns a) $ \field -> case hfield hspecs field of
68 htabulateA @(Columns a) $ \field -> case hfield hspecs field of
58− SSpec {labels} -> Const [renderLabels labels]
69+ Spec {labels} -> Const (pure (renderLabels labels))
59
70
60
71
61−showNames :: forall a. Table Name a => a -> [String]
72+showNames :: forall a. Table Name a => a -> NonEmpty String
62showNames (toColumns -> names) = getConst $
73showNames (toColumns -> names) = getConst $
63 htabulateA @(Columns a) $ \field -> case hfield names field of
74 htabulateA @(Columns a) $ \field -> case hfield names field of
64− Col (Name name) -> Const [name]
75+ Name name -> Const (pure name)
76+
77+
78+renderLabels :: [String] -> NonEmpty String
79+renderLabels labels = fromMaybe (pure "anon") (nonEmpty labels )
src/Rel8/Table/NonEmpty.hs+109−19
@@ -1,53 +1,143 @@
1+{-# language DataKinds #-}
2+{-# language FlexibleContexts #-}
1{-# language FlexibleInstances #-}
3{-# language FlexibleInstances #-}
2{-# language MultiParamTypeClasses #-}
4{-# language MultiParamTypeClasses #-}
5+{-# language NamedFieldPuns #-}
6+{-# language ScopedTypeVariables #-}
3{-# language StandaloneKindSignatures #-}
7{-# language StandaloneKindSignatures #-}
8+{-# language TypeApplications #-}
4{-# language TypeFamilies #-}
9{-# language TypeFamilies #-}
5{-# language UndecidableInstances #-}
10{-# language UndecidableInstances #-}
6
11
7module Rel8.Table.NonEmpty
12module Rel8.Table.NonEmpty
8 ( NonEmptyTable(..)
13 ( NonEmptyTable(..)
9− , HNonEmptyTable
14+ , ($+)
15+ , nonEmptyTable
16+ , nameNonEmptyTable
10 )
17 )
11where
18where
12
19
13-- base
20-- base
21+import Data.Functor.Identity ( Identity( Identity ) )
14import Data.Kind ( Type )
22import Data.Kind ( Type )
23+import Data.List.NonEmpty ( NonEmpty )
15−import Prelude
24+import Prelude hiding ( id )
16
25
17-- rel8
26-- rel8
18import Rel8.Expr ( Expr )
27import Rel8.Expr ( Expr )
19−import Rel8.Expr.Array ( sappend1 )
28+import Rel8.Expr.Array ( sappend1, snonEmptyOf )
20−import Rel8.Schema.Context ( Col, Col'(..) )
29+import Rel8.Schema.Dict ( Dict( Dict ) )
21import Rel8.Schema.HTable.NonEmpty ( HNonEmptyTable )
30import Rel8.Schema.HTable.NonEmpty ( HNonEmptyTable )
22−import Rel8.Schema.HTable.Vectorize ( happend )
31+import Rel8.Schema.HTable.Vectorize
32+ ( hvectorize, hunvectorize
33+ , happend
34+ , hproject, hcolumn
35+ )
36+import qualified Rel8.Schema.Kind as K
37+import Rel8.Schema.Name ( Name( Name ) )
38+import Rel8.Schema.Null ( Nullity( Null, NotNull ) )
39+import Rel8.Schema.Result ( vectorizer, unvectorizer )
40+import Rel8.Schema.Spec ( Spec(..) )
41+import Rel8.Table
23−import Rel8.Table ( Table, Context, Columns, fromColumns, toColumns )
42+ ( Table, Context, Columns, fromColumns, toColumns
43+ , FromExprs, fromResult, toResult
44+ , Transpose
45+ )
24import Rel8.Table.Alternative ( AltTable, (<|>:) )
46import Rel8.Table.Alternative ( AltTable, (<|>:) )
25−import Rel8.Table.Recontextualize ( Recontextualize )
47+import Rel8.Table.Eq ( EqTable, eqTable )
48+import Rel8.Table.Ord ( OrdTable, ordTable )
49+import Rel8.Table.Projection
50+ ( Projectable, Projecting, Projection, project, apply
51+ )
52+import Rel8.Table.Serialize ( ToExprs )
26
53
27
54
28-- | A @NonEmptyTable@ value contains one or more instances of @a@. You
55-- | A @NonEmptyTable@ value contains one or more instances of @a@. You
29−-- construct @NonEmptyTable@s with 'some' or 'nonEmptyAgg'.
56+-- construct @NonEmptyTable@s with 'Rel8.some' or 'nonEmptyAgg'.
30−type NonEmptyTable :: Type -> Type
57+type NonEmptyTable :: K.Context -> Type -> Type
31−newtype NonEmptyTable a =
58+newtype NonEmptyTable context a =
32− NonEmptyTable (HNonEmptyTable (Columns a) (Col (Context a)))
59+ NonEmptyTable (HNonEmptyTable (Columns a) (Context a))
60+
33
61
62+instance Projectable (NonEmptyTable context) where
63+ project f (NonEmptyTable a) = NonEmptyTable (hproject (apply f) a)
34
64
65+
66+instance (Table context a, context ~ context') =>
35−instance Table context a => Table context (NonEmptyTable a) where
67+ Table context' (NonEmptyTable context a)
68+ where
36− type Columns (NonEmptyTable a) = HNonEmptyTable (Columns a)
69+ type Columns (NonEmptyTable context a) = HNonEmptyTable (Columns a)
37− type Context (NonEmptyTable a) = Context a
70+ type Context (NonEmptyTable context a) = Context a
71+ type FromExprs (NonEmptyTable context a) = NonEmpty (FromExprs a)
72+ type Transpose to (NonEmptyTable context a) =
73+ NonEmptyTable to (Transpose to a)
38
74
39 fromColumns = NonEmptyTable
75 fromColumns = NonEmptyTable
40 toColumns (NonEmptyTable a) = a
76 toColumns (NonEmptyTable a) = a
77+ fromResult = fmap (fromResult @_ @a) . hunvectorize unvectorizer
78+ toResult = hvectorize vectorizer . fmap (toResult @_ @a)
79+
80+
81+instance (EqTable a, context ~ Expr) =>
82+ EqTable (NonEmptyTable context a)
83+ where
84+ eqTable =
85+ hvectorize
86+ (\Spec {nullity} (Identity Dict) -> case nullity of
87+ Null -> Dict
88+ NotNull -> Dict)
89+ (Identity (eqTable @a))
90+
41
91
92+instance (OrdTable a, context ~ Expr) =>
93+ OrdTable (NonEmptyTable context a)
94+ where
95+ ordTable =
96+ hvectorize
97+ (\Spec {nullity} (Identity Dict) -> case nullity of
98+ Null -> Dict
99+ NotNull -> Dict)
100+ (Identity (ordTable @a))
42
101
43−instance Recontextualize from to a b =>
44− Recontextualize from to (NonEmptyTable a) (NonEmptyTable b)
45
102
103+instance (ToExprs exprs a, context ~ Expr) =>
104+ ToExprs (NonEmptyTable context exprs) (NonEmpty a)
46
105
106+
47−instance AltTable NonEmptyTable where
107+instance context ~ Expr => AltTable (NonEmptyTable context) where
48 (<|>:) = (<>)
108 (<|>:) = (<>)
49
109
50
110
51−instance Table Expr a => Semigroup (NonEmptyTable a) where
111+instance (Table Expr a, context ~ Expr) => Semigroup (NonEmptyTable context a)
112+ where
52 NonEmptyTable as <> NonEmptyTable bs = NonEmptyTable $
113 NonEmptyTable as <> NonEmptyTable bs = NonEmptyTable $
53− happend (\_ _ (DB a) (DB b) -> DB (sappend1 a b)) as bs
114+ happend (const sappend1) as bs
115+
116+
117+-- | Project a single expression out of a 'NonEmptyTable'.
118+($+) :: Projecting a (Expr b)
119+ => Projection a (Expr b) -> NonEmptyTable Expr a -> Expr (NonEmpty b)
120+f $+ NonEmptyTable a = hcolumn $ hproject (apply f) a
121+infixl 4 $+
122+
123+
124+-- | Construct a @NonEmptyTable@ from a non-empty list of expressions.
125+nonEmptyTable :: Table Expr a => NonEmpty a -> NonEmptyTable Expr a
126+nonEmptyTable =
127+ NonEmptyTable .
128+ hvectorize (\Spec {info} -> snonEmptyOf info) .
129+ fmap toColumns
130+
131+
132+-- | Construct a 'NonEmptyTable' in the 'Name' context. This can be useful if
133+-- you have a 'NonEmptyTable' that you are storing in a table and need to
134+-- construct a 'TableSchema'.
135+nameNonEmptyTable
136+ :: Table Name a
137+ => a -- ^ The names of the columns of elements of the list.
138+ -> NonEmptyTable Name a
139+nameNonEmptyTable =
140+ NonEmptyTable .
141+ hvectorize (\_ (Identity (Name a)) -> Name a) .
142+ pure .
143+ toColumns
src/Rel8/Table/Null.hsnew file+147
@@ -0,0 +1,147 @@
1+{-# language DataKinds #-}
2+{-# language FlexibleContexts #-}
3+{-# language FlexibleInstances #-}
4+{-# language MultiParamTypeClasses #-}
5+{-# language ScopedTypeVariables #-}
6+{-# language StandaloneKindSignatures #-}
7+{-# language TypeApplications #-}
8+{-# language TypeFamilies #-}
9+{-# language UndecidableInstances #-}
10+
11+module Rel8.Table.Null
12+ ( NullTable(..)
13+ , nullableTable, nullTable, nullifyTable, unsafeUnnullifyTable
14+ , isNullTable, isNonNullTable
15+ , nameNullTable
16+ , toMaybeTable, toNullTable
17+ )
18+where
19+
20+-- base
21+import Data.Kind ( Type )
22+import Prelude hiding ( null, undefined )
23+
24+-- comonad
25+import Control.Comonad ( extract )
26+
27+-- rel8
28+import Rel8.Expr ( Expr )
29+import Rel8.Expr.Bool ( not_ )
30+import Rel8.Kind.Context ( Reifiable )
31+import qualified Rel8.Schema.Kind as K
32+import Rel8.Schema.Name ( Name )
33+import Rel8.Table
34+ ( Table, Columns, Context, fromColumns, toColumns
35+ , FromExprs, fromResult, toResult
36+ , Transpose
37+ )
38+import Rel8.Table.Alternative
39+ ( AltTable, (<|>:)
40+ , AlternativeTable, emptyTable
41+ )
42+import Rel8.Table.Bool ( bool )
43+import Rel8.Table.Eq ( EqTable, eqTable )
44+import Rel8.Table.Maybe ( MaybeTable, justTable, maybeTable, nothingTable )
45+import Rel8.Table.Nullify ( Nullify, isNull )
46+import Rel8.Table.Ord ( OrdTable, ordTable )
47+import Rel8.Table.Projection ( Projectable, project )
48+import Rel8.Table.Serialize ( ToExprs )
49+import Rel8.Table.Undefined ( undefined )
50+
51+
52+-- | @NullTable t@ is the table @t@, but where all the columns in @t@ have the
53+-- possibility of being 'Rel8.null'. This is very similar to
54+-- 'Rel8.MaybeTable', except that it does not use an extra tag field, so it
55+-- cannot distinguish between @Nothing@ and @Just Nothing@ if nested. In other
56+-- words, if all of the columns of the @t@ passed to @NullTable@ are already
57+-- nullable, then @NullTable@ has no effect.
58+type NullTable :: K.Context -> Type -> Type
59+newtype NullTable context a = NullTable (Nullify context a)
60+
61+
62+instance Projectable (NullTable context) where
63+ project f (NullTable a) = NullTable (project f a)
64+
65+
66+instance context ~ Expr => AltTable (NullTable context) where
67+ ma <|>: mb = bool ma mb (isNullTable ma)
68+
69+
70+instance context ~ Expr => AlternativeTable (NullTable context) where
71+ emptyTable = nullTable
72+
73+
74+instance (Table context a, Reifiable context, context ~ context') =>
75+ Table context' (NullTable context a)
76+ where
77+ type Columns (NullTable context a) = Columns (Nullify context a)
78+ type Context (NullTable context a) = Context (Nullify context a)
79+ type FromExprs (NullTable context a) = FromExprs (Nullify context a)
80+ type Transpose to (NullTable context a) = NullTable to (Transpose to a)
81+
82+ toColumns (NullTable a) = toColumns a
83+ fromColumns = NullTable . fromColumns
84+
85+ toResult = toResult @_ @(Nullify context a)
86+ fromResult = fromResult @_ @(Nullify context a)
87+
88+
89+instance (EqTable a, context ~ Expr) => EqTable (NullTable context a) where
90+ eqTable = eqTable @(Nullify context a)
91+
92+
93+instance (OrdTable a, context ~ Expr) => OrdTable (NullTable context a) where
94+ ordTable = ordTable @(Nullify context a)
95+
96+
97+instance (ToExprs exprs a, context ~ Expr) =>
98+ ToExprs (NullTable context exprs) (Maybe a)
99+
100+
101+-- | Check if any of the non-nullable fields of @a@ are 'Rel8.null' under the
102+-- 'NullTable'. Returns 'Rel8.false' if @a@ has no non-nullable fields.
103+isNullTable :: Table Expr a => NullTable Expr a -> Expr Bool
104+isNullTable (NullTable a) = isNull a
105+
106+
107+-- | The inverse of 'isNullTable'.
108+isNonNullTable :: Table Expr a => NullTable Expr a -> Expr Bool
109+isNonNullTable = not_ . isNullTable
110+
111+
112+-- | Like 'Rel8.nullable'.
113+nullableTable :: (Table Expr a, Table Expr b)
114+ => b -> (a -> b) -> NullTable Expr a -> b
115+nullableTable b f ma@(NullTable a) = bool (f (extract a)) b (isNullTable ma)
116+
117+
118+-- | The null table. Like 'Rel8.null'.
119+nullTable :: Table Expr a => NullTable Expr a
120+nullTable = NullTable (pure undefined)
121+
122+
123+-- | Lift any table into 'NullTable'. Like 'Rel8.nullify'.
124+nullifyTable :: a -> NullTable Expr a
125+nullifyTable = NullTable . pure
126+
127+
128+unsafeUnnullifyTable :: NullTable Expr a -> a
129+unsafeUnnullifyTable (NullTable a) = extract a
130+
131+
132+-- | Construct a 'NullTable' in the 'Name' context. This can be useful if you
133+-- have a 'NullTable' that you are storing in a table and need to construct a
134+-- 'TableSchema'.
135+nameNullTable :: a -> NullTable Name a
136+nameNullTable = NullTable . pure
137+
138+
139+-- | Convert a 'NullTable' to a 'MaybeTable'.
140+toMaybeTable :: Table Expr a => NullTable Expr a -> MaybeTable Expr a
141+toMaybeTable = nullableTable nothingTable justTable
142+
143+
144+-- | Convert a 'MaybeTable' to a 'NullTable'. Note that if the underlying @a@
145+-- has no non-nullable fields, this is a lossy conversion.
146+toNullTable :: Table Expr a => MaybeTable Expr a -> NullTable Expr a
147+toNullTable = maybeTable nullTable nullifyTable
src/Rel8/Table/Nullify.hsnew file+211
@@ -0,0 +1,211 @@
1+{-# language DataKinds #-}
2+{-# language FlexibleContexts #-}
3+{-# language FlexibleInstances #-}
4+{-# language LambdaCase #-}
5+{-# language MultiParamTypeClasses #-}
6+{-# language NamedFieldPuns #-}
7+{-# language ScopedTypeVariables #-}
8+{-# language StandaloneKindSignatures #-}
9+{-# language TypeApplications #-}
10+{-# language TypeFamilies #-}
11+{-# language UndecidableInstances #-}
12+
13+module Rel8.Table.Nullify
14+ ( Nullify
15+ , aggregateNullify
16+ , guard
17+ , isNull
18+ )
19+where
20+
21+-- base
22+import Control.Applicative ( liftA2 )
23+import Data.Functor.Const ( Const( Const ), getConst )
24+import Data.Functor.Identity ( runIdentity )
25+import Data.Kind ( Type )
26+import Prelude
27+
28+-- comonad
29+import Control.Comonad ( Comonad, duplicate, extract, ComonadApply, (<@>) )
30+
31+-- rel8
32+import Rel8.Aggregate ( Aggregate )
33+import Rel8.Expr ( Expr )
34+import Rel8.Expr.Bool ( (||.), false )
35+import qualified Rel8.Expr.Null as Expr
36+import Rel8.Kind.Context ( Reifiable, contextSing )
37+import Rel8.Schema.Context.Nullify
38+ ( Nullifiability( NAggregate, NExpr )
39+ , NonNullifiability
40+ , Nullifiable, nullifiability
41+ , nullifiableOrNot, absurd
42+ , guarder
43+ , nullifier
44+ , unnullifier
45+ )
46+import Rel8.Schema.Dict ( Dict( Dict ) )
47+import Rel8.Schema.HTable ( HTable )
48+import Rel8.Schema.HTable.Nullify
49+ ( HNullify, hnulls, hnullify, hunnullify
50+ , hguard
51+ , hproject
52+ )
53+import qualified Rel8.Schema.Kind as K
54+import Rel8.Schema.Null ( Nullity( NotNull, Null ) )
55+import qualified Rel8.Schema.Result as R
56+import Rel8.Table
57+ ( Table, Columns, Context, toColumns, fromColumns
58+ , FromExprs, fromResult, toResult
59+ , Transpose
60+ )
61+import Rel8.Schema.Spec ( Spec( Spec, nullity ) )
62+import Rel8.Table.Eq ( EqTable, eqTable )
63+import Rel8.Table.Ord ( OrdTable, ordTable )
64+import Rel8.Table.Projection ( Projectable, apply, project )
65+
66+-- semigroupoids
67+import Data.Functor.Apply ( Apply, (<.>), liftF2 )
68+import Data.Functor.Bind ( Bind, (>>-) )
69+import Data.Functor.Extend ( Extend, duplicated )
70+
71+
72+type Nullify :: K.Context -> Type -> Type
73+data Nullify context a
74+ = Table (Nullifiability context) a
75+ | Fields (NonNullifiability context) (HNullify (Columns a) (Context a))
76+
77+
78+instance Projectable (Nullify context) where
79+ project f = \case
80+ Table nullifiable a -> Table nullifiable (fromColumns (apply f (toColumns a)))
81+ Fields nonNullifiable a -> Fields nonNullifiable (hproject (apply f) a)
82+
83+
84+instance Nullifiable context => Functor (Nullify context) where
85+ fmap f = \case
86+ Table nullifiable a -> Table nullifiable (f a)
87+ Fields notNullifiable _ -> absurd nullifiability notNullifiable
88+
89+
90+instance Nullifiable context => Foldable (Nullify context) where
91+ foldMap f = \case
92+ Table _ a -> f a
93+ Fields notNullifiable _ -> absurd nullifiability notNullifiable
94+
95+
96+instance Nullifiable context => Traversable (Nullify context) where
97+ traverse f = \case
98+ Table nullifiable a -> Table nullifiable <$> f a
99+ Fields notNullifiable _ -> absurd nullifiability notNullifiable
100+
101+
102+instance Nullifiable context => Apply (Nullify context) where
103+ liftF2 f = \case
104+ Table nullifiable a -> \case
105+ Table _ b -> Table nullifiable (f a b)
106+ Fields notNullifiable _ -> absurd nullifiable notNullifiable
107+ Fields notNullifiable _ -> absurd nullifiability notNullifiable
108+
109+
110+instance Nullifiable context => Applicative (Nullify context) where
111+ pure = Table nullifiability
112+ liftA2 = liftF2
113+
114+
115+instance Nullifiable context => Bind (Nullify context) where
116+ Table _ a >>- f = f a
117+ Fields notNullifiable _ >>- _ = absurd nullifiability notNullifiable
118+
119+
120+instance Nullifiable context => Monad (Nullify context) where
121+ (>>=) = (>>-)
122+
123+
124+instance Nullifiable context => Extend (Nullify context) where
125+ duplicated = \case
126+ Table nullifiable a -> Table nullifiable (Table nullifiable a)
127+ Fields notNullifiable _ -> absurd nullifiability notNullifiable
128+
129+
130+instance Nullifiable context => Comonad (Nullify context) where
131+ extract = \case
132+ Table _ a -> a
133+ Fields notNullifiable _ -> absurd nullifiability notNullifiable
134+ duplicate = duplicated
135+
136+
137+instance Nullifiable context => ComonadApply (Nullify context) where
138+ (<@>) = (<.>)
139+
140+
141+instance (Table context a, Reifiable context, context ~ context') =>
142+ Table context' (Nullify context a)
143+ where
144+ type Columns (Nullify context a) = HNullify (Columns a)
145+ type Context (Nullify context a) = Context a
146+ type FromExprs (Nullify context a) = Maybe (FromExprs a)
147+ type Transpose to (Nullify context a) = Nullify to (Transpose to a)
148+
149+ fromColumns = case nullifiableOrNot contextSing of
150+ Left notNullifiable -> Fields notNullifiable
151+ Right nullifiable ->
152+ Table nullifiable .
