* refactor: major environment mgmt refactor
This big refactor primarily changes two things in terms of behavior:
1. Stores a SymPath on concretely named (non-generic) struct types;
before we stored a string.
2. The SymPath mentioned in (1.) designates where the struct is stored
in the current environment chain. Modules now carry a local type
environment in addition to their local value environments. Any types
defined in the module are added to this environment rather than the
global type environment.
To resolve a type such as `Foo.Bar` we now do the following:
- Search the *global value environment* for the Foo module.
- Get the type environment stored in the Foo module.
- Search for Bar in the Foo module's type environment.
Additionally, this commit eliminates the Lookup module entirely and
refactors the Env module to handle all aspects of environment management
in hopefully a more reusable fashion.
I also took the opportunity to refactor primitiveDeftype in Primitives
and qualifySym in Qualify, both of which were hefty functions that I
found difficult to grok and needed refactoring anyway as a result of
lookup changes (lookups now return an Either instead of a Maybe).
Subsequent commits will clean up and clarify this work further.
This does include one minor regression. Namely, an implementation of
`hash` in core/Color that was maximally generic now needs type casting.
* refactor: clean up recent Env changes
This commit removes some redundant functions, unifies some logic, and
renames some routines across the Env module in efforts to make it
cleaner. Call sites have been updated accordingly.
* chore: format code with ormolu
* fix: update lookup tests
Changes references to renamed functions in the Env module.
* refactor: style + additional improvements from eriksvedang@
- Rename arrayTy -> arrayTyA in ArrayTemplates.hs to disambiguate.
- Add maybeId util function.
- Remove commented code.
- Refactor a few functions for readability.
* fix: fix type inference regression
Recent commits introduced one minor regression whereby an instance of
type inference in core/Color.carp no longer worked and required
explicit type annotation. The problem ultimately had to do with
qualification:
- Prior to the recent changes, type inference worked because the call in
question was qualified to Color.Id.get-tag, fixing the type.
- Failing to copy over a local envs Use modules to function envs
resulted in finding more than just Color.Id.get-tag for this instance.
We now copy use modules over to function envs generated during
qualification to ensure we resolve to Use'd definitions before more
general cases.
Similarly, I made a small change to primitiveUse to support contextual
use calls (e.g. the `(use Id)` in Color.carp, which really means `(use
Color.Id)`)
* chore: Update some clarificatory comments
* chore: fix inline comment
Extends Carp's support for type reflection by returning types for
values as well as bindings.
`type` now also returns a valid Carp expression/s-expression and so its
output can be used as input to dynamic functions and macros (prior to
this commit, `type` printed the type to the REPL but did not return a
meaningful expression in Carp).
Here are a few illustrations of the behavior:
```
(def x 1)
;; type now returns an s-expression/symbol
(type x)
=> Int
;; It also works on values
(type 1)
=> Int
(type 2b)
=> Byte
(type "foo")
=> (Ref String <StaticLifetime>)
;; It works on more complex values as well
(type Maybe)
=> Module
(type Maybe.Just)
(Fn [a] (Maybe a) <StaticLifetime>)
;; reports honestly about polymorphism
(type (Maybe.Nothing))
=> (Maybe a)
(type (Pair.init 1 2))
=> (Pair Int Int)
;; What about the type of types?
(type (type 2))
=> Type
;; Or the type of types of types?
(type (type (type 2)))
=> ()
;; One more time!
(type (type (type (type 2))))
=> ()
;; so, () is the fixpoint of type, and is reached after two applications
(type zero)
;; the type of an interface is all of its implementations
=> (((Fn [] (Array a) <StaticLifetime>) (Fn [] Bool <StaticLifetime>) (Fn
[] Byte <StaticLifetime>) (Fn [] Char <StaticLifetime>) (Fn [] Double
<StaticLifetime>) (Fn [] Float <StaticLifetime>) (Fn [] Int
<StaticLifetime>) (Fn [] Int16 <StaticLifetime>) (Fn [] Int32
<StaticLifetime>) (Fn [] Int64 <StaticLifetime>) (Fn [] Int8
<StaticLifetime>) (Fn [] Long <StaticLifetime>) (Fn [] (Maybe a)
<StaticLifetime>) (Fn [] (Pair a b) <StaticLifetime>) (Fn [] (Quadruple
a b c d) <StaticLifetime>) (Fn [] String <StaