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rel8/src/Rel8/Table/Rel8able.hs
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1{-# language DataKinds #-}
2{-# language FlexibleInstances #-}
3{-# language FunctionalDependencies #-}
4{-# language ScopedTypeVariables #-}
5{-# language StandaloneKindSignatures #-}
6{-# language TypeApplications #-}
7{-# language TypeFamilies #-}
8{-# language UndecidableInstances #-}
10{-# options_ghc -fno-warn-orphans #-}
12module Rel8.Table.Rel8able
13 (
14 )
15where
17-- base
18import Data.Kind ( Constraint, Type )
19import Data.Type.Equality ( (:~:)( Refl ) )
20import Prelude
22-- rel8
23import Rel8.Expr ( Expr )
24import qualified Rel8.Kind.Algebra as K
25import Rel8.Kind.Context
26 ( SContext( SReify )
27 , Reifiable, contextSing
28 , sReifiable
29 )
30import Rel8.Generic.Rel8able
31 ( Rel8able, Algebra
32 , GColumns, gfromColumns, gtoColumns
33 , greify, gunreify
34 )
35import Rel8.Schema.Context ( Col )
36import Rel8.Schema.Dict ( Dict( Dict ) )
37import qualified Rel8.Schema.Kind as K
38import Rel8.Schema.HTable ( HConstrainTable, hdicts )
39import Rel8.Schema.Reify ( hreify, hunreify, UnwrapReify )
40import Rel8.Schema.Result ( Result )
41import Rel8.Table
42 ( Table, Columns, Context, Congruent, fromColumns, toColumns
43 , Unreify, reify, unreify
44 )
45import Rel8.Schema.Spec.ConstrainDBType ( ConstrainDBType )
46import Rel8.Table.ADT ( ADT( ADT ), ADTable, fromADT, toADT )
47import Rel8.Table.Eq ( EqTable, eqTable )
48import Rel8.Table.HKD ( HKD )
49import Rel8.Table.Ord ( OrdTable, ordTable )
50import Rel8.Table.Recontextualize ( Recontextualize )
51import Rel8.Table.Serialize ( FromExprs, ToExprs, fromResult, toResult )
52import Rel8.Type.Eq ( DBEq )
53import Rel8.Type.Ord ( DBOrd )
56instance (Rel8able t, Reifiable context) =>
57 Table context (t context)
58 where
59 type Columns (t context) = GColumns t
60 type Context (t context) = context
61 type Unreify (t context) = t (UnwrapReify context)
63 fromColumns = gunreify . gfromColumns . hreify
64 toColumns = hunreify . gtoColumns . greify
66 reify Refl = case contextSing @context of
67 SReify context -> case sReifiable context of
68 Dict -> greify
70 unreify Refl = case contextSing @context of
71 SReify context -> case sReifiable context of
72 Dict -> gunreify
75instance
76 ( Rel8able t
77 , Reifiable from
78 , Reifiable to
79 , Congruent (t from) (t to)
80 )
81 => Recontextualize from to (t from) (t to)
84instance
85 ( context ~ Expr
86 , Rel8able t
87 , HConstrainTable (Columns (t context)) (ConstrainDBType DBEq)
88 )
89 => EqTable (t context)
90 where
91 eqTable = hdicts @(Columns (t context)) @(ConstrainDBType DBEq)
94instance
95 ( context ~ Expr
96 , Rel8able t
97 , HConstrainTable (Columns (t context)) (ConstrainDBType DBEq)
98 , HConstrainTable (Columns (t context)) (ConstrainDBType DBOrd)
99 )
100 => OrdTable (t context)
101 where
102 ordTable = hdicts @(Columns (t context)) @(ConstrainDBType DBOrd)
105type instance FromExprs (t Expr) = FromExprs' t
108instance
109 ( x ~ t' Expr
110 , result ~ Result
111 , ToExprs' (Algebra t) t' t
112 )
113 => ToExprs x (t result)
114 where
115 fromResult = fromResult' @(Algebra t) @t'
116 toResult = toResult' @(Algebra t) @t'
119type FromExprs' :: K.Rel8able -> Type
120type family FromExprs' t where
121 FromExprs' (ADT t) = t Result
122 FromExprs' (HKD a) = a
123 FromExprs' t = t Result
126type ToExprs' :: K.Algebra -> K.Rel8able -> K.Rel8able -> Constraint
127class (algebra ~ Algebra t, Rel8able t') =>
128 ToExprs' algebra t' t | algebra t -> t'
129 where
130 fromResult' :: GColumns t' (Col Result) -> t Result
131 toResult' :: t Result -> GColumns t' (Col Result)
134instance (Algebra t ~ 'K.Product, Rel8able t, t ~ t') =>
135 ToExprs' 'K.Product t' t
136 where
137 fromResult' = fromColumns
138 toResult' = toColumns
141instance (Algebra t ~ 'K.Sum, ADTable t, t' ~ ADT t) =>
142 ToExprs' 'K.Sum t' t
143 where
144 fromResult' = fromADT . ADT
145 toResult' = (\(ADT a) -> a) . toADT