153+ fromColumns .
154+ runIdentity .
155+ hunnullify (\spec -> pure . unnullifier nullifiable spec)
156+
157+ toColumns = \case
158+ Table nullifiable a -> hnullify (nullifier nullifiable) (toColumns a)
159+ Fields _ a -> a
160+
161+ fromResult = fmap (fromResult @_ @a) . hunnullify R.unnullifier
162+
163+ toResult =
164+ maybe (hnulls (const R.null)) (hnullify R.nullifier) .
165+ fmap (toResult @_ @a)
166+
167+
168+instance (EqTable a, context ~ Expr) => EqTable (Nullify context a) where
169+ eqTable = hnullify (\_ Dict -> Dict) (eqTable @a)
170+
171+
172+instance (OrdTable a, context ~ Expr) => OrdTable (Nullify context a) where
173+ ordTable = hnullify (\_ Dict -> Dict) (ordTable @a)
174+
175+
176+aggregateNullify :: ()
177+ => (exprs -> aggregates)
178+ -> Nullify Expr exprs
179+ -> Nullify Aggregate aggregates
180+aggregateNullify f = \case
181+ Table _ a -> Table NAggregate (f a)
182+ Fields notNullifiable _ -> absurd NExpr notNullifiable
183+
184+
185+guard :: (Reifiable context, HTable t)
186+ => context tag
187+ -> (tag -> Bool)
188+ -> (Expr tag -> Expr Bool)
189+ -> HNullify t context
190+ -> HNullify t context
191+guard tag isNonNull isNonNullExpr =
192+ hguard (guarder contextSing tag isNonNull isNonNullExpr)
193+
194+
195+isNull :: forall a. Table Expr a => Nullify Expr a -> Expr Bool
196+isNull =
197+ maybe false getAny .
198+ getConst .
199+ hunnullify (\Spec {nullity} a -> Const $ case nullity of
200+ NotNull -> Just $ Any $ Expr.isNull a
201+ Null -> Nothing) .
202+ toColumns
203+
204+
205+newtype Any = Any
206+ { getAny :: Expr Bool
207+ }
208+
209+
210+instance Semigroup Any where
211+ Any a <> Any b = Any (a ||. b)
src/Rel8/Table/Opaleye.hs+93−73
@@ -1,130 +1,150 @@
1+{-# language BlockArguments #-}
2+{-# language DataKinds #-}
1{-# language DisambiguateRecordFields #-}
3{-# language DisambiguateRecordFields #-}
2{-# language FlexibleContexts #-}
4{-# language FlexibleContexts #-}
3{-# language NamedFieldPuns #-}
5{-# language NamedFieldPuns #-}
6+{-# language RankNTypes #-}
4{-# language TypeFamilies #-}
7{-# language TypeFamilies #-}
5{-# language ViewPatterns #-}
8{-# language ViewPatterns #-}
6
9
10+{-# options_ghc -Wno-deprecations #-}
11+
7module Rel8.Table.Opaleye
12module Rel8.Table.Opaleye
8 ( aggregator
13 ( aggregator
14+ , attributes
9 , binaryspec
15 , binaryspec
10 , distinctspec
16 , distinctspec
17+ , exprs
18+ , exprsWithNames
11 , table
19 , table
12 , tableFields
20 , tableFields
13 , unpackspec
21 , unpackspec
14 , valuesspec
22 , valuesspec
23+ , view
24+ , castTable
15 )
25 )
16where
26where
17
27
18-- base
28-- base
19−import Prelude hiding ( undefined )
29+import Data.Functor.Const ( Const( Const ), getConst )
30+import Data.List.NonEmpty ( NonEmpty )
31+import Prelude
20
32
21-- opaleye
33-- opaleye
34+import qualified Opaleye.Adaptors as Opaleye
35+import qualified Opaleye.Field as Opaleye ( Field_ )
22import qualified Opaleye.Internal.Aggregate as Opaleye
36import qualified Opaleye.Internal.Aggregate as Opaleye
23−import qualified Opaleye.Internal.Binary as Opaleye
24−import qualified Opaleye.Internal.Distinct as Opaleye
25import qualified Opaleye.Internal.HaskellDB.PrimQuery as Opaleye
37import qualified Opaleye.Internal.HaskellDB.PrimQuery as Opaleye
26−import qualified Opaleye.Internal.PackMap as Opaleye
27−import qualified Opaleye.Internal.Unpackspec as Opaleye
28import qualified Opaleye.Internal.Values as Opaleye
38import qualified Opaleye.Internal.Values as Opaleye
29−import qualified Opaleye.Internal.Table as Opaleye
39+import qualified Opaleye.Table as Opaleye
30
40
31-- profunctors
41-- profunctors
32import Data.Profunctor ( dimap, lmap )
42import Data.Profunctor ( dimap, lmap )
33
43
34-- rel8
44-- rel8
35−import Rel8.Aggregate ( Aggregate( Aggregate ) )
45+import Rel8.Aggregate ( Aggregate( Aggregate ), Aggregates )
36import Rel8.Expr ( Expr )
46import Rel8.Expr ( Expr )
37import Rel8.Expr.Opaleye
47import Rel8.Expr.Opaleye
38− ( scastExpr
39− , fromPrimExpr, toPrimExpr
48+ ( fromPrimExpr, toPrimExpr
40− , traversePrimExpr
49+ , scastExpr, traverseFieldP
41− , fromColumn, toColumn
42 )
50 )
43−import Rel8.Kind.Necessity ( SNecessity( SRequired, SOptional ) )
44−import Rel8.Schema.Context ( Col, Col'(..), Insertion, Name(..) )
45−import Rel8.Schema.HTable ( htabulateA, hfield, htraverse, hspecs )
51+import Rel8.Schema.HTable ( htabulateA, hfield, hspecs, htabulate,
52+ htraverseP, htraversePWithField )
46−import Rel8.Schema.Spec ( SSpec(..) )
53+import Rel8.Schema.Name ( Name( Name ), Selects, ppColumn )
54+import Rel8.Schema.Spec ( Spec(..) )
47−import Rel8.Schema.Table ( TableSchema(..) )
55+import Rel8.Schema.Table ( TableSchema(..), ppTable )
48import Rel8.Table ( Table, fromColumns, toColumns )
56import Rel8.Table ( Table, fromColumns, toColumns )
49−import Rel8.Table.Recontextualize ( Selects, Inserts )
57+import Rel8.Type.Information ( typeName )
50−import Rel8.Table.Undefined ( undefined )
51
58
52-- semigroupoids
59-- semigroupoids
53import Data.Functor.Apply ( WrappedApplicative(..) )
60import Data.Functor.Apply ( WrappedApplicative(..) )
61+import Data.Profunctor.Product ( ProductProfunctor )
62+
63+
64+aggregator :: Aggregates aggregates exprs => Opaleye.Aggregator aggregates exprs
65+aggregator = dimap toColumns fromColumns $
66+ htraverseP $
67+ lmap (\(Aggregate a) -> (a, ())) Opaleye.aggregatorApply
68+
54
69
70+attributes :: Selects names exprs => TableSchema names -> exprs
71+attributes schema@TableSchema {columns} = fromColumns $ htabulate $ \field ->
72+ case hfield (toColumns columns) field of
73+ Name column -> fromPrimExpr $ Opaleye.ConstExpr $
74+ Opaleye.OtherLit $
75+ show (ppTable schema) <> "." <> show (ppColumn column)
55
76
56−aggregator :: Opaleye.Aggregator (Aggregate exprs) exprs
77+
57−aggregator = Opaleye.Aggregator $ Opaleye.PackMap $
78+fromOpaleyespec :: (ProductProfunctor p, Table Expr a)
58− \f (Aggregate (Opaleye.Aggregator (Opaleye.PackMap inner))) -> inner f ()
79+ => p (Opaleye.Field_ n x) (Opaleye.Field_ n x)
80+ -> p a a
81+fromOpaleyespec x =
82+ dimap toColumns fromColumns (htraverseP (traverseFieldP x))
59
83
60
84
61binaryspec :: Table Expr a => Opaleye.Binaryspec a a
85binaryspec :: Table Expr a => Opaleye.Binaryspec a a
62−binaryspec = Opaleye.Binaryspec $ Opaleye.PackMap $ \f (as, bs) ->
86+binaryspec = fromOpaleyespec Opaleye.binaryspecField
63− fmap fromColumns $ unwrapApplicative $ htabulateA $ \field ->
64− WrapApplicative $
65− case (hfield (toColumns as) field, hfield (toColumns bs) field) of
66− (DB a, DB b) -> DB . fromPrimExpr <$> f (toPrimExpr a, toPrimExpr b)
67
87
68
88
69distinctspec :: Table Expr a => Opaleye.Distinctspec a a
89distinctspec :: Table Expr a => Opaleye.Distinctspec a a
70−distinctspec =
90+distinctspec = fromOpaleyespec Opaleye.distinctspecField
71− Opaleye.Distinctspec $ Opaleye.Aggregator $ Opaleye.PackMap $ \f ->
91+
72− fmap fromColumns .
92+
73− unwrapApplicative .
93+exprs :: Table Expr a => a -> NonEmpty Opaleye.PrimExpr
74− htraverse
94+exprs (toColumns -> as) = getConst $ htabulateA $ \field ->
75− (\(DB a) ->
95+ case hfield as field of
76− WrapApplicative $ DB . fromPrimExpr <$> f (Nothing, toPrimExpr a)) .
96+ expr -> Const (pure (toPrimExpr expr))
77− toColumns
97+
78−
98+
79−
99+exprsWithNames :: Selects names exprs
80−table ::(Selects names exprs, Inserts exprs inserts)
100+ => names -> exprs -> NonEmpty (String, Opaleye.PrimExpr)
101+exprsWithNames names as = getConst $ htabulateA $ \field ->
102+ case (hfield (toColumns names) field, hfield (toColumns as) field) of
103+ (Name name, expr) -> Const (pure (name, toPrimExpr expr))
104+
105+
81− => TableSchema names -> Opaleye.Table inserts exprs
106+table :: Selects names exprs => TableSchema names -> Opaleye.Table exprs exprs
82table (TableSchema name schema columns) =
107table (TableSchema name schema columns) =
83− Opaleye.Table qualified (tableFields columns)
84− where
85− qualified = case schema of
108+ case schema of
86− Nothing -> name
109+ Nothing -> Opaleye.table name (tableFields columns)
87− Just qualifier -> qualifier <> "." <> name
110+ Just schemaName -> Opaleye.tableWithSchema schemaName name (tableFields columns)
88
111
89
112
90−tableFields :: (Selects names exprs, Inserts exprs inserts)
113+tableFields :: Selects names exprs
91− => names -> Opaleye.TableFields inserts exprs
114+ => names -> Opaleye.TableFields exprs exprs
92tableFields (toColumns -> names) = dimap toColumns fromColumns $
115tableFields (toColumns -> names) = dimap toColumns fromColumns $
93 unwrapApplicative $ htabulateA $ \field -> WrapApplicative $
116 unwrapApplicative $ htabulateA $ \field -> WrapApplicative $
94− case hfield hspecs field of
117+ case hfield names field of
95− specs -> case hfield names field of
96− name -> lmap (`hfield` field) (go specs name)
118+ name -> lmap (`hfield` field) (go name)
97 where
119 where
98− go :: SSpec spec -> Col Name spec -> Opaleye.TableFields (Col Insertion spec) (Col Expr spec)
120+ go :: Name a -> Opaleye.TableFields (Expr a) (Expr a)
99− go SSpec {necessity, info, nullability} (Col (Name name)) =
121+ go (Name name) =
100− case necessity of
122+ traverseFieldP $
101− SRequired ->
102− lmap (\(RequiredInsert a) -> toColumn $ toPrimExpr a) $
103− DB . scastExpr nullability info . fromPrimExpr . fromColumn <$>
104− Opaleye.requiredTableField name
123+ Opaleye.requiredTableField name
105− SOptional ->
106− lmap (\(OptionalInsert ma) -> toColumn . toPrimExpr <$> ma) $
107− DB . scastExpr nullability info . fromPrimExpr . fromColumn <$>
108− Opaleye.optionalTableField name
109
124
110
125
111unpackspec :: Table Expr a => Opaleye.Unpackspec a a
126unpackspec :: Table Expr a => Opaleye.Unpackspec a a
112−unpackspec = Opaleye.Unpackspec $ Opaleye.PackMap $ \f ->
127+unpackspec = fromOpaleyespec Opaleye.unpackspecField
113− fmap fromColumns .
114− unwrapApplicative .
115− htraverse (\(DB a) -> WrapApplicative $ DB <$> traversePrimExpr f a) .
116− toColumns
117{-# INLINABLE unpackspec #-}
128{-# INLINABLE unpackspec #-}
118
129
119
130
120−valuesspec :: Table Expr a => Opaleye.ValuesspecSafe a a
131+valuesspec :: Table Expr a => Opaleye.Valuesspec a a
121−valuesspec = Opaleye.ValuesspecSafe (toPackMap undefined) unpackspec
132+valuesspec = dimap toColumns fromColumns $
133+ htraversePWithField (traverseFieldP . Opaleye.valuesspecFieldType . typeName)
134+ where typeName = Rel8.Type.Information.typeName . info . hfield hspecs
135+
136+
137+view :: Selects names exprs => names -> exprs
138+view columns = fromColumns $ htabulate $ \field ->
139+ case hfield (toColumns columns) field of
140+ Name column -> fromPrimExpr $ Opaleye.BaseTableAttrExpr column
122
141
123
142
143+-- | Transform a table by adding 'CAST' to all columns. This is most useful for
144+-- finalising a SELECT or RETURNING statement, guaranteed that the output
145+-- matches what is encoded in each columns TypeInformation.
124−toPackMap :: Table Expr a
146+castTable :: Table Expr a => a -> a
125− => a -> Opaleye.PackMap Opaleye.PrimExpr Opaleye.PrimExpr () a
147+castTable (toColumns -> as) = fromColumns $ htabulate \field ->
126−toPackMap as = Opaleye.PackMap $ \f () ->
148+ case hfield hspecs field of
127− fmap fromColumns $
149+ Spec {info} -> case hfield as field of
128− unwrapApplicative .
150+ expr -> scastExpr info expr
129− htraverse (\(DB a) -> WrapApplicative $ DB <$> traversePrimExpr f a) $
130− toColumns as
src/Rel8/Table/Ord.hs+70−49
@@ -1,40 +1,41 @@
1+{-# language AllowAmbiguousTypes #-}
1{-# language DataKinds #-}
2{-# language DataKinds #-}
3+{-# language DefaultSignatures #-}
4+{-# language DisambiguateRecordFields #-}
5+{-# language FlexibleContexts #-}
2{-# language FlexibleInstances #-}
6{-# language FlexibleInstances #-}
3−{-# language NamedFieldPuns #-}
4{-# language ScopedTypeVariables #-}
7{-# language ScopedTypeVariables #-}
5{-# language StandaloneKindSignatures #-}
8{-# language StandaloneKindSignatures #-}
6{-# language TypeApplications #-}
9{-# language TypeApplications #-}
7{-# language TypeFamilies #-}
10{-# language TypeFamilies #-}
11+{-# language TypeOperators #-}
8{-# language UndecidableInstances #-}
12{-# language UndecidableInstances #-}
9−{-# language UndecidableSuperClasses #-}
10{-# language ViewPatterns #-}
13{-# language ViewPatterns #-}
11
14
12module Rel8.Table.Ord
15module Rel8.Table.Ord
13− ( OrdTable, (<:), (<=:), (>:), (>=:), least, greatest
16+ ( OrdTable( ordTable ), (<:), (<=:), (>:), (>=:), least, greatest
14 )
17 )
15where
18where
16
19
17-- base
20-- base
18import Data.Functor.Const ( Const( Const ), getConst )
21import Data.Functor.Const ( Const( Const ), getConst )
19import Data.Kind ( Constraint, Type )
22import Data.Kind ( Constraint, Type )
23+import GHC.Generics ( Rep )
20import Prelude hiding ( seq )
24import Prelude hiding ( seq )
21
25
22-- rel8
26-- rel8
23import Rel8.Expr ( Expr )
27import Rel8.Expr ( Expr )
24import Rel8.Expr.Bool ( (||.), (&&.), false, true )
28import Rel8.Expr.Bool ( (||.), (&&.), false, true )
25−import Rel8.Expr.Eq ( seq )
29+import Rel8.Expr.Eq ( (==.) )
26−import Rel8.Expr.Ord ( slt, sgt)
30+import Rel8.Expr.Ord ( (<.), (>.) )
27−import Rel8.Opaque ( Opaque )
31+import Rel8.FCF ( Eval, Exp )
28−import Rel8.Schema.Context ( Col'(..) )
32+import Rel8.Generic.Record ( Record )
33+import Rel8.Generic.Table.Record ( GTable, GColumns, gtable )
29import Rel8.Schema.Dict ( Dict( Dict ) )
34import Rel8.Schema.Dict ( Dict( Dict ) )
30−import Rel8.Schema.HTable
35+import Rel8.Schema.HTable ( htabulateA, hfield )
31− ( HConstrainTable
32− , htabulateA, hfield
33− , hdicts, hspecs
34− )
35−import Rel8.Schema.Spec ( SSpec(..) )
36+import Rel8.Schema.HTable.Identity ( HIdentity( HIdentity ) )
36−import Rel8.Schema.Spec.ConstrainDBType ( ConstrainDBType )
37+import Rel8.Schema.Null (Sql)
37−import Rel8.Table ( Columns, toColumns )
38+import Rel8.Table ( Columns, toColumns, TColumns )
38import Rel8.Table.Bool ( bool )
39import Rel8.Table.Bool ( bool )
39import Rel8.Table.Eq ( EqTable )
40import Rel8.Table.Eq ( EqTable )
40import Rel8.Type.Ord ( DBOrd )
41import Rel8.Type.Ord ( DBOrd )
@@ -44,15 +45,51 @@ import Rel8.Type.Ord ( DBOrd )
44-- by their lexicographic ordering of all columns, so this class means "all
45-- by their lexicographic ordering of all columns, so this class means "all
45-- columns in a 'Table' have an instance of 'DBOrd'".
46-- columns in a 'Table' have an instance of 'DBOrd'".
46type OrdTable :: Type -> Constraint
47type OrdTable :: Type -> Constraint
47−class
48− ( EqTable a
48+class EqTable a => OrdTable a where
49− , HConstrainTable (Columns a) (ConstrainDBType DBOrd)
49+ ordTable :: Columns a (Dict (Sql DBOrd))
50− ) => OrdTable a
50+
51+ default ordTable ::
52+ ( GTable TOrdTable TColumns (Rep (Record a))
53+ , Columns a ~ GColumns TColumns (Rep (Record a))
54+ )
55+ => Columns a (Dict (Sql DBOrd))
56+ ordTable = gtable @TOrdTable @TColumns @(Rep (Record a)) table
57+ where
58+ table (_ :: proxy x) = ordTable @x
59+
60+
61+data TOrdTable :: Type -> Exp Constraint
62+type instance Eval (TOrdTable a) = OrdTable a
63+
64+
65+instance Sql DBOrd a => OrdTable (Expr a) where
66+ ordTable = HIdentity Dict
67+
68+
69+instance (OrdTable a, OrdTable b) => OrdTable (a, b)
70+
71+
72+instance (OrdTable a, OrdTable b, OrdTable c) => OrdTable (a, b, c)
73+
74+
75+instance (OrdTable a, OrdTable b, OrdTable c, OrdTable d) => OrdTable (a, b, c, d)
76+
77+
78+instance (OrdTable a, OrdTable b, OrdTable c, OrdTable d, OrdTable e) =>
79+ OrdTable (a, b, c, d, e)
80+
81+
51instance
82instance
52− ( EqTable a
83+ ( OrdTable a, OrdTable b, OrdTable c, OrdTable d, OrdTable e, OrdTable f
53− , HConstrainTable (Columns a) (ConstrainDBType DBOrd)
84+ )
54− ) => OrdTable a
85+ => OrdTable (a, b, c, d, e, f)
55−instance {-# OVERLAPPING #-} OrdTable Opaque
86+
87+
88+instance
89+ ( OrdTable a, OrdTable b, OrdTable c, OrdTable d, OrdTable e, OrdTable f
90+ , OrdTable g
91+ )
92+ => OrdTable (a, b, c, d, e, f, g)
56
93
57
94
58-- | Test if one 'Table' sorts before another. Corresponds to comparing all
95-- | Test if one 'Table' sorts before another. Corresponds to comparing all
@@ -61,13 +98,9 @@ instance {-# OVERLAPPING #-} OrdTable Opaque
61(toColumns -> as) <: (toColumns -> bs) =
98(toColumns -> as) <: (toColumns -> bs) =
62 foldr @[] go false $ getConst $ htabulateA $ \field ->
99 foldr @[] go false $ getConst $ htabulateA $ \field ->
63 case (hfield as field, hfield bs field) of
100 case (hfield as field, hfield bs field) of
64− (DB a, DB b) -> case hfield dicts field of
101+ (a, b) -> case hfield (ordTable @a) field of
65− Dict -> case hfield specs field of
102+ Dict -> Const [(a <. b, a ==. b)]
66− SSpec {nullability} ->
67− Const [(slt nullability a b, seq nullability a b)]
68 where
103 where
69− dicts = hdicts @(Columns a) @(ConstrainDBType DBOrd)
70− specs = hspecs @(Columns a)
71 go (lt, eq) a = lt ||. (eq &&. a)
104 go (lt, eq) a = lt ||. (eq &&. a)
72infix 4 <:
105infix 4 <:
73
106
@@ -78,13 +111,9 @@ infix 4 <:
78(toColumns -> as) <=: (toColumns -> bs) =
111(toColumns -> as) <=: (toColumns -> bs) =
79 foldr @[] go true $ getConst $ htabulateA $ \field ->
112 foldr @[] go true $ getConst $ htabulateA $ \field ->
80 case (hfield as field, hfield bs field) of
113 case (hfield as field, hfield bs field) of
81− (DB a, DB b) -> case hfield dicts field of
114+ (a, b) -> case hfield (ordTable @a) field of
82− Dict -> case hfield specs field of
115+ Dict -> Const [(a <. b, a ==. b)]
83− SSpec {nullability} ->
84− Const [(slt nullability a b, seq nullability a b)]
85 where
116 where
86− dicts = hdicts @(Columns a) @(ConstrainDBType DBOrd)
87− specs = hspecs @(Columns a)
88 go (lt, eq) a = lt ||. (eq &&. a)
117 go (lt, eq) a = lt ||. (eq &&. a)
89infix 4 <=:
118infix 4 <=:
90
119
@@ -95,13 +124,9 @@ infix 4 <=:
95(toColumns -> as) >: (toColumns -> bs) =
124(toColumns -> as) >: (toColumns -> bs) =
96 foldr @[] go false $ getConst $ htabulateA $ \field ->
125 foldr @[] go false $ getConst $ htabulateA $ \field ->
97 case (hfield as field, hfield bs field) of
126 case (hfield as field, hfield bs field) of
98− (DB a, DB b) -> case hfield dicts field of
127+ (a, b) -> case hfield (ordTable @a) field of
99− Dict -> case hfield specs field of
128+ Dict -> Const [(a >. b, a ==. b)]
100− SSpec {nullability} ->
101− Const [(slt nullability a b, seq nullability a b)]
102 where
129 where
103− dicts = hdicts @(Columns a) @(ConstrainDBType DBOrd)
104− specs = hspecs @(Columns a)
105 go (gt, eq) a = gt ||. (eq &&. a)
130 go (gt, eq) a = gt ||. (eq &&. a)
106infix 4 >:
131infix 4 >:
107
132
@@ -112,22 +137,18 @@ infix 4 >:
112(toColumns -> as) >=: (toColumns -> bs) =
137(toColumns -> as) >=: (toColumns -> bs) =
113 foldr @[] go true $ getConst $ htabulateA $ \field ->
138 foldr @[] go true $ getConst $ htabulateA $ \field ->
114 case (hfield as field, hfield bs field) of
139 case (hfield as field, hfield bs field) of
115− (DB a, DB b) -> case hfield dicts field of
140+ (a, b) -> case hfield (ordTable @a) field of
116− Dict -> case hfield specs field of
141+ Dict -> Const [(a >. b, a ==. b)]
117− SSpec {nullability} ->
118− Const [(sgt nullability a b, seq nullability a b)]
119 where
142 where
120− dicts = hdicts @(Columns a) @(ConstrainDBType DBOrd)
121− specs = hspecs @(Columns a)
122 go (gt, eq) a = gt ||. (eq &&. a)
143 go (gt, eq) a = gt ||. (eq &&. a)
123infix 4 >=:
144infix 4 >=:
124
145
125
146
126-- | Given two 'Table's, return the table that sorts before the other.
147-- | Given two 'Table's, return the table that sorts before the other.
127least :: OrdTable a => a -> a -> a
148least :: OrdTable a => a -> a -> a
128−least a b = bool a b (a <: b)
149+least a b = bool b a (a <: b)
129
150
130
151
131-- | Given two 'Table's, return the table that sorts after the other.
152-- | Given two 'Table's, return the table that sorts after the other.
132greatest :: OrdTable a => a -> a -> a
153greatest :: OrdTable a => a -> a -> a
133−greatest a b = bool a b (a >: b)
154+greatest a b = bool b a (a >: b)
src/Rel8/Table/Order.hs+16−20
@@ -1,3 +1,4 @@
1+{-# language DataKinds #-}
1{-# language NamedFieldPuns #-}
2{-# language NamedFieldPuns #-}
2{-# language ScopedTypeVariables #-}
3{-# language ScopedTypeVariables #-}
3{-# language TypeApplications #-}
4{-# language TypeApplications #-}
@@ -17,15 +18,12 @@ import Prelude
17-- rel8
18-- rel8
18import Rel8.Expr.Order ( asc, desc, nullsFirst, nullsLast )
19import Rel8.Expr.Order ( asc, desc, nullsFirst, nullsLast )
19import Rel8.Order ( Order )
20import Rel8.Order ( Order )
20−import Rel8.Schema.Context ( unDB )
21import Rel8.Schema.Dict ( Dict( Dict ) )
21import Rel8.Schema.Dict ( Dict( Dict ) )
22−import Rel8.Schema.HTable (htabulateA, hfield, hdicts, hspecs)
22+import Rel8.Schema.HTable (htabulateA, hfield, hspecs)
23−import Rel8.Schema.Nullability ( Nullability( Nullable, NonNullable ) )
23+import Rel8.Schema.Null ( Nullity( Null, NotNull ) )
24−import Rel8.Schema.Spec ( SSpec(..) )
24+import Rel8.Schema.Spec ( Spec( Spec, nullity ) )
25−import Rel8.Schema.Spec.ConstrainDBType ( ConstrainDBType )
25+import Rel8.Table ( Columns, toColumns )
26−import Rel8.Table
26+import Rel8.Table.Ord ( OrdTable, ordTable )
27−import Rel8.Table.Ord
28−import Rel8.Type.Ord
29
27
30
28
31-- | Construct an 'Order' for a 'Table' by sorting all columns into ascending
29-- | Construct an 'Order' for a 'Table' by sorting all columns into ascending
@@ -33,12 +31,11 @@ import Rel8.Type.Ord
33ascTable :: forall a. OrdTable a => Order a
31ascTable :: forall a. OrdTable a => Order a
34ascTable = contramap toColumns $ getConst $
32ascTable = contramap toColumns $ getConst $
35 htabulateA @(Columns a) $ \field -> case hfield hspecs field of
33 htabulateA @(Columns a) $ \field -> case hfield hspecs field of
36− SSpec {nullability} -> case hfield ords field of
34+ Spec {nullity} -> case hfield (ordTable @a) field of
37− Dict -> Const $ unDB . (`hfield` field) >$< case nullability of
35+ Dict -> Const $ (`hfield` field) >$<
36+ case nullity of
38− Nullable -> nullsFirst asc
37+ Null -> nullsFirst asc
39− NonNullable -> asc
38+ NotNull -> asc
40− where
41− ords = hdicts @(Columns a) @(ConstrainDBType DBOrd)
42
39
43
40
44-- | Construct an 'Order' for a 'Table' by sorting all columns into descending
41-- | Construct an 'Order' for a 'Table' by sorting all columns into descending
@@ -46,9 +43,8 @@ ascTable = contramap toColumns $ getConst $
46descTable :: forall a. OrdTable a => Order a
43descTable :: forall a. OrdTable a => Order a
47descTable = contramap toColumns $ getConst $
44descTable = contramap toColumns $ getConst $
48 htabulateA @(Columns a) $ \field -> case hfield hspecs field of
45 htabulateA @(Columns a) $ \field -> case hfield hspecs field of
49− SSpec {nullability} -> case hfield ords field of
46+ Spec {nullity} -> case hfield (ordTable @a) field of
50− Dict -> Const $ unDB . (`hfield` field) >$< case nullability of
47+ Dict -> Const $ (`hfield` field) >$<
48+ case nullity of
51− Nullable -> nullsLast desc
49+ Null -> nullsLast desc
52− NonNullable -> desc
50+ NotNull -> desc
53− where
54− ords = hdicts @(Columns a) @(ConstrainDBType DBOrd)
src/Rel8/Table/Projection.hsnew file+73
@@ -0,0 +1,73 @@
1+{-# language FlexibleContexts #-}
2+{-# language FlexibleInstances #-}
3+{-# language MonoLocalBinds #-}
4+{-# language MultiParamTypeClasses #-}
5+{-# language StandaloneKindSignatures #-}
6+{-# language UndecidableInstances #-}
7+
8+module Rel8.Table.Projection
9+ ( Projection
10+ , Projectable( project )
11+ , Biprojectable( biproject )
12+ , Projecting
13+ , apply
14+ )
15+where
16+
17+-- base
18+import Data.Kind ( Constraint, Type )
19+import Prelude
20+
21+-- rel8
22+import Rel8.Schema.Field ( Field( Field ), fields )
23+import Rel8.Schema.HTable ( hfield, htabulate )
24+import Rel8.Table ( Columns, Context, Transpose, toColumns )
25+import Rel8.Table.Transpose ( Transposes )
26+
27+
28+-- | The constraint @'Projecting' a b@ ensures that @'Projection' a b@ is a
29+-- usable 'Projection'.
30+type Projecting :: Type -> Type -> Constraint
31+class
32+ ( Transposes (Context a) (Field a) a (Transpose (Field a) a)
33+ , Transposes (Context a) (Field a) b (Transpose (Field a) b)
34+ )
35+ => Projecting a b
36+instance
37+ ( Transposes (Context a) (Field a) a (Transpose (Field a) a)
38+ , Transposes (Context a) (Field a) b (Transpose (Field a) b)
39+ )
40+ => Projecting a b
41+
42+
43+-- | A @'Projection' a b@s is a special type of function @a -> b@ whereby the
44+-- resulting @b@ is guaranteed to be composed only from columns contained in
45+-- @a@.
46+type Projection :: Type -> Type -> Type
47+type Projection a b = Transpose (Field a) a -> Transpose (Field a) b
48+
49+
50+-- | @'Projectable' f@ means that @f@ is a kind of functor on 'Rel8.Table's
51+-- that allows the mapping of a 'Projection' over its underlying columns.
52+type Projectable :: (Type -> Type) -> Constraint
53+class Projectable f where
54+ -- | Map a 'Projection' over @f@.
55+ project :: Projecting a b
56+ => Projection a b -> f a -> f b
57+
58+
59+-- | @'Biprojectable' p@ means that @p@ is a kind of bifunctor on
60+-- 'Rel8.Table's that allows the mapping of a pair of 'Projection's over its
61+-- underlying columns.
62+type Biprojectable :: (Type -> Type -> Type) -> Constraint
63+class Biprojectable p where
64+ -- | Map a pair of 'Projection's over @p@.
65+ biproject :: (Projecting a b, Projecting c d)
66+ => Projection a b -> Projection c d -> p a c -> p b d
67+
68+
69+apply :: Projecting a b
70+ => Projection a b -> Columns a context -> Columns b context
71+apply f a = case toColumns (f fields) of
72+ bs -> htabulate $ \field -> case hfield bs field of
73+ Field field' -> hfield a field'
src/Rel8/Table/Recontextualize.hsdeleted−213
@@ -1,213 +0,0 @@
1−{-# language DataKinds #-}
2−{-# language FlexibleContexts #-}
3−{-# language FlexibleInstances #-}
4−{-# language FunctionalDependencies #-}
5−{-# language StandaloneKindSignatures #-}
6−{-# language TypeFamilies #-}
7−{-# language UndecidableInstances #-}
8−{-# language UndecidableSuperClasses #-}
9−
10−module Rel8.Table.Recontextualize
11− ( Recontextualize
12− , Aggregates
13− , Encodes
14− , Selects
15− , Inserts
16− )
17−where
18−
19−-- base
20−import Data.Functor.Identity ( Identity )
21−import Data.Kind ( Constraint, Type )
22−import Prelude ()
23−
24−-- rel8
25−import Rel8.Aggregate ( Aggregate )
26−import Rel8.Expr ( Expr )
27−import Rel8.Opaque ( Opaque, Opaque1 )
28−import Rel8.Schema.Context ( Col', Insertion, Name, IsSpecialContext )
29−import Rel8.Schema.Context.Label ( Labelable )
30−import Rel8.Schema.HTable ( HTable )
31−import qualified Rel8.Schema.Kind as K
32−import Rel8.Schema.Nullability ( Sql )
33−import Rel8.Schema.Spec ( KnownSpec )
34−import Rel8.Table ( Table, Congruent )
35−import Rel8.Type ( DBType )
36−
37−
38−type Recontextualize :: K.Context -> K.Context -> Type -> Type -> Constraint
39−class
40− ( Table from a
41− , Table to b
42− , Congruent a b
43− , Recontextualize from from a a
44− , Recontextualize to to b b
45− , Recontextualize to from b a
46− ) => Recontextualize from to a b
47− | a -> from
48− , b -> to
49− , a to -> b
50− , b from -> a
51−
52−
53−instance (KnownSpec spec, x ~ IsSpecialContext from, y ~ IsSpecialContext to) =>
54− Recontextualize from to (Col' x from spec) (Col' y to spec)
55−
56−
57−instance Sql DBType a =>
58− Recontextualize Aggregate Aggregate (Aggregate (Expr a)) (Aggregate (Expr a))
59−
60−
61−instance Sql DBType a =>
62− Recontextualize Aggregate Expr (Aggregate (Expr a)) (Expr a)
63−
64−
65−instance Sql DBType a =>
66− Recontextualize Aggregate Identity (Aggregate (Expr a)) (Identity a)
67−
68−
69−instance Sql DBType a =>
70− Recontextualize Aggregate Insertion (Aggregate (Expr a)) (Insertion a)
71−
72−
73−instance Sql DBType a =>
74− Recontextualize Aggregate Name (Aggregate (Expr a)) (Name a)
75−
76−
77−instance Sql DBType a =>
78− Recontextualize Expr Aggregate (Expr a) (Aggregate (Expr a))
79−
80−
81−instance Sql DBType a => Recontextualize Expr Expr (Expr a) (Expr a)
82−
83−
84−instance Sql DBType a => Recontextualize Expr Identity (Expr a) (Identity a)
85−
86−
87−instance Sql DBType a => Recontextualize Expr Insertion (Expr a) (Insertion a)
88−
89−
90−instance Sql DBType a => Recontextualize Expr Name (Expr a) (Name a)
91−
92−
93−instance Sql DBType a =>
94− Recontextualize Identity Aggregate (Identity a) (Aggregate (Expr a))
95−
96−
97−instance Sql DBType a => Recontextualize Identity Expr (Identity a) (Expr a)
98−
99−
100−instance Sql DBType a => Recontextualize Identity Identity (Identity a) (Identity a)
101−
102−
103−instance Sql DBType a =>
104− Recontextualize Identity Insertion (Identity a) (Insertion a)
105−
106−
107−instance Sql DBType a => Recontextualize Identity Name (Identity a) (Name a)
108−
109−
110−instance Sql DBType a =>
111− Recontextualize Insertion Aggregate (Insertion a) (Aggregate (Expr a))
112−
113−
114−instance Sql DBType a => Recontextualize Insertion Expr (Insertion a) (Expr a)
115−
116−
117−instance Sql DBType a =>
118− Recontextualize Insertion Identity (Insertion a) (Identity a)
119−
120−
121−instance Sql DBType a => Recontextualize Insertion Insertion (Insertion a) (Insertion a)
122−
123−
124−instance Sql DBType a => Recontextualize Insertion Name (Insertion a) (Name a)
125−
126−
127−instance Sql DBType a =>
128− Recontextualize Name Aggregate (Name a) (Aggregate (Expr a))
129−
130−
131−instance Sql DBType a => Recontextualize Name Expr (Name a) (Expr a)
132−
133−
134−instance Sql DBType a => Recontextualize Name Identity (Name a) (Identity a)
135−
136−
137−instance Sql DBType a => Recontextualize Name Insertion (Name a) (Insertion a)
138−
139−
140−instance Sql DBType a => Recontextualize Name Name (Name a) (Name a)
141−
142−
143−instance Recontextualize from to (Opaque1 from a) (Opaque1 to a)
144−
145−
146−instance (HTable t, x ~ IsSpecialContext from, y ~ IsSpecialContext to) =>
147− Recontextualize from to (t (Col' x from)) (t (Col' y to))
148−
149−
150−instance
151− ( Table from (t from)
152− , Table to (t to)
153− , Congruent (t from) (t to)
154− ) => Recontextualize from to (t from) (t to)
155−
156−
157−instance
158− ( Recontextualize from to a1 b1
159− , Recontextualize from to a2 b2
160− , Labelable from
161− , Labelable to
162− ) => Recontextualize from to (a1, a2) (b1, b2)
163−
164−
165−instance
166− ( Recontextualize from to a1 b1
167− , Recontextualize from to a2 b2
168− , Recontextualize from to a3 b3
169− , Labelable from, Labelable to
170− ) => Recontextualize from to (a1, a2, a3) (b1, b2, b3)
171−
172−
173−instance
174− ( Recontextualize from to a1 b1
175− , Recontextualize from to a2 b2
176− , Recontextualize from to a3 b3
177− , Recontextualize from to a4 b4
178− , Labelable from, Labelable to
179− ) => Recontextualize from to (a1, a2, a3, a4) (b1, b2, b3, b4)
180−
181−
182−instance
183− ( Recontextualize from to a1 b1
184− , Recontextualize from to a2 b2
185− , Recontextualize from to a3 b3
186− , Recontextualize from to a4 b4
187− , Recontextualize from to a5 b5
188− , Labelable from, Labelable to
189− ) => Recontextualize from to (a1, a2, a3, a4, a5) (b1, b2, b3, b4, b5)
190−
191−
192−type Aggregates :: Type -> Type -> Constraint
193−class Recontextualize Aggregate Expr aggregates exprs => Aggregates aggregates exprs
194−instance Recontextualize Aggregate Expr aggregates exprs => Aggregates aggregates exprs
195−instance {-# OVERLAPPING #-} Aggregates (Opaque1 Aggregate Opaque) (Opaque1 Expr Opaque)
196−
197−
198−type Encodes :: Type -> Type -> Constraint
199−class Recontextualize Identity Expr a exprs => Encodes a exprs
200−instance Recontextualize Identity Expr a exprs => Encodes a exprs
201−instance {-# OVERLAPPING #-} Encodes (Opaque1 Identity Opaque) (Opaque1 Expr Opaque)
202−
203−
204−type Inserts :: Type -> Type -> Constraint
205−class Recontextualize Expr Insertion exprs inserts => Inserts exprs inserts
206−instance Recontextualize Expr Insertion exprs inserts => Inserts exprs inserts
207−instance {-# OVERLAPPING #-} Inserts (Opaque1 Expr Opaque) (Opaque1 Insertion Opaque)
208−
209−
210−type Selects :: Type -> Type -> Constraint
211−class Recontextualize Name Expr names exprs => Selects names exprs
212−instance Recontextualize Name Expr names exprs => Selects names exprs
213−instance {-# OVERLAPPING #-} Selects (Opaque1 Name Opaque) (Opaque1 Expr Opaque)
src/Rel8/Table/Rel8able.hsnew file+92
@@ -0,0 +1,92 @@
1+{-# language DataKinds #-}
2+{-# language FlexibleInstances #-}
3+{-# language MultiParamTypeClasses #-}
4+{-# language ScopedTypeVariables #-}
5+{-# language StandaloneKindSignatures #-}
6+{-# language TypeApplications #-}
7+{-# language TypeFamilies #-}
8+{-# language UndecidableInstances #-}
9+
10+{-# options_ghc -fno-warn-orphans #-}
11+
12+module Rel8.Table.Rel8able
13+ (
14+ )
15+where
16+
17+-- base
18+import Prelude ()
19+
20+-- rel8
21+import Rel8.Expr ( Expr )
22+import qualified Rel8.Kind.Algebra as K
23+import Rel8.Kind.Context ( Reifiable, contextSing )
24+import Rel8.Generic.Rel8able
25+ ( Rel8able, Algebra
26+ , GColumns, gfromColumns, gtoColumns
27+ , GFromExprs, gfromResult, gtoResult
28+ )
29+import qualified Rel8.Schema.Kind as K
30+import Rel8.Schema.HTable ( HConstrainTable, hdicts )
31+import Rel8.Schema.Null ( Sql )
32+import Rel8.Schema.Result ( Result )
33+import Rel8.Table
34+ ( Table, Columns, Context, fromColumns, toColumns
35+ , FromExprs, fromResult, toResult
36+ , Transpose
37+ )
38+import Rel8.Table.ADT ( ADT )
39+import Rel8.Table.Eq ( EqTable, eqTable )
40+import Rel8.Table.Ord ( OrdTable, ordTable )
41+import Rel8.Table.Serialize ( ToExprs )
42+import Rel8.Type.Eq ( DBEq )
43+import Rel8.Type.Ord ( DBOrd )
44+
45+
46+instance (Rel8able t, Reifiable context, context ~ context') =>
47+ Table context' (t context)
48+ where
49+ type Columns (t context) = GColumns t
50+ type Context (t context) = context
51+ type FromExprs (t context) = GFromExprs t
52+ type Transpose to (t context) = t to
53+
54+ fromColumns = gfromColumns contextSing
55+ toColumns = gtoColumns contextSing
56+ fromResult = gfromResult @t
57+ toResult = gtoResult @t
58+
59+
60+instance
61+ ( context ~ Expr
62+ , Rel8able t
63+ , HConstrainTable (Columns (t context)) (Sql DBEq)
64+ )
65+ => EqTable (t context)
66+ where
67+ eqTable = hdicts @(Columns (t context)) @(Sql DBEq)
68+
69+
70+instance
71+ ( context ~ Expr
72+ , Rel8able t
73+ , HConstrainTable (Columns (t context)) (Sql DBEq)
74+ , HConstrainTable (Columns (t context)) (Sql DBOrd)
75+ )
76+ => OrdTable (t context)
77+ where
78+ ordTable = hdicts @(Columns (t context)) @(Sql DBOrd)
79+
80+
81+instance
82+ ( Rel8able t', t' ~ Choose (Algebra t) t
83+ , x ~ t' Expr
84+ , result ~ Result
85+ )
86+ => ToExprs x (t result)
87+
88+
89+type Choose :: K.Algebra -> K.Rel8able -> K.Rel8able
90+type family Choose algebra t where
91+ Choose 'K.Sum t = ADT t
92+ Choose 'K.Product t = t
src/Rel8/Table/Serialize.hs+69−373
@@ -1,6 +1,4 @@
1{-# language AllowAmbiguousTypes #-}
1{-# language AllowAmbiguousTypes #-}
2−{-# language DataKinds #-}
3−{-# language DisambiguateRecordFields #-}
4{-# language FlexibleContexts #-}
2{-# language FlexibleContexts #-}
5{-# language FlexibleInstances #-}
3{-# language FlexibleInstances #-}
6{-# language FunctionalDependencies #-}
4{-# language FunctionalDependencies #-}
@@ -9,17 +7,16 @@
9{-# language StandaloneKindSignatures #-}
7{-# language StandaloneKindSignatures #-}
10{-# language TypeApplications #-}
8{-# language TypeApplications #-}
11{-# language TypeFamilies #-}
9{-# language TypeFamilies #-}
12−{-# language ViewPatterns #-}
13{-# language UndecidableInstances #-}
10{-# language UndecidableInstances #-}
14
11
15module Rel8.Table.Serialize
12module Rel8.Table.Serialize
16− ( Serializable, lit, parse
13+ ( Serializable, lit, litHTable, parse
14+ , ToExprs
17 )
15 )
18where
16where
19
17
20-- base
18-- base
21−import Data.Bifunctor ( bimap )
22−import Data.Functor.Identity ( Identity )
19+import Data.Functor.Identity ( Identity( Identity ) )
23import Data.Kind ( Constraint, Type )
20import Data.Kind ( Constraint, Type )
24import Data.List.NonEmpty ( NonEmpty )
21import Data.List.NonEmpty ( NonEmpty )
25import Prelude
22import Prelude
@@ -30,423 +27,122 @@ import qualified Hasql.Decoders as Hasql
30-- rel8
27-- rel8
31import Rel8.Expr ( Expr )
28import Rel8.Expr ( Expr )
32import Rel8.Expr.Serialize ( slitExpr, sparseValue )
29import Rel8.Expr.Serialize ( slitExpr, sparseValue )
33−import Rel8.Opaque ( Opaque )
34−import Rel8.Schema.Context ( Col, Col'(..) )
35−import Rel8.Schema.Context.Identity
36− ( fromHEitherTable, toHEitherTable
37− , fromHListTable, toHListTable
38− , fromHMaybeTable, toHMaybeTable
39− , fromHNonEmptyTable, toHNonEmptyTable
40− , fromHTheseTable, toHTheseTable
41− )
42−import Rel8.Schema.Context.Label ( labeler, unlabeler )
43import Rel8.Schema.HTable ( HTable, htabulate, htabulateA, hfield, hspecs )
30import Rel8.Schema.HTable ( HTable, htabulate, htabulateA, hfield, hspecs )
44−import Rel8.Schema.HTable.Label ( hlabel, hunlabel )
31+import Rel8.Schema.Null ( NotNull, Sql )
45−import Rel8.Schema.HTable.Quartet ( HQuartet(..) )
46−import Rel8.Schema.HTable.Quintet ( HQuintet(..) )
47−import Rel8.Schema.HTable.Pair ( HPair(..) )
48−import Rel8.Schema.HTable.Trio ( HTrio(..) )
49−import Rel8.Schema.HTable.Type ( HType(..) )
50−import Rel8.Schema.Nullability ( IsMaybe, Sql )
51−import Rel8.Schema.Spec ( SSpec(..), KnownSpec )
32+import Rel8.Schema.Result ( Result )
33+import Rel8.Schema.Spec ( Spec(..) )
52−import Rel8.Table ( Table, Columns, fromColumns, toColumns )
34+import Rel8.Table ( Table, fromColumns, FromExprs, fromResult, toResult )
53−import Rel8.Table.Either ( EitherTable )
54−import Rel8.Table.List ( ListTable )
55−import Rel8.Table.Maybe ( MaybeTable )
56−import Rel8.Table.NonEmpty ( NonEmptyTable )
57−import Rel8.Table.Recontextualize ( Encodes )
58−import Rel8.Table.These ( TheseTable )
59import Rel8.Type ( DBType )
35import Rel8.Type ( DBType )
60
36
61-- semigroupoids
37-- semigroupoids
62import Data.Functor.Apply ( WrappedApplicative(..) )
38import Data.Functor.Apply ( WrappedApplicative(..) )
63
39
64−-- these
65−import Data.These ( These )
66−
67−
68−type IsPlainColumn :: Type -> Bool
69−type family IsPlainColumn a where
70− IsPlainColumn (Either _ _) = 'False
71− IsPlainColumn [_] = 'False
72− IsPlainColumn (Maybe _) = 'False
73− IsPlainColumn (NonEmpty _) = 'False
74− IsPlainColumn (These _ _) = 'False
75− IsPlainColumn (_, _) = 'False
76− IsPlainColumn (_, _, _) = 'False
77− IsPlainColumn (_, _, _, _) = 'False
78− IsPlainColumn (_, _, _, _, _) = 'False
79− IsPlainColumn (_ Identity) = 'False
80− IsPlainColumn (_ (Col' _ Identity _)) = 'False
81− IsPlainColumn (Identity _) = 'False
82− IsPlainColumn _ = 'True
83−
84−
85−type IsTabular :: Type -> Bool
86−type family IsTabular a where
87− IsTabular (Either _ _) = 'True
88− IsTabular [a] = IsListTabular a
89− IsTabular (Maybe a) = IsMaybeTabular a
90− IsTabular (NonEmpty a) = IsListTabular a
91− IsTabular (These _ _) = 'True
92− IsTabular (_, _) = 'True
93− IsTabular (_, _, _) = 'True
94− IsTabular (_, _, _, _) = 'True
95− IsTabular (_, _, _, _, _) = 'True
96− IsTabular (_ Identity) = 'True
97− IsTabular (_ (Col' _ Identity)) = 'True
98− IsTabular (Col' _ Identity _) = 'True
99− IsTabular _ = 'False
100−
101−
102−type IsTabular' :: Bool -> Type -> Bool
103−type family IsTabular' isTabular exprs where
104− IsTabular' _ (Expr _) = 'False
105− IsTabular' 'False _ = 'False
106− IsTabular' _ _ = 'True
107−
108−
109−type IsMaybeTabular :: Type -> Bool
110−type family IsMaybeTabular a where
111− IsMaybeTabular (Maybe _) = 'True
112− IsMaybeTabular a = IsTabular a
113−
114−
115−type IsListTabular :: Type -> Bool
116−type family IsListTabular a where
117− IsListTabular (Maybe a) = IsMaybeTabular a
118− IsListTabular a = IsTabular a
119−
120
40
41+-- | @ToExprs exprs a@ is evidence that the types @exprs@ and @a@ describe
42+-- essentially the same type, but @exprs@ is in the 'Expr' context, and @a@ is
43+-- a normal Haskell type.
121type ToExprs :: Type -> Type -> Constraint
44type ToExprs :: Type -> Type -> Constraint
122−class ExprsFor (IsPlainColumn a) (IsTabular' (IsTabular a) exprs) a exprs => ToExprs a exprs
123−instance ExprsFor (IsPlainColumn a) (IsTabular' (IsTabular a) exprs) a exprs => ToExprs a exprs
124−
125−
126−fromIdentity' :: forall exprs a. ToExprs a exprs => Columns exprs (Col Identity) -> a
127−fromIdentity' = fromIdentity @(IsPlainColumn a) @_ @_ @exprs
128−
129−
130−toIdentity' :: forall exprs a. ToExprs a exprs => a -> Columns exprs (Col Identity)
131−toIdentity' = toIdentity @(IsPlainColumn a) @_ @_ @exprs
132−
133−
134−type ExprsFor :: Bool -> Bool -> Type -> Type -> Constraint
135−class (Table Expr exprs, isTabular ~ IsTabular a) =>
136− ExprsFor isPlainColumn isTabular a exprs where
137− fromIdentity :: Columns exprs (Col Identity) -> a
138− toIdentity :: a -> Columns exprs (Col Identity)
139−
140−
141−instance
142− ( DBType a
143− , IsMaybe a ~ 'False
144− , IsTabular a ~ 'False
145− , x ~ Expr a
146− )
147− => ExprsFor 'True 'False a x
148− where
149− fromIdentity (HType (Result a)) = a
150− toIdentity = HType . Result
151−
152−
153−instance
154− ( Sql DBType a
155− , IsListTabular a ~ 'False
156− , x ~ [a]
157− ) => ExprsFor 'False 'False [a] (Expr x)
158− where
159− fromIdentity (HType (Result a)) = a
160− toIdentity = HType . Result
161−
162−
163−instance
164− ( Sql DBType a
165− , isTabular ~ 'False
166− , IsMaybe a ~ 'False
167− , IsMaybeTabular a ~ 'False
168− , x ~ Maybe a
169− ) => ExprsFor 'False 'False (Maybe a) (Expr x)
170− where
171− fromIdentity (HType (Result a)) = a
172− toIdentity = HType . Result
173−
174−
175−instance
176− ( Sql DBType a
177− , IsListTabular a ~ 'False
178− , x ~ NonEmpty a
179− ) => ExprsFor 'False 'False (NonEmpty a) (Expr x)
180− where
181− fromIdentity (HType (Result a)) = a
182− toIdentity = HType . Result
183−
184−
185−instance
186− ( ToExprs a exprs
45+class Table Expr exprs => ToExprs exprs a
187− , IsListTabular a ~ 'False
188− ) => ExprsFor 'False 'False [a] (ListTable exprs)
189− where
190− fromIdentity = fmap (fromIdentity' @exprs) . fromHListTable
191− toIdentity = toHListTable . fmap (toIdentity' @exprs)
192−
193−
194−instance
195− ( ToExprs a exprs
196− , IsMaybeTabular a ~ 'False
197− ) => ExprsFor 'False 'False (Maybe a) (MaybeTable exprs)
198− where
199− fromIdentity =
200− fmap (fromIdentity' @exprs . hunlabel unlabeler) .
201− fromHMaybeTable
202− toIdentity =
203− toHMaybeTable .
204− fmap (hlabel labeler . toIdentity' @exprs)
205−
206−
207−instance
208− ( ToExprs a exprs
209− , IsListTabular a ~ 'False
210− ) => ExprsFor 'False 'False (NonEmpty a) (NonEmptyTable exprs)
211− where
212− fromIdentity = fmap (fromIdentity' @exprs) . fromHNonEmptyTable
213− toIdentity = toHNonEmptyTable . fmap (toIdentity' @exprs)
214
46
215
47
216−instance
48+instance {-# OVERLAPPABLE #-} (Sql DBType a, x ~ Expr a) => ToExprs x a
217− ( ToExprs a exprs1
218− , ToExprs b exprs2
219− , isTabular ~ 'True
220− , x ~ EitherTable exprs1 exprs2
221− ) => ExprsFor 'False isTabular (Either a b) x
222− where
223− fromIdentity =
224− bimap
225− (fromIdentity' @exprs1 . hunlabel unlabeler)
226− (fromIdentity' @exprs2 . hunlabel unlabeler) .
227− fromHEitherTable
228− toIdentity =
229− toHEitherTable .
230− bimap
231− (hlabel labeler . toIdentity' @exprs1)
232− (hlabel labeler . toIdentity' @exprs2)
233
49
234
50
235−instance
51+instance (Sql DBType a, x ~ [a]) => ToExprs (Expr x) [a]
236− ( ToExprs a exprs
237− , IsListTabular a ~ 'True
238− , x ~ ListTable exprs
239− ) => ExprsFor 'False 'True [a] x
240− where
241− fromIdentity = fmap (fromIdentity' @exprs) . fromHListTable
242− toIdentity = toHListTable . fmap (toIdentity' @exprs)
243
52
244
53
245−instance
54+instance (Sql DBType a, NotNull a, x ~ Maybe a) => ToExprs (Expr x) (Maybe a)
246− ( ToExprs a exprs
247− , IsMaybeTabular a ~ 'True
248− , x ~ MaybeTable exprs
249− ) => ExprsFor 'False 'True (Maybe a) x
250− where
251− fromIdentity =
252− fmap (fromIdentity' @exprs . hunlabel unlabeler) .
253− fromHMaybeTable
254− toIdentity =
255− toHMaybeTable .
256− fmap (hlabel labeler . toIdentity' @exprs)
257
55
258
56
259−instance
57+instance (Sql DBType a, NotNull a, x ~ NonEmpty a) => ToExprs (Expr x) (NonEmpty a)
260− ( ToExprs a exprs
261− , IsListTabular a ~ 'True
262− , x ~ NonEmptyTable exprs
263− ) => ExprsFor 'False 'True (NonEmpty a) x
264− where
265− fromIdentity = fmap (fromIdentity' @exprs) . fromHNonEmptyTable
266− toIdentity = toHNonEmptyTable . fmap (toIdentity' @exprs)
267
58
268
59
269−instance
270− ( ToExprs a exprs1
271− , ToExprs b exprs2
60+instance (ToExprs exprs1 a, ToExprs exprs2 b, x ~ (exprs1, exprs2)) =>
272− , isTabular ~ 'True
61+ ToExprs x (a, b)
273− , x ~ TheseTable exprs1 exprs2
274− ) => ExprsFor 'False isTabular (These a b) x
275− where
276− fromIdentity =
277− bimap
278− (fromIdentity' @exprs1 . hunlabel unlabeler)
279− (fromIdentity' @exprs2 . hunlabel unlabeler) .
280− fromHTheseTable
281− toIdentity =
282− toHTheseTable .
283− bimap
284− (hlabel labeler . toIdentity' @exprs1)
285− (hlabel labeler . toIdentity' @exprs2)
286
62
287
63
288instance
64instance
289− ( ToExprs a exprs1
65+ ( ToExprs exprs1 a
290− , ToExprs b exprs2
66+ , ToExprs exprs2 b
291− , isTabular ~ 'True
292− , x ~ (exprs1, exprs2)
293− ) => ExprsFor 'False isTabular (a, b) x
294− where
295− fromIdentity (HPair a b) =
296− ( fromIdentity' @exprs1 $ hunlabel unlabeler a
297− , fromIdentity' @exprs2 $ hunlabel unlabeler b
298− )
299− toIdentity (a, b) = HPair
300− { hfst = hlabel labeler $ toIdentity' @exprs1 a
301− , hsnd = hlabel labeler $ toIdentity' @exprs2 b
302− }
303−
304−
305−instance
306− ( ToExprs a exprs1
307− , ToExprs b exprs2
67+ , ToExprs exprs3 c
308− , ToExprs c exprs3
309− , isTabular ~ 'True
310 , x ~ (exprs1, exprs2, exprs3)
68 , x ~ (exprs1, exprs2, exprs3)
311− ) => ExprsFor 'False isTabular (a, b, c) x
69+ )
312− where
70+ => ToExprs x (a, b, c)
313− fromIdentity (HTrio a b c) =
314− ( fromIdentity' @exprs1 $ hunlabel unlabeler a
315− , fromIdentity' @exprs2 $ hunlabel unlabeler b
316− , fromIdentity' @exprs3 $ hunlabel unlabeler c
317− )
318− toIdentity (a, b, c) = HTrio
319− { hfst = hlabel labeler $ toIdentity' @exprs1 a
320− , hsnd = hlabel labeler $ toIdentity' @exprs2 b
321− , htrd = hlabel labeler $ toIdentity' @exprs3 c
322− }
323
71
324
72
325instance
73instance
326− ( ToExprs a exprs1
74+ ( ToExprs exprs1 a
327− , ToExprs b exprs2
75+ , ToExprs exprs2 b
328− , ToExprs c exprs3
76+ , ToExprs exprs3 c
329− , ToExprs d exprs4
77+ , ToExprs exprs4 d
330− , isTabular ~ 'True
331 , x ~ (exprs1, exprs2, exprs3, exprs4)
78 , x ~ (exprs1, exprs2, exprs3, exprs4)
332− ) => ExprsFor 'False isTabular (a, b, c, d) x
79+ )
333− where
80+ => ToExprs x (a, b, c, d)
334− fromIdentity (HQuartet a b c d) =
335− ( fromIdentity' @exprs1 $ hunlabel unlabeler a
336− , fromIdentity' @exprs2 $ hunlabel unlabeler b
337− , fromIdentity' @exprs3 $ hunlabel unlabeler c
338− , fromIdentity' @exprs4 $ hunlabel unlabeler d
339− )
340− toIdentity (a, b, c, d) = HQuartet
341− { hfst = hlabel labeler $ toIdentity' @exprs1 a
342− , hsnd = hlabel labeler $ toIdentity' @exprs2 b
343− , htrd = hlabel labeler $ toIdentity' @exprs3 c
344− , hfrt = hlabel labeler $ toIdentity' @exprs4 d
345− }
346
81
347
82
348instance
83instance
349− ( ToExprs a exprs1
84+ ( ToExprs exprs1 a
350− , ToExprs b exprs2
85+ , ToExprs exprs2 b
351− , ToExprs c exprs3
86+ , ToExprs exprs3 c
352− , ToExprs d exprs4
87+ , ToExprs exprs4 d
353− , ToExprs e exprs5
88+ , ToExprs exprs5 e
354− , isTabular ~ 'True
355 , x ~ (exprs1, exprs2, exprs3, exprs4, exprs5)
89 , x ~ (exprs1, exprs2, exprs3, exprs4, exprs5)
356− ) => ExprsFor 'False isTabular (a, b, c, d, e) x
90+ )
357− where
91+ => ToExprs x (a, b, c, d, e)
358− fromIdentity (HQuintet a b c d e) =
359− ( fromIdentity' @exprs1 $ hunlabel unlabeler a
360− , fromIdentity' @exprs2 $ hunlabel unlabeler b
361− , fromIdentity' @exprs3 $ hunlabel unlabeler c
362− , fromIdentity' @exprs4 $ hunlabel unlabeler d
363− , fromIdentity' @exprs5 $ hunlabel unlabeler e
364− )
365− toIdentity (a, b, c, d, e) = HQuintet
366− { hfst = hlabel labeler $ toIdentity' @exprs1 a
367− , hsnd = hlabel labeler $ toIdentity' @exprs2 b
368− , htrd = hlabel labeler $ toIdentity' @exprs3 c
369− , hfrt = hlabel labeler $ toIdentity' @exprs4 d
370− , hfft = hlabel labeler $ toIdentity' @exprs5 e
371− }
372−
373−
374−instance
375− ( HTable t
376− , isTabular ~ 'True
377− , result ~ Col Identity
378− , x ~ t (Col Expr)
379− ) => ExprsFor 'False isTabular (t result) x
380− where
381− fromIdentity = id
382− toIdentity = id
383
92
384
93
385instance
94instance
386− ( Encodes (t Identity) (t Expr)
95+ ( ToExprs exprs1 a
387− , isTabular ~ 'True
96+ , ToExprs exprs2 b
388− , result ~ Identity
97+ , ToExprs exprs3 c
389− , x ~ t Expr
98+ , ToExprs exprs4 d
390− ) => ExprsFor 'False isTabular (t result) x
99+ , ToExprs exprs5 e
391− where
100+ , ToExprs exprs6 f
392− fromIdentity = fromColumns
101+ , x ~ (exprs1, exprs2, exprs3, exprs4, exprs5, exprs6)
393− toIdentity = toColumns
102+ )
103+ => ToExprs x (a, b, c, d, e, f)
394
104
395
105
396instance
106instance
397− ( KnownSpec spec
107+ ( ToExprs exprs1 a
398− , isTabular ~ 'True
108+ , ToExprs exprs2 b
399− , isSpecial ~ 'True
109+ , ToExprs exprs3 c
400− , x ~ Col Expr spec
110+ , ToExprs exprs4 d
401− ) => ExprsFor 'False isTabular (Col' isSpecial Identity spec) x
111+ , ToExprs exprs5 e
402− where
112+ , ToExprs exprs6 f
403− fromIdentity = fromColumns
113+ , ToExprs exprs7 g
404− toIdentity = toColumns
114+ , x ~ (exprs1, exprs2, exprs3, exprs4, exprs5, exprs6, exprs7)
405−
115+ )
406−
116+ => ToExprs x (a, b, c, d, e, f, g)
407−type FromExprs :: Type -> Type
408−type family FromExprs a where
409− FromExprs (Expr a) = a
410− FromExprs (Col' _ Expr spec) = Col Identity spec
411− FromExprs (EitherTable a b) = Either (FromExprs a) (FromExprs b)
412− FromExprs (ListTable a) = [FromExprs a]
413− FromExprs (MaybeTable a) = Maybe (FromExprs a)
414− FromExprs (NonEmptyTable a) = NonEmpty (FromExprs a)
415− FromExprs (TheseTable a b) = These (FromExprs a) (FromExprs b)
416− FromExprs (a, b) = (FromExprs a, FromExprs b)
417− FromExprs (a, b, c) = (FromExprs a, FromExprs b, FromExprs c)
418− FromExprs (a, b, c, d) =
419− (FromExprs a, FromExprs b, FromExprs c, FromExprs d)
420− FromExprs (a, b, c, d, e) =
421− (FromExprs a, FromExprs b, FromExprs c, FromExprs d, FromExprs e)
422− FromExprs (t Expr) = t Identity
423− FromExprs (t (Col' _ Expr)) = t (Col Identity)
424
117
425
118
426-- | @Serializable@ witnesses the one-to-one correspondence between the type
119-- | @Serializable@ witnesses the one-to-one correspondence between the type
427-- @sql@, which contains SQL expressions, and the type @haskell@, which
120-- @sql@, which contains SQL expressions, and the type @haskell@, which
428-- contains the Haskell decoding of rows containing @sql@ SQL expressions.
121-- contains the Haskell decoding of rows containing @sql@ SQL expressions.
122+type Serializable :: Type -> Type -> Constraint
429−class (ToExprs a exprs, a ~ FromExprs exprs) => Serializable exprs a | exprs -> a
123+class (ToExprs exprs a, a ~ FromExprs exprs) => Serializable exprs a | exprs -> a
430−instance (ToExprs a exprs, a ~ FromExprs exprs) => Serializable exprs a
124+instance (ToExprs exprs a, a ~ FromExprs exprs) => Serializable exprs a
431−instance Serializable (Expr Opaque) Opaque
125+instance {-# OVERLAPPING #-} Sql DBType a => Serializable (Expr a) a
432
126
433
127
128+-- | Use @lit@ to turn literal Haskell values into expressions. @lit@ is
129+-- capable of lifting single @Expr@s to full tables.
434lit :: forall exprs a. Serializable exprs a => a -> exprs
130lit :: forall exprs a. Serializable exprs a => a -> exprs
435−lit = fromColumns . litTable . toIdentity' @exprs
131+lit = fromColumns . litHTable . toResult @_ @exprs
436
132
437
133
438parse :: forall exprs a. Serializable exprs a => Hasql.Row a
134parse :: forall exprs a. Serializable exprs a => Hasql.Row a
439−parse = fromIdentity' @exprs <$> parseTable
135+parse = fromResult @_ @exprs <$> parseHTable
440
136
441
137
442−litTable :: Encodes a b => a -> b
138+litHTable :: HTable t => t Result -> t Expr
443−litTable (toColumns -> as) = fromColumns $ htabulate $ \field ->
139+litHTable as = htabulate $ \field ->
444 case hfield hspecs field of
140 case hfield hspecs field of
445− SSpec {nullability, info} -> case hfield as field of
141+ Spec {nullity, info} -> case hfield as field of
446− Result value -> DB (slitExpr nullability info value)
142+ Identity value -> slitExpr nullity info value
447
143
448
144
449−parseTable :: Table Identity a => Hasql.Row a
145+parseHTable :: HTable t => Hasql.Row (t Result)
450−parseTable = fmap fromColumns $ unwrapApplicative $ htabulateA $ \field ->
146+parseHTable = unwrapApplicative $ htabulateA $ \field ->
451 WrapApplicative $ case hfield hspecs field of
147 WrapApplicative $ case hfield hspecs field of
452− SSpec {nullability, info} -> Result <$> sparseValue nullability info
148+ Spec {nullity, info} -> Identity <$> sparseValue nullity info
src/Rel8/Table/These.hs+233−108
@@ -5,84 +5,122 @@
5{-# language FlexibleInstances #-}
5{-# language FlexibleInstances #-}
6{-# language MultiParamTypeClasses #-}
6{-# language MultiParamTypeClasses #-}
7{-# language NamedFieldPuns #-}
7{-# language NamedFieldPuns #-}
8+{-# language ScopedTypeVariables #-}
8{-# language StandaloneKindSignatures #-}
9{-# language StandaloneKindSignatures #-}
9{-# language TupleSections #-}
10{-# language TupleSections #-}
11+{-# language TypeApplications #-}
10{-# language TypeFamilies #-}
12{-# language TypeFamilies #-}
11{-# language UndecidableInstances #-}
13{-# language UndecidableInstances #-}
12
14
15+{-# options_ghc -fno-warn-orphans #-}
16+
13module Rel8.Table.These
17module Rel8.Table.These
14 ( TheseTable(..)
18 ( TheseTable(..)
15 , theseTable, thisTable, thatTable, thoseTable
19 , theseTable, thisTable, thatTable, thoseTable
16 , isThisTable, isThatTable, isThoseTable
20 , isThisTable, isThatTable, isThoseTable
17 , hasHereTable, hasThereTable
21 , hasHereTable, hasThereTable
18 , justHereTable, justThereTable
22 , justHereTable, justThereTable
23+ , alignMaybeTable
24+ , aggregateTheseTable
25+ , nameTheseTable
19 )
26 )
20where
27where
21
28
22-- base
29-- base
23import Data.Bifunctor ( Bifunctor, bimap )
30import Data.Bifunctor ( Bifunctor, bimap )
24−import Data.Functor.Identity ( runIdentity )
25import Data.Kind ( Type )
31import Data.Kind ( Type )
32+import Data.Maybe ( isJust )
26−import Prelude hiding ( undefined )
33+import Prelude hiding ( null, undefined )
27
34
28-- rel8
35-- rel8
36+import Rel8.Aggregate ( Aggregate )
29import Rel8.Expr ( Expr )
37import Rel8.Expr ( Expr )
30−import Rel8.Expr.Bool ( (&&.), not_ )
38+import Rel8.Expr.Bool ( (&&.), (||.), boolExpr, not_ )
31−import Rel8.Expr.Null ( isNonNull )
39+import Rel8.Expr.Null ( null, isNonNull )
32−import Rel8.Schema.Context.Label ( Labelable, labeler, unlabeler )
40+import Rel8.Kind.Context ( Reifiable )
33−import Rel8.Schema.Context.Nullify
41+import Rel8.Schema.Context.Nullify ( Nullifiable )
34− ( Nullifiable, NullifiableEq
42+import Rel8.Schema.Dict ( Dict( Dict ) )
35− , encodeTag, decodeTag
36− , nullifier, unnullifier
37− )
38−import Rel8.Schema.HTable.Label ( HLabel, hlabel, hunlabel )
43+import Rel8.Schema.HTable.Label ( hlabel, hrelabel, hunlabel )
39import Rel8.Schema.HTable.Identity ( HIdentity(..) )
44import Rel8.Schema.HTable.Identity ( HIdentity(..) )
40−import Rel8.Schema.HTable.Nullify ( hnullify, hunnullify )
45+import Rel8.Schema.HTable.Maybe ( HMaybeTable(..) )
41import Rel8.Schema.HTable.These ( HTheseTable(..) )
46import Rel8.Schema.HTable.These ( HTheseTable(..) )
47+import qualified Rel8.Schema.Kind as K
48+import Rel8.Schema.Name ( Name )
49+import Rel8.Table
42−import Rel8.Table ( Table, Columns, Context, fromColumns, toColumns )
50+ ( Table, Columns, Context, fromColumns, toColumns
43−import Rel8.Table.Lifted
51+ , FromExprs, fromResult, toResult
44− ( Table1, Columns1, ConstrainContext1, fromColumns1, toColumns1
52+ , Transpose
45− , Table2, Columns2, ConstrainContext2, fromColumns2, toColumns2
46 )
53 )
54+import Rel8.Table.Eq ( EqTable, eqTable )
47import Rel8.Table.Maybe
55import Rel8.Table.Maybe
48 ( MaybeTable(..)
56 ( MaybeTable(..)
49 , maybeTable, justTable, nothingTable
57 , maybeTable, justTable, nothingTable
50 , isJustTable
58 , isJustTable
59+ , aggregateMaybeTable
60+ , nameMaybeTable
51 )
61 )
52−import Rel8.Table.Recontextualize ( Recontextualize )
62+import Rel8.Table.Nullify ( Nullify, guard )
63+import Rel8.Table.Ord ( OrdTable, ordTable )
64+import Rel8.Table.Projection ( Biprojectable, Projectable, biproject, project )
65+import Rel8.Table.Serialize ( ToExprs )
53import Rel8.Table.Undefined ( undefined )
66import Rel8.Table.Undefined ( undefined )
67+import Rel8.Type.Tag ( MaybeTag )
54
68
55-- semigroupoids
69-- semigroupoids
56import Data.Functor.Apply ( Apply, (<.>) )
70import Data.Functor.Apply ( Apply, (<.>) )
57import Data.Functor.Bind ( Bind, (>>-) )
71import Data.Functor.Bind ( Bind, (>>-) )
58
72
59−
73+-- these
74+import Data.These ( These( This, That, These ) )
75+import Data.These.Combinators ( justHere, justThere )
76+
77+
78+-- | @TheseTable a b@ is a Rel8 table that contains either the table @a@, the
79+-- table @b@, or both tables @a@ and @b@. You can construct @TheseTable@s using
80+-- 'thisTable', 'thatTable' and 'thoseTable'. @TheseTable@s can be
81+-- eliminated/pattern matched using 'theseTable'.
82+--
83+-- @TheseTable@ is operationally the same as Haskell's 'These' type, but
84+-- adapted to work with Rel8.
60−type TheseTable :: Type -> Type -> Type
85+type TheseTable :: K.Context -> Type -> Type -> Type
61−data TheseTable a b = TheseTable
86+data TheseTable context a b = TheseTable
62− { here :: MaybeTable a
87+ { here :: MaybeTable context a
63− , there :: MaybeTable b
88+ , there :: MaybeTable context b
64 }
89 }
65− deriving stock (Show, Functor)
90+ deriving stock Functor
91+
92+
93+instance Biprojectable (TheseTable context) where
94+ biproject f g (TheseTable a b) = TheseTable (project f a) (project g b)
66
95
67
96
68−instance Bifunctor TheseTable where
97+instance Nullifiable context => Bifunctor (TheseTable context) where
69 bimap f g (TheseTable a b) = TheseTable (fmap f a) (fmap g b)
98 bimap f g (TheseTable a b) = TheseTable (fmap f a) (fmap g b)
70
99
71
100
101+instance Projectable (TheseTable context a) where
102+ project f (TheseTable a b) = TheseTable a (project f b)
103+
104+
72−instance (Table Expr a, Semigroup a) => Apply (TheseTable a) where
105+instance (context ~ Expr, Table Expr a, Semigroup a) =>
106+ Apply (TheseTable context a)
107+ where
73 fs <.> as = TheseTable
108 fs <.> as = TheseTable
74 { here = here fs <> here as
109 { here = here fs <> here as
75 , there = there fs <.> there as
110 , there = there fs <.> there as
76 }
111 }
77
112
78
113
79−instance (Table Expr a, Semigroup a) => Applicative (TheseTable a)
114+instance (context ~ Expr, Table Expr a, Semigroup a) =>
115+ Applicative (TheseTable context a)
80 where
116 where
81 pure = thatTable
117 pure = thatTable
82 (<*>) = (<.>)
118 (<*>) = (<.>)
83
119
84
120
85−instance (Table Expr a, Semigroup a) => Bind (TheseTable a) where
121+instance (context ~ Expr, Table Expr a, Semigroup a) =>
122+ Bind (TheseTable context a)
123+ where
86 TheseTable here1 ma >>- f = case ma >>- f' of
124 TheseTable here1 ma >>- f = case ma >>- f' of
87 mtb -> TheseTable
125 mtb -> TheseTable
88 { here = maybeTable here1 ((here1 <>) . fst) mtb
126 { here = maybeTable here1 ((here1 <>) . fst) mtb
@@ -93,12 +131,14 @@ instance (Table Expr a, Semigroup a) => Bind (TheseTable a) where
93 TheseTable here2 mb -> (here2,) <$> mb
131 TheseTable here2 mb -> (here2,) <$> mb
94
132
95
133
96−instance (Table Expr a, Semigroup a) => Monad (TheseTable a) where
134+instance (context ~ Expr, Table Expr a, Semigroup a) =>
135+ Monad (TheseTable context a)
136+ where
97 (>>=) = (>>-)
137 (>>=) = (>>-)
98
138
99
139
100−instance (Table Expr a, Table Expr b, Semigroup a, Semigroup b) =>
140+instance (context ~ Expr, Table Expr a, Table Expr b, Semigroup a, Semigroup b) =>
101− Semigroup (TheseTable a b)
141+ Semigroup (TheseTable context a b)
102 where
142 where
103 a <> b = TheseTable
143 a <> b = TheseTable
104 { here = here a <> here b
144 { here = here a <> here b
@@ -106,127 +146,212 @@ instance (Table Expr a, Table Expr b, Semigroup a, Semigroup b) =>
106 }
146 }
107
147
108
148
109−instance Table2 TheseTable where
149+instance
150+ ( Table context a, Table context b
151+ , Reifiable context, context ~ context'
152+ )
153+ => Table context' (TheseTable context a b)
154+ where
110− type Columns2 TheseTable = HTheseTable
155+ type Columns (TheseTable context a b) = HTheseTable (Columns a) (Columns b)
111− type ConstrainContext2 TheseTable = Nullifiable
156+ type Context (TheseTable context a b) = Context a
112−
157+ type FromExprs (TheseTable context a b) =
158+ These (FromExprs a) (FromExprs b)
159+ type Transpose to (TheseTable context a b) =
160+ TheseTable to (Transpose to a) (Transpose to b)
161+
113− toColumns2 f g TheseTable {here, there} = HTheseTable
162+ toColumns TheseTable {here, there} = HTheseTable
114− { hhereTag = HIdentity $ encodeTag (tag here)
163+ { hhereTag = hlabel $ HIdentity $ tag here
115− , hhere = hnullify (nullifier (isNonNull (tag here))) $ f (just here)
164+ , hhere =
165+ hlabel $ guard (tag here) isJust isNonNull $ toColumns $ just here
116− , hthereTag = HIdentity $ encodeTag (tag there)
166+ , hthereTag = hlabel $ HIdentity $ tag there
117− , hthere = hnullify (nullifier (isNonNull (tag there))) $ g (just there)
167+ , hthere =
168+ hlabel $ guard (tag there) isJust isNonNull $ toColumns $ just there
118 }
169 }
119
170
120− fromColumns2 f g HTheseTable {hhereTag, hhere, hthereTag, hthere} =
171+ fromColumns HTheseTable {hhereTag, hhere, hthereTag, hthere} = TheseTable
121− TheseTable
122− { here =
172+ { here = MaybeTable
123− let
173+ { tag = unHIdentity $ hunlabel hhereTag
124− tag = decodeTag $ unHIdentity hhereTag
174+ , just = fromColumns $ hunlabel hhere
125− in
126− MaybeTable
127− { tag
128− , just = f $
129− runIdentity $
130− hunnullify (\a -> pure . unnullifier (isNonNull tag) a)
131− hhere
132− }
175+ }
133− , there =
176+ , there = MaybeTable
134− let
177+ { tag = unHIdentity $ hunlabel hthereTag
135− tag = decodeTag $ unHIdentity hthereTag
178+ , just = fromColumns $ hunlabel hthere
136− in
179+ }
137− MaybeTable
180+ }
138− { tag
139− , just = g $
140− runIdentity $
141− hunnullify (\a -> pure . unnullifier (isNonNull tag) a)
142− hthere
143− }
144− }
145−
146− {-# INLINABLE fromColumns2 #-}
147− {-# INLINABLE toColumns2 #-}
148−
149−
150−instance Table context a => Table1 (TheseTable a) where
151− type Columns1 (TheseTable a) = HTheseTable (Columns a)
152− type ConstrainContext1 (TheseTable a) = NullifiableEq (Context a)
153
181
154− toColumns1 = toColumns2 toColumns
182+ toResult tables = HTheseTable
155− fromColumns1 = fromColumns2 fromColumns
183+ { hhereTag = hrelabel hhereTag
184+ , hhere = hrelabel hhere
185+ , hthereTag = hrelabel hthereTag
186+ , hthere = hrelabel hthere
187+ }
188+ where
189+ HMaybeTable
190+ { htag = hhereTag
191+ , hjust = hhere
192+ } = toResult @_ @(MaybeTable context a) (justHere tables)
193+ HMaybeTable
194+ { htag = hthereTag
195+ , hjust = hthere
196+ } = toResult @_ @(MaybeTable context b) (justThere tables)
197+
198+ fromResult HTheseTable {hhereTag, hhere, hthereTag, hthere} =
199+ case (here, there) of
200+ (Just a, Nothing) -> This a
201+ (Nothing, Just b) -> That b
202+ (Just a, Just b) -> These a b
203+ _ -> error "These.fromColumns: mismatch between tags and data"
204+ where
205+ here = fromResult @_ @(MaybeTable context a) mhere
206+ there = fromResult @_ @(MaybeTable context b) mthere
207+ mhere = HMaybeTable
208+ { htag = hrelabel hhereTag
209+ , hjust = hrelabel hhere
210+ }
211+ mthere = HMaybeTable
212+ { htag = hrelabel hthereTag
213+ , hjust = hrelabel hthere
214+ }
215+
216+
217+instance (EqTable a, EqTable b, context ~ Expr) =>
218+ EqTable (TheseTable context a b)
219+ where
220+ eqTable = HTheseTable
221+ { hhereTag = hlabel (HIdentity Dict)
222+ , hhere = hlabel (eqTable @(Nullify context a))
223+ , hthereTag = hlabel (HIdentity Dict)
224+ , hthere = hlabel (eqTable @(Nullify context b))
225+ }
156
226
157
227
158−instance
228+instance (OrdTable a, OrdTable b, context ~ Expr) =>
159− ( Table context a, Table context b
160− , Labelable context, Nullifiable context
161− ) => Table context (TheseTable a b)
229+ OrdTable (TheseTable context a b)
162 where
230 where
163− type Columns (TheseTable a b) =
231+ ordTable = HTheseTable
164− HTheseTable (HLabel "Here" (Columns a)) (HLabel "There" (Columns b))
232+ { hhereTag = hlabel (HIdentity Dict)
165− type Context (TheseTable a b) = Context a
233+ , hhere = hlabel (ordTable @(Nullify context a))
234+ , hthereTag = hlabel (HIdentity Dict)
235+ , hthere = hlabel (ordTable @(Nullify context b))
236+ }
166
237
167− toColumns =
168− toColumns2
169− (hlabel labeler . toColumns)
170− (hlabel labeler . toColumns)
171− fromColumns =
172− fromColumns2
173− (fromColumns . hunlabel unlabeler)
174− (fromColumns . hunlabel unlabeler)
175
238
239+instance (ToExprs exprs1 a, ToExprs exprs2 b, x ~ TheseTable Expr exprs1 exprs2) =>
240+ ToExprs x (These a b)
176
241
177−instance
178− ( Labelable from, Nullifiable from
179− , Labelable to, Nullifiable to
180− , Recontextualize from to a1 b1
181− , Recontextualize from to a2 b2
182− ) =>
183− Recontextualize from to (TheseTable a1 a2) (TheseTable b1 b2)
184
242
185−
243+-- | Test if a 'TheseTable' was constructed with 'thisTable'.
244+--
245+-- Corresponds to 'Data.These.Combinators.isThis'.
186−isThisTable :: TheseTable a b -> Expr Bool
246+isThisTable :: TheseTable Expr a b -> Expr Bool
187isThisTable a = hasHereTable a &&. not_ (hasThereTable a)
247isThisTable a = hasHereTable a &&. not_ (hasThereTable a)
188
248
189
249
250+-- | Test if a 'TheseTable' was constructed with 'thatTable'.
251+--
252+-- Corresponds to 'Data.These.Combinators.isThat'.
190−isThatTable :: TheseTable a b -> Expr Bool
253+isThatTable :: TheseTable Expr a b -> Expr Bool
191isThatTable a = not_ (hasHereTable a) &&. hasThereTable a
254isThatTable a = not_ (hasHereTable a) &&. hasThereTable a
192
255
193
256
257+-- | Test if a 'TheseTable' was constructed with 'thoseTable'.
258+--
259+-- Corresponds to 'Data.These.Combinators.isThese'.
194−isThoseTable :: TheseTable a b -> Expr Bool
260+isThoseTable :: TheseTable Expr a b -> Expr Bool
195isThoseTable a = hasHereTable a &&. hasThereTable a
261isThoseTable a = hasHereTable a &&. hasThereTable a
196
262
197
263
264+-- | Test if the @a@ side of @TheseTable a b@ is present.
265+--
266+-- Corresponds to 'Data.These.Combinators.hasHere'.
198−hasHereTable :: TheseTable a b -> Expr Bool
267+hasHereTable :: TheseTable Expr a b -> Expr Bool
199hasHereTable TheseTable {here} = isJustTable here
268hasHereTable TheseTable {here} = isJustTable here
200
269
201
270
271+-- | Test if the @b@ table of @TheseTable a b@ is present.
272+--
273+-- Corresponds to 'Data.These.Combinators.hasThere'.
202−hasThereTable :: TheseTable a b -> Expr Bool
274+hasThereTable :: TheseTable Expr a b -> Expr Bool
203hasThereTable TheseTable {there} = isJustTable there
275hasThereTable TheseTable {there} = isJustTable there
204
276
205
277
278+-- | Attempt to project out the @a@ table of a @TheseTable a b@.
279+--
280+-- Corresponds to 'Data.These.Combinators.justHere'.
206−justHereTable :: TheseTable a b -> MaybeTable a
281+justHereTable :: TheseTable context a b -> MaybeTable context a
207justHereTable = here
282justHereTable = here
208
283
209
284
285+-- | Attempt to project out the @b@ table of a @TheseTable a b@.
286+--
287+-- Corresponds to 'Data.These.Combinators.justThere'.
210−justThereTable :: TheseTable a b -> MaybeTable b
288+justThereTable :: TheseTable context a b -> MaybeTable context b
211justThereTable = there
289justThereTable = there
212
290
213
291
292+-- | Construct a @TheseTable@ from two 'MaybeTable's.
293+alignMaybeTable :: ()
294+ => MaybeTable Expr a
295+ -> MaybeTable Expr b
296+ -> MaybeTable Expr (TheseTable Expr a b)
297+alignMaybeTable a b = MaybeTable tag (pure (TheseTable a b))
298+ where
299+ tag = boolExpr null mempty (isJustTable a ||. isJustTable b)
300+
301+
302+-- | Construct a @TheseTable@. Corresponds to 'This'.
214−thisTable :: Table Expr b => a -> TheseTable a b
303+thisTable :: Table Expr b => a -> TheseTable Expr a b
215thisTable a = TheseTable (justTable a) nothingTable
304thisTable a = TheseTable (justTable a) nothingTable
216
305
217
306
307+-- | Construct a @TheseTable@. Corresponds to 'That'.
218−thatTable :: Table Expr a => b -> TheseTable a b
308+thatTable :: Table Expr a => b -> TheseTable Expr a b
219thatTable b = TheseTable nothingTable (justTable b)
309thatTable b = TheseTable nothingTable (justTable b)
220
310
221
311
312+-- | Construct a @TheseTable@. Corresponds to 'These'.
222−thoseTable :: a -> b -> TheseTable a b
313+thoseTable :: a -> b -> TheseTable Expr a b
223thoseTable a b = TheseTable (justTable a) (justTable b)
314thoseTable a b = TheseTable (justTable a) (justTable b)
224
315
225
316
317+-- | Pattern match on a 'TheseTable'. Corresponds to 'these'.
226theseTable :: Table Expr c
318theseTable :: Table Expr c
227− => (a -> c) -> (b -> c) -> (a -> b -> c) -> TheseTable a b -> c
319+ => (a -> c) -> (b -> c) -> (a -> b -> c) -> TheseTable Expr a b -> c
228theseTable f g h TheseTable {here, there} =
320theseTable f g h TheseTable {here, there} =
229 maybeTable
321 maybeTable
230 (maybeTable undefined f here)
322 (maybeTable undefined f here)
231 (\b -> maybeTable (g b) (`h` b) here)
323 (\b -> maybeTable (g b) (`h` b) here)
232 there
324 there
325+
326+
327+-- | Lift a pair of aggregating functions to operate on an 'TheseTable'.
328+-- @thisTable@s, @thatTable@s and @thoseTable@s are grouped separately.
329+aggregateTheseTable :: ()
330+ => (exprs -> aggregates)
331+ -> (exprs' -> aggregates')
332+ -> TheseTable Expr exprs exprs'
333+ -> TheseTable Aggregate aggregates aggregates'
334+aggregateTheseTable f g (TheseTable here there) = TheseTable
335+ { here = aggregateMaybeTable f here
336+ , there = aggregateMaybeTable g there
337+ }
338+
339+
340+-- | Construct a 'TheseTable' in the 'Name' context. This can be useful if you
341+-- have a 'TheseTable' that you are storing in a table and need to construct a
342+-- 'TableSchema'.
343+nameTheseTable :: ()
344+ => Name (Maybe MaybeTag)
345+ -- ^ The name of the column to track the presence of the @a@ table.
346+ -> Name (Maybe MaybeTag)
347+ -- ^ The name of the column to track the presence of the @b@ table.
348+ -> a
349+ -- ^ Names of the columns in the @a@ table.
350+ -> b
351+ -- ^ Names of the columns in the @b@ table.
352+ -> TheseTable Name a b
353+nameTheseTable here there a b =
354+ TheseTable
355+ { here = nameMaybeTable here a
356+ , there = nameMaybeTable there b
357+ }
src/Rel8/Table/Transpose.hsnew file+46
@@ -0,0 +1,46 @@
1+{-# language DataKinds #-}
2+{-# language FlexibleInstances #-}
3+{-# language FunctionalDependencies #-}
4+{-# language StandaloneKindSignatures #-}
5+{-# language TypeFamilies #-}
6+{-# language UndecidableInstances #-}
7+
8+module Rel8.Table.Transpose
9+ ( Transposes
10+ )
11+where
12+
13+-- base
14+import Data.Kind ( Constraint, Type )
15+import Prelude ()
16+
17+-- rel8
18+import qualified Rel8.Schema.Kind as K
19+import Rel8.Table ( Table, Transpose, Congruent )
20+
21+
22+-- | @'Transposes' from to a b@ means that @a@ and @b@ are 'Table's, in the
23+-- @from@ and @to@ contexts respectively, which share the same underlying
24+-- structure. In other words, @b@ is a version of @a@ transposed from the
25+-- @from@ context to the @to@ context (and vice versa).
26+type Transposes :: K.Context -> K.Context -> Type -> Type -> Constraint
27+class
28+ ( Table from a
29+ , Table to b
30+ , Congruent a b
31+ , b ~ Transpose to a
32+ , a ~ Transpose from b
33+ )
34+ => Transposes from to a b
35+ | a -> from
36+ , b -> to
37+ , a to -> b
38+ , b from -> a
39+instance
40+ ( Table from a
41+ , Table to b
42+ , Congruent a b
43+ , b ~ Transpose to a
44+ , a ~ Transpose from b
45+ )
46+ => Transposes from to a b
src/Rel8/Table/Undefined.hs+5−6
@@ -13,15 +13,14 @@ import Prelude hiding ( undefined )
13-- rel8
13-- rel8
14import Rel8.Expr ( Expr )
14import Rel8.Expr ( Expr )
15import Rel8.Expr.Null ( snull, unsafeUnnullify )
15import Rel8.Expr.Null ( snull, unsafeUnnullify )
16−import Rel8.Schema.Context ( Col'(..) )
17import Rel8.Schema.HTable ( htabulate, hfield, hspecs )
16import Rel8.Schema.HTable ( htabulate, hfield, hspecs )
18−import Rel8.Schema.Nullability ( Nullability( Nullable, NonNullable ) )
17+import Rel8.Schema.Null ( Nullity( Null, NotNull ) )
19−import Rel8.Schema.Spec ( SSpec(..) )
18+import Rel8.Schema.Spec ( Spec(..) )
20import Rel8.Table ( Table, fromColumns )
19import Rel8.Table ( Table, fromColumns )
21
20
22
21
23undefined :: Table Expr a => a
22undefined :: Table Expr a => a
24undefined = fromColumns $ htabulate $ \field -> case hfield hspecs field of
23undefined = fromColumns $ htabulate $ \field -> case hfield hspecs field of
25− SSpec {nullability, info} -> case nullability of
24+ Spec {nullity, info} -> case nullity of
26− Nullable -> DB (snull Nullable info)
25+ Null -> snull info
27− NonNullable -> DB (unsafeUnnullify (snull Nullable info))
26+ NotNull -> unsafeUnnullify (snull info)
src/Rel8/Table/Window.hsnew file+43
@@ -0,0 +1,43 @@
1+{-# language MonoLocalBinds #-}
2+
3+module Rel8.Table.Window
4+ ( cumulative
5+ , cumulative_
6+ , currentRow
7+ )
8+where
9+
10+-- base
11+import Prelude
12+
13+-- opaleye
14+import qualified Opaleye.Window as Opaleye
15+
16+-- rel8
17+import Rel8.Aggregate ( Aggregates )
18+import qualified Rel8.Expr.Window as Expr
19+import Rel8.Schema.HTable ( hfield, htabulateA )
20+import Rel8.Table ( fromColumns, toColumns )
21+import Rel8.Window ( Window( Window ) )
22+
23+
24+-- | 'cumulative' allows the use of aggregation functions in 'Window'
25+-- expressions. In particular, @'cumulative' 'Rel8.sum'@
26+-- (when combined with 'Rel8.Window.orderPartitionBy') gives a running total,
27+-- also known as a \"cumulative sum\", hence the name @cumulative@.
28+cumulative :: Aggregates aggregates exprs => (a -> aggregates) -> Window a exprs
29+cumulative f =
30+ fmap fromColumns $
31+ htabulateA $ \field ->
32+ Expr.cumulative ((`hfield` field) . toColumns . f)
33+
34+
35+-- | A version of 'cumulative' for use with nullary aggregators like
36+-- 'Rel8.Expr.Aggregate.countStar'.
37+cumulative_ :: Aggregates aggregates exprs => aggregates -> Window a exprs
38+cumulative_ = cumulative . const
39+
40+
41+-- | Return every column of the current row of a window query.
42+currentRow :: Window a a
43+currentRow = Window $ Opaleye.over (Opaleye.noWindowFunction id) mempty mempty
src/Rel8/Tabulate.hs+549−140
@@ -1,231 +1,640 @@
1−{-# language DeriveFunctor #-}
2−{-# language DerivingStrategies #-}
3{-# language FlexibleContexts #-}
1{-# language FlexibleContexts #-}
2+{-# language MonoLocalBinds #-}
3+{-# language ScopedTypeVariables #-}
4+{-# language StandaloneKindSignatures #-}
5+{-# language TypeApplications #-}
4{-# language TupleSections #-}
6{-# language TupleSections #-}
7+{-# language UndecidableInstances #-}
8+
9+-- | "Rel8.Tabulate" provides an alternative API ('Tabulation') for writing
10+-- queries that complements the main "Rel8" API ('Query').
5
11
6module Rel8.Tabulate
12module Rel8.Tabulate
13+ (
7− ( Tabulation
14+ Tabulation
8− , runTabulation
15+
9− , tabulate
16+ -- * Interfacing with 'Query's
10− , tabulateA
11 , fromQuery
17 , fromQuery
18+ , toQuery
12 , liftQuery
19 , liftQuery
13− , prebind
20+ , through
14− , postbind
15− , indexed
16− , ifilter
17 , lookup
21 , lookup
22+
23+ -- * Aggregation and Ordering
24+ , aggregate
25+ , distinct
26+ , order
27+
28+ -- ** Magic 'Tabulation's
29+ -- $magic
30+ , count
31+ , optional
32+ , many
33+ , some
34+ , exists
35+ , present
36+ , absent
37+
38+ -- * Natural joins
18 , align
39 , align
19 , alignWith
40 , alignWith
20 , leftAlign
41 , leftAlign
21 , leftAlignWith
42 , leftAlignWith
43+ , rightAlign
44+ , rightAlignWith
22 , zip
45 , zip
23 , zipWith
46 , zipWith
24 , similarity
47 , similarity
25 , difference
48 , difference
26− , aggregateTabulation
27− , optionalTabulation
28 )
49 )
29where
50where
30
51
31-- base
52-- base
32−import Control.Applicative ( liftA2 )
53+import Control.Applicative ( (<|>), empty, liftA2 )
33−import Control.Monad ( join, liftM2 )
54+import Control.Monad ( liftM2 )
34−import Data.Bifunctor ( bimap, first )
55+import Data.Bifunctor ( Bifunctor, bimap, first, second )
35import Data.Foldable ( traverse_ )
56import Data.Foldable ( traverse_ )
57+import Data.Function ( on )
58+import Data.Functor.Contravariant ( Contravariant, (>$<), contramap )
59+import Data.Int ( Int64 )
60+import Data.Kind ( Type )
36−import Data.Maybe ( fromMaybe )
61+import Data.Maybe ( fromJust, fromMaybe )
37−import Prelude hiding ( filter, lookup, undefined, zip, zipWith )
62+import Prelude hiding ( lookup, zip, zipWith )
63+
64+-- bifunctors
65+import Data.Bifunctor.Clown ( Clown( Clown ), runClown )
66+
67+-- comonad
68+import Control.Comonad ( extract )
69+
70+-- opaleye
71+import qualified Opaleye.Aggregate as Opaleye
72+import qualified Opaleye.Order as Opaleye ( orderBy, distinctOnExplicit )
73+
74+-- profunctors
75+import Data.Profunctor ( dimap, lmap )
76+
77+-- product-profunctors
78+import Data.Profunctor.Product
79+ ( ProductProfunctor, (***!)
80+ , SumProfunctor, (+++!)
81+ )
82+import qualified Data.Profunctor.Product as PP
38
83
39-- rel8
84-- rel8
40−import Rel8.Aggregate ( Aggregate )
85+import Rel8.Aggregate ( Aggregates )
41import Rel8.Expr ( Expr )
86import Rel8.Expr ( Expr )
42−import Rel8.Expr.Bool ( not_, true )
87+import Rel8.Expr.Aggregate ( countStar )
88+import Rel8.Expr.Bool ( true )
89+import Rel8.Order ( Order( Order ) )
43import Rel8.Query ( Query )
90import Rel8.Query ( Query )
44−import Rel8.Query.Aggregate ( aggregate )
91+import qualified Rel8.Query.Exists as Q ( exists, present, absent )
45−import Rel8.Query.Exists ( withBy, withoutBy )
46−import Rel8.Query.Filter ( filter, where_ )
92+import Rel8.Query.Filter ( where_ )
47−import Rel8.Query.Maybe ( optional )
93+import Rel8.Query.List ( catNonEmptyTable )
94+import qualified Rel8.Query.Maybe as Q ( optional )
95+import Rel8.Query.Opaleye ( mapOpaleye, unsafePeekQuery )
96+import Rel8.Query.Rebind ( rebind )
48import Rel8.Query.These ( alignBy )
97import Rel8.Query.These ( alignBy )
49−import Rel8.Table ( Table )
98+import Rel8.Table ( Table, fromColumns, toColumns )
50−import Rel8.Table.Aggregate ( groupBy )
99+import Rel8.Table.Aggregate ( hgroupBy, listAgg, nonEmptyAgg )
100+import Rel8.Table.Alternative
101+ ( AltTable, (<|>:)
102+ , AlternativeTable, emptyTable
103+ )
104+import Rel8.Table.Cols ( fromCols, toCols )
51−import Rel8.Table.Eq ( EqTable, (==:) )
105+import Rel8.Table.Eq ( EqTable, (==:), eqTable )
106+import Rel8.Table.List ( ListTable( ListTable ) )
52−import Rel8.Table.Maybe ( MaybeTable )
107+import Rel8.Table.Maybe ( MaybeTable( MaybeTable ), maybeTable )
108+import Rel8.Table.NonEmpty ( NonEmptyTable( NonEmptyTable ) )
109+import Rel8.Table.Opaleye ( aggregator, unpackspec )
110+import Rel8.Table.Ord ( OrdTable )
111+import Rel8.Table.Order ( ascTable )
112+import Rel8.Table.Projection
113+ ( Biprojectable, biproject
114+ , Projectable, project
115+ , apply
116+ )
53−import Rel8.Table.These ( TheseTable, theseTable )
117+import Rel8.Table.These ( TheseTable( TheseTable ), theseTable )
54−import Rel8.Table.Undefined ( undefined )
55
118
56-- semigroupoids
119-- semigroupoids
57import Data.Functor.Apply ( Apply, liftF2 )
120import Data.Functor.Apply ( Apply, liftF2 )
58−import Data.Functor.Bind ( Bind )
121+import Data.Functor.Bind ( Bind, (>>-) )
59−import qualified Data.Functor.Bind
122+
60−import Data.Semigroup.Traversable.Class ( bitraverse1 )
123+
124+type Key :: Type -> Type
125+type Key = Maybe
126+
127+
128+cat :: Table Expr k => Key k -> Query k
129+cat = maybe emptyTable pure
130+
131+
132+key :: (ProductProfunctor p, SumProfunctor p)
133+ => p a b -> p (Key a) (Key b)
134+key a = dimap from to (PP.empty +++! a)
135+ where
136+ from = maybe (Left ()) Right
137+ to = either (const Nothing) Just
138+
139+
140+keyed :: (ProductProfunctor p, SumProfunctor p)
141+ => p k l -> p a b -> p (Key k, a) (Key l, b)
142+keyed k a = key k ***! a
143+
144+
145+type Predicate :: Type -> Type
146+newtype Predicate a = Predicate (Maybe (a -> Expr Bool))
147+
148+
149+instance Contravariant Predicate where
150+ contramap f (Predicate a) = Predicate (lmap f <$> a)
151+
152+
153+instance Semigroup (Predicate k) where
154+ Predicate ma <> Predicate mb = Predicate $ ma <|> mb
155+
156+
157+instance Monoid (Predicate k) where
158+ mempty = Predicate Nothing
159+
160+
161+match :: EqTable k => Key k -> Predicate k
162+match = Predicate . fmap (==:)
163+
164+
165+ensure :: Predicate k -> Key k -> Query ()
166+ensure (Predicate mp) = traverse_ (\k -> traverse_ (\p -> where_ (p k)) mp)
167+
168+
169+-- | A @'Tabulation' k a@ is like a @'Query' a@, except that each row also
170+-- has a key @k@ in addition to the value @a@. 'Tabulation's can be composed
171+-- monadically just like 'Query's, but the resulting join is more like a
172+-- @NATURAL JOIN@ (based on the common key column(s) @k@) than the
173+-- @CROSS JOIN@ given by 'Query'.
174+--
175+-- Another way to think of @'Tabulation' k a@ is as analogous to @Map k a@ in
176+-- the same way @'Query' a@ is analogous to @[a]@. However, there's nothing
177+-- stopping a 'Tabulation' from containing multiple rows with the same key, so
178+-- technically @Map k (NonEmpty a)@ is more accurate.
179+--
180+-- 'Tabulation's can be created from 'Query's with 'fromQuery' and 'liftQuery'
181+-- and converted back to 'Query's with 'lookup' and 'toQuery' (though note the
182+-- caveats that come with the latter).
183+type Tabulation :: Type -> Type -> Type
184+newtype Tabulation k a = Tabulation (Predicate k -> Query (Key k, a))
61
185
62
186
63−newtype Tabulation k a = Tabulation (k -> Query (Maybe k, a))
187+instance Biprojectable Tabulation where
64− deriving stock Functor
188+ biproject f g =
189+ bimap
190+ (fromColumns . apply f . toColumns)
191+ (fromColumns . apply g . toColumns)
65
192
66
193
194+instance Bifunctor Tabulation where
195+ bimap f g (Tabulation a) = Tabulation $ \p ->
196+ bimap (fmap f) g <$> a (f >$< p)
197+
198+
199+instance Functor (Tabulation k) where
200+ fmap = second
201+
202+
203+instance Projectable (Tabulation k) where
204+ project f = fmap (fromColumns . apply f . toColumns)
205+
206+
207+-- | If @'Tabulation' k a@ is @Map k (NonEmpty a)@, then @(<.>)@ is
208+-- @intersectionWith (liftA2 (<*>))@
67instance EqTable k => Apply (Tabulation k) where
209instance EqTable k => Apply (Tabulation k) where
68 liftF2 = liftA2
210 liftF2 = liftA2
69
211
70
212
213+-- | @pure = 'liftQuery' . pure@
71instance EqTable k => Applicative (Tabulation k) where
214instance EqTable k => Applicative (Tabulation k) where
72 pure = liftQuery . pure
215 pure = liftQuery . pure
73 liftA2 = liftM2
216 liftA2 = liftM2
74
217
75
218
76instance EqTable k => Bind (Tabulation k) where
219instance EqTable k => Bind (Tabulation k) where
77− join = join
220+ Tabulation as >>- f = Tabulation $ \p -> do
221+ (k, a) <- as p
222+ case f a of
223+ Tabulation bs -> do
224+ let p' = match k
225+ (k', b) <- bs (p' <> p)
226+ ensure p' k'
227+ pure (k' <|> k, b)
78
228
79
229
80instance EqTable k => Monad (Tabulation k) where
230instance EqTable k => Monad (Tabulation k) where
81− Tabulation as >>= f = Tabulation $ \i -> do
231+ (>>=) = (>>-)
82− (mk, a) <- as i
83− case mk of
84− Nothing -> case f a of
85− Tabulation bs -> bs i
86− Just k -> case f a of
87− Tabulation bs -> do
88− (mk', b) <- bs k
89− case mk' of
90− Nothing -> pure (mk, b)
91− Just k' -> do
92− where_ $ k ==: k'
93− pure (mk', b)
94−
95−
96−runTabulation :: EqTable k => Tabulation k a -> Query (k, a)
97−runTabulation (Tabulation f) = do
98− (mk, a) <- f i
99− case mk of
100− Nothing -> do
101− -- Opaleye tries to be too clever optimising "WHERE FALSE" and generates
102− -- invalid SQL, so we use "WHERE NOT TRUE" instead
103− where_ $ not_ true
104− pure (i, a)
105− Just k -> pure (k, a)
106− where
107− i = undefined
108
232
109
233
110−liftQuery :: Query a -> Tabulation k a
234+-- | If @'Tabulation' k a@ is @Map k (NonEmpty a)@, then @(<|>:)@ is
111−liftQuery query = Tabulation $ const $ fmap (Nothing,) query
235+-- @unionWith (<>)@.
236+instance EqTable k => AltTable (Tabulation k) where
237+ tas <|>: tbs = do
238+ eas <- peek tas
239+ ebs <- peek tbs
240+ case (eas, ebs) of
241+ (Left as, Left bs) -> liftQuery $ as <|>: bs
242+ (Right as, Right bs) -> fromQuery $ as <|>: bs
243+ _ -> catNonEmptyTable `through` ((<>) `on` some) tas tbs
112
244
113
245
114−tabulate :: (a -> k) -> a -> Tabulation k a
246+instance EqTable k => AlternativeTable (Tabulation k) where
115−tabulate key a = fromQuery $ pure (key a, a)
247+ emptyTable = Tabulation $ const $ fmap (empty,) emptyTable
116
248
117
249
118−tabulateA :: (a -> Query k) -> a -> Tabulation k a
250+-- | If @'Tabulation' k a@ is @Map k (NonEmpty a)@, then @(<>)@ is
119−tabulateA key a = fromQuery $ (,a) <$> key a
251+-- @unionWith (liftA2 (<>))@.
252+instance (EqTable k, Table Expr a, Semigroup a) => Semigroup (Tabulation k a)
253+ where
254+ (<>) = alignWith (theseTable id id (<>))
120
255
121
256
122−fromQuery :: Query (k, a) -> Tabulation k a
257+instance (EqTable k, Table Expr a, Semigroup a) => Monoid (Tabulation k a)
123−fromQuery = Tabulation . const . fmap (first Just)
258+ where
259+ mempty = emptyTable
124
260
125
261
262+-- | Any 'Query' of key-value pairs @(k, a)@ can be a @'Tabulation' k a@.
263+fromQuery :: Query (k, a) -> Tabulation k a
264+fromQuery = Tabulation . const . fmap (first pure)
265+
266+
267+-- | Convert a @'Tabulation' k a@ back into a 'Query' of key-value pairs.
268+--
269+-- Note that the result of a 'toQuery' is undefined (will always return zero
270+-- rows) on 'Tabulation's constructed with 'liftQuery' or 'pure'. So while
271+-- @toQuery . fromQuery@ is always @id@, @fromQuery . toQuery@ is not.
272+--
273+-- A safer, more predictable alternative to 'toQuery' is to use 'lookup' with
274+-- an explicit set of keys:
275+--
276+-- @
277+-- do
278+-- k <- keys
279+-- a <- lookup k tabulation
280+-- pure (k, a)
281+-- @
282+--
283+-- Having said that, in practice, most legitimate uses of 'Tabulation' will
284+-- have a well-defined 'toQuery'. It would be possible in theory to encode
285+-- the necessary invariants at the type level using an indexed monad, but we
286+-- would lose the ability to use @do@-notation, which is the main benefit
287+-- of having 'Tabulation' as a monad in the first place.
288+--
289+-- In particular, @'toQuery' t@ is well-defined for any 'Tabulation' @t@
290+-- defined as @t = fromQuery _@. @'toQuery' t@ is also well-defined for any
291+-- 'Tabulation' @t@ defined as @t = t' >>= _@ or @t = t' *> _@ where
292+-- @'toQuery' t'@ is well-defined. There are other valid permutations too.
293+-- Generally, anything that uses 'fromQuery' at some point, unless wrapped in
294+-- a top-level 'present' or 'absent', will have a well-defined 'toQuery'.
126−indexed :: Tabulation k a -> Tabulation k (k, a)
295+toQuery :: Table Expr k => Tabulation k a -> Query (k, a)
127−indexed (Tabulation query) = Tabulation $ \i ->
296+toQuery (Tabulation f) = do
128− (\(mk, a) -> (mk, (fromMaybe i mk, a))) <$> query i
297+ (mk, a) <- f mempty
298+ k <- cat mk
299+ pure (k, a)
300+
301+
302+-- | A @'Query' a@ can be treated as a @'Tabulation' k a@ where the given @a@
303+-- values exist at every possible key @k@.
304+liftQuery :: Query a -> Tabulation k a
305+liftQuery = Tabulation . const . fmap (empty,)
129
306
130
307
308+-- | Run a Kleisli arrow in the the 'Query' monad \"through\" a 'Tabulation'.
309+-- Useful for 'Rel8.filter'ing a 'Tabulation'.
310+--
311+-- @
312+-- 'Rel8.filter' ((>=. 30) . userAge) `'through'` usersById
313+-- @
131−ifilter :: (k -> a -> Expr Bool) -> Tabulation k a -> Tabulation k a
314+through :: (a -> Query b) -> Tabulation k a -> Tabulation k b
132−ifilter f tabulation = snd <$> do
315+through f (Tabulation as) = Tabulation $ \p -> do
133− filter (uncurry f) `postbind` indexed tabulation
316+ (k, a) <- as p
317+ b <- f a
318+ pure (k, b)
319+infixr 1 `through`
134
320
135
321
322+-- | @'lookup' k t@ returns the value(s) at the key @k@ in the tabulation @t@.
136−prebind :: (a -> Tabulation k b) -> Query a -> Tabulation k b
323+lookup :: EqTable k => k -> Tabulation k a -> Query a
137−prebind f as = Tabulation $ \k -> do
324+lookup k (Tabulation f) = do
138− a <- as
325+ (k', a) <- f p
139− case f a of
326+ ensure p k'
140− Tabulation query -> query k
327+ pure a
141−infixr 1 `prebind`
328+ where
329+ p = match (pure k)
142
330
143
331
332+-- | 'aggregate' aggregates the values within each key of a
333+-- 'Tabulation'. There is an implicit @GROUP BY@ on all the key columns.
334+aggregate :: forall k aggregates exprs.
335+ ( EqTable k
336+ , Aggregates aggregates exprs
337+ )
144−postbind :: (a -> Query b) -> Tabulation k a -> Tabulation k b
338+ => Tabulation k aggregates -> Tabulation k exprs
145−postbind f (Tabulation as) = Tabulation $ \i -> do
339+aggregate (Tabulation f) = Tabulation $
146− (k, a) <- as i
340+ mapOpaleye (Opaleye.aggregate (keyed haggregator aggregator)) .
147− case f a of
341+ fmap (first (fmap (hgroupBy (eqTable @k) . toColumns))) .
148− bs -> do
342+ f
149− b <- bs
343+ where
150− pure (k, b)
344+ haggregator = dimap fromColumns fromCols aggregator
151−infixr 1 `postbind`
152
345
153
346
347+-- | 'distinct' ensures a 'Tabulation' has at most one value for
348+-- each key, i.e., it drops duplicates. In general it keeps only the
349+-- \"first\" value it encounters for each key, but note that \"first\" is
350+-- undefined unless you first call 'order'.
154−lookup :: EqTable k => k -> Tabulation k a -> Query a
351+distinct :: EqTable k => Tabulation k a -> Tabulation k a
155−lookup key (Tabulation query) = do
352+distinct (Tabulation f) = Tabulation $
156− (mk, a) <- query key
353+ mapOpaleye (Opaleye.distinctOnExplicit (key unpackspec) fst) . f
157− traverse_ (where_ . (key ==:)) mk
158− pure a
159
354
160
355
356+-- | 'order' orders the /values/ of a 'Tabulation' within their
357+-- respective keys. This specifies a defined order for 'distinct'.
358+-- It also defines the order of the lists produced by 'many' and
359+-- 'some'.
360+order :: OrdTable k => Order a -> Tabulation k a -> Tabulation k a
361+order ordering (Tabulation f) =
362+ Tabulation $ mapOpaleye (Opaleye.orderBy ordering') . f
363+ where
364+ Order ordering' = runClown (keyed (Clown ascTable) (Clown ordering))
365+
366+
367+-- $magic
368+--
369+-- Some of the following combinators produce \"magic\" 'Tabulation's. Let's
370+-- use 'count' as an example to demonstrate this concept. Consider
371+-- the following:
372+--
373+-- @
374+-- count $ fromQuery $ values
375+-- [ (lit 'a', lit True)
376+-- , (lit 'a', lit False)
377+-- , (lit 'b', lit True)
378+-- ]
379+-- @
380+--
381+-- You might expect this to be equivalent to the following 'Tabulation':
382+--
383+-- @
384+-- fromQuery $ values
385+-- [ (lit 'a', 2)
386+-- , (lit 'b', 1)
387+-- ]
388+-- @
389+--
390+-- However, it isn't quite. While the resulting 'Tabulation' does effectively
391+-- contain the above entries, it also behaves as though it contained the value
392+-- @0@ at every other possible key.
393+--
394+-- This means you can do:
395+--
396+-- @
397+-- do
398+-- user <- usersById
399+-- orderCount <- count ordersByUserId
400+-- @
401+--
402+-- To see how many orders a user has (getting @0@ if they have no orders).
403+
404+
405+-- | 'count' returns a count of how many entries are in the given
406+-- 'Tabulation' at each key.
407+--
408+-- The resulting 'Tabulation' is \"magic\" in that the value @0@ exists at
409+-- every possible key that wasn't in the given 'Tabulation'.
410+count :: EqTable k => Tabulation k a -> Tabulation k (Expr Int64)
411+count =
412+ fmap (maybeTable 0 id) .
413+ optional .
414+ aggregate .
415+ fmap (const countStar)
416+
417+
418+-- | 'optional' produces a \"magic\" 'Tabulation' whereby each
419+-- entry in the given 'Tabulation' is wrapped in 'Rel8.justTable', and every
420+-- other possible key contains a single 'Rel8.nothingTable'.
421+--
422+-- This is used to implement 'leftAlignWith'.
423+optional :: Tabulation k a -> Tabulation k (MaybeTable Expr a)
424+optional (Tabulation f) = Tabulation $ \p -> case p of
425+ Predicate Nothing -> fmap pure <$> f p
426+ _ -> fmap (\m -> (empty, snd <$> m)) $ Q.optional $ do
427+ (k, a) <- f p
428+ ensure p k
429+ pure (k, a)
430+
431+
432+-- | 'many' aggregates each entry with a particular key into a
433+-- single entry with all of the values contained in a 'ListTable'.
434+--
435+-- 'order' can be used to give this 'ListTable' a defined order.
436+--
437+-- The resulting 'Tabulation' is \"magic\" in that the value
438+-- @'Rel8.listTable []'@ exists at every possible key that wasn't in the given
439+-- 'Tabulation'.
161−align :: (EqTable k, Table Expr a, Table Expr b)
440+many :: (EqTable k, Table Expr a)
441+ => Tabulation k a -> Tabulation k (ListTable Expr a)
442+many =
443+ fmap (maybeTable mempty (\(ListTable a) -> ListTable a)) .
444+ optional .
445+ aggregate .
446+ fmap (listAgg . toCols)
447+
448+
449+-- | 'some' aggregates each entry with a particular key into a
450+-- single entry with all of the values contained in a 'NonEmptyTable'.
451+--
452+-- 'order' can be used to give this 'NonEmptyTable' a defined order.
453+some :: (EqTable k, Table Expr a)
162− => Tabulation k a -> Tabulation k b -> Tabulation k (TheseTable a b)
454+ => Tabulation k a -> Tabulation k (NonEmptyTable Expr a)
455+some =
456+ fmap (\(NonEmptyTable a) -> NonEmptyTable a) .
457+ aggregate .
458+ fmap (nonEmptyAgg . toCols)
459+
460+
461+-- | 'exists' produces a \"magic\" 'Tabulation' which contains the
462+-- value 'Rel8.true' at each key in the given 'Tabulation', and the value
463+-- 'Rel8.false' at every other possible key.
464+exists :: Tabulation k a -> Tabulation k (Expr Bool)
465+exists (Tabulation f) = Tabulation $ \p -> case p of
466+ Predicate Nothing -> (true <$) <$> f p
467+ _ -> fmap (empty,) $ Q.exists $ do
468+ (k, _) <- f p
469+ ensure p k
470+
471+
472+-- | 'present' produces a 'Tabulation' where a single @()@ row
473+-- exists for every key that was present in the given 'Tabulation'.
474+--
475+-- This is used to implement 'similarity'.
476+present :: Tabulation k a -> Tabulation k ()
477+present (Tabulation f) = Tabulation $ \p -> do
478+ Q.present $ do
479+ (k, _) <- f p
480+ ensure p k
481+ pure (empty, ())
482+
483+
484+-- | 'absent' produces a 'Tabulation' where a single @()@ row exists
485+-- at every possible key that absent from the given 'Tabulation'.
486+--
487+-- This is used to implement 'difference'.
488+absent :: Tabulation k a -> Tabulation k ()
489+absent (Tabulation f) = Tabulation $ \p -> do
490+ Q.absent $ do
491+ (k, _) <- f p
492+ ensure p k
493+ pure (empty, ())
494+
495+
496+-- | Performs a @NATURAL FULL OUTER JOIN@ based on the common key columns.
497+--
498+-- Analogous to 'Data.Semialign.align'.
499+align :: EqTable k
500+ => Tabulation k a -> Tabulation k b -> Tabulation k (TheseTable Expr a b)
163align = alignWith id
501align = alignWith id
164
502
165
503
504+-- | Performs a @NATURAL FULL OUTER JOIN@ based on the common key columns.
505+--
506+-- Analogous to 'Data.Semialign.alignWith'.
166−alignWith :: (EqTable k, Table Expr a, Table Expr b)
507+alignWith :: EqTable k
167− => (TheseTable a b -> c)
508+ => (TheseTable Expr a b -> c)
168 -> Tabulation k a -> Tabulation k b -> Tabulation k c
509 -> Tabulation k a -> Tabulation k b -> Tabulation k c
169−alignWith f kas kbs = do
510+alignWith f (Tabulation as) (Tabulation bs) = Tabulation $ \p -> do
170− as <- toQuery kas
171− bs <- toQuery kbs
172− fromQuery $ do
173− tkab <- alignBy (\(l, _) (m, _) -> l ==: m) as bs
511+ tkab <- liftF2 (alignBy condition) as bs p
174− let
512+ k <- traverse (rebind "key") $ recover $ bimap fst fst tkab
175− k' = theseTable fst fst (const fst) tkab
513+ let
176− tab = bimap snd snd tkab
514+ tab = bimap snd snd tkab
177− pure (k', f tab)
515+ pure (k, f tab)
178−
516+ where
179−
517+ condition (k, _) (k', _) = fromMaybe true (liftA2 (==:) k k')
518+ recover (TheseTable mma@(MaybeTable _ ma) mmb@(MaybeTable _ mb)) =
519+ case extract ma of
520+ Nothing -> extract mb
521+ Just a -> case extract mb of
522+ Nothing -> extract ma
523+ Just b -> case a <$ mma <|>: b <$ mmb of
524+ MaybeTable _ c -> pure (extract c)
525+
526+
527+-- | Performs a @NATURAL LEFT OUTER JOIN@ based on the common key columns.
528+--
529+-- Analogous to 'Data.Semialign.rpadZip'.
530+--
531+-- Note that you can achieve the same effect with 'optional' and the
532+-- 'Applicative' instance for 'Tabulation', i.e., this is just
533+-- @\left right -> liftA2 (,) left (optional right). You can also
534+-- use @do@-notation.
180leftAlign :: EqTable k
535leftAlign :: EqTable k
181− => Tabulation k a -> Tabulation k b -> Tabulation k (a, MaybeTable b)
536+ => Tabulation k a -> Tabulation k b -> Tabulation k (a, MaybeTable Expr b)
182leftAlign = leftAlignWith (,)
537leftAlign = leftAlignWith (,)
183
538
184
539
540+-- | Performs a @NATURAL LEFT OUTER JOIN@ based on the common key columns.
541+--
542+-- Analogous to 'Data.Semialign.rpadZipWith'.
543+--
544+-- Note that you can achieve the same effect with 'optional' and the
545+-- 'Applicative' instance for 'Tabulation', i.e., this is just
546+-- @\f left right -> liftA2 f left (optional right). You can also
547+-- use @do@-notation.
185leftAlignWith :: EqTable k
548leftAlignWith :: EqTable k
186− => (a -> MaybeTable b -> c)
549+ => (a -> MaybeTable Expr b -> c)
187 -> Tabulation k a -> Tabulation k b -> Tabulation k c
550 -> Tabulation k a -> Tabulation k b -> Tabulation k c
188−leftAlignWith f left right = liftA2 f left (optionalTabulation right)
551+leftAlignWith f left right = liftA2 f left (optional right)
552+
553+
554+-- | Performs a @NATURAL RIGHT OUTER JOIN@ based on the common key columns.
555+--
556+-- Analogous to 'Data.Semialign.lpadZip'.
557+--
558+-- Note that you can achieve the same effect with 'optional' and the
559+-- 'Applicative' instance for 'Tabulation', i.e., this is just
560+-- @\left right -> liftA2 (flip (,)) right (optional left). You can
561+-- also use @do@-notation.
562+rightAlign :: EqTable k
563+ => Tabulation k a -> Tabulation k b -> Tabulation k (MaybeTable Expr a, b)
564+rightAlign = rightAlignWith (,)
565+
566+
567+-- | Performs a @NATURAL RIGHT OUTER JOIN@ based on the common key columns.
568+--
569+-- Analogous to 'Data.Semialign.lpadZipWith'.
570+--
571+-- Note that you can achieve the same effect with 'optional' and the
572+-- 'Applicative' instance for 'Tabulation', i.e., this is just
573+-- @\f left right -> liftA2 (flip f) right (optional left). You can
574+-- also use @do@-notation.
575+rightAlignWith :: EqTable k
576+ => (MaybeTable Expr a -> b -> c)
577+ -> Tabulation k a -> Tabulation k b -> Tabulation k c
578+rightAlignWith f left right = liftA2 (flip f) right (optional left)
189
579
190
580
581+-- | Performs a @NATURAL INNER JOIN@ based on the common key columns.
582+--
583+-- Analagous to 'Data.Semialign.zip'.
584+--
585+-- Note that you can achieve the same effect with the 'Applicative' instance
586+-- of 'Tabulation', i.e., this is just @'liftA2 (,)'@. You can also use
587+-- @do@-notation.
191zip :: EqTable k
588zip :: EqTable k
192 => Tabulation k a -> Tabulation k b -> Tabulation k (a, b)
589 => Tabulation k a -> Tabulation k b -> Tabulation k (a, b)
193zip = zipWith (,)
590zip = zipWith (,)
194
591
195
592
593+-- | Performs a @NATURAL INNER JOIN@ based on the common key columns.
594+--
595+-- Analagous to 'Data.Semialign.zipWith'.
596+--
597+-- Note that you can achieve the same effect with the 'Applicative' instance
598+-- of 'Tabulation', i.e., this is just @'liftA2'@. You can also use
599+-- @do@-notation.
196zipWith :: EqTable k
600zipWith :: EqTable k
197 => (a -> b -> c) -> Tabulation k a -> Tabulation k b -> Tabulation k c
601 => (a -> b -> c) -> Tabulation k a -> Tabulation k b -> Tabulation k c
198zipWith = liftA2
602zipWith = liftA2
199
603
200
604
605+-- | Performs a [@NATURAL SEMI JOIN@](https://en.wikipedia.org/wiki/Relational_algebra#Semijoin_%28%E2%8B%89%29%28%E2%8B%8A%29)
606+-- based on the common key columns.
607+--
608+-- The result is a subset of the left tabulation where only entries which have
609+-- a corresponding entry in the right tabulation are kept.
610+--
611+-- Note that you can achieve a similar effect with 'present' and the
612+-- 'Applicative' instance of 'Tabulation', i.e., this is just
613+-- @\left right -> left <* present right@. You can also use
614+-- @do@-notation.
201similarity :: EqTable k => Tabulation k a -> Tabulation k b -> Tabulation k a
615similarity :: EqTable k => Tabulation k a -> Tabulation k b -> Tabulation k a
202−similarity kas kbs = do
616+similarity a b = a <* present b
203− as <- toQuery kas
617+
204− bs <- toQuery kbs
618+
205− fromQuery $ as >>= withBy (\(k, _) (l, _) -> k ==: l) bs
619+-- | Performs a [@NATURAL ANTI JOIN@](https://en.wikipedia.org/wiki/Relational_algebra#Antijoin_%28%E2%96%B7%29)
206−
620+-- based on the common key columns.
207−
621+--
622+-- The result is a subset of the left tabulation where only entries which do
623+-- not have a corresponding entry in the right tabulation are kept.
624+--
625+-- Note that you can achieve a similar effect with 'absent' and the
626+-- 'Applicative' instance of 'Tabulation', i.e., this is just
627+-- @\left right -> left <* absent right@. You can also use
628+-- @do@-notation.
208difference :: EqTable k => Tabulation k a -> Tabulation k b -> Tabulation k a
629difference :: EqTable k => Tabulation k a -> Tabulation k b -> Tabulation k a
209−difference kas kbs = do
630+difference a b = a <* absent b
210− as <- toQuery kas
211− bs <- toQuery kbs
212− fromQuery $ as >>= withoutBy (\(k, _) (l, _) -> k ==: l) bs
213−
214−
215−aggregateTabulation :: EqTable k
216− => Tabulation k (Aggregate a) -> Tabulation k a
217−aggregateTabulation kas = do
218− as <- toQuery kas
219− fromQuery $ aggregate $ bitraverse1 groupBy id <$> as
220−
221−
222−optionalTabulation :: EqTable k
223− => Tabulation k a -> Tabulation k (MaybeTable a)
224−optionalTabulation as = Tabulation $ \k -> do
225− ma <- optional $ lookup k as
226− pure (Just k, ma)
227
631
228
632
633+-- | 'Tabulation's can be produced with either 'fromQuery' or 'liftQuery', and
634+-- in some cases we might want to treat these differently. 'peek' uses
635+-- 'unsafePeekQuery' to determine which type of 'Tabulation' we have.
229−toQuery :: Tabulation k a -> Tabulation k (Query (k, a))
636+peek :: Tabulation k a -> Tabulation k (Either (Query a) (Query (k, a)))
230−toQuery (Tabulation as) = Tabulation $ \k ->
637+peek (Tabulation f) = Tabulation $ \p ->
231− pure (Nothing, first (fromMaybe k) <$> as k)
638+ pure $ (empty,) $ case unsafePeekQuery (f p) of
639+ (Nothing, _) -> Left $ fmap snd (f p)
640+ (Just _, _) -> Right $ fmap (first fromJust) (f p)
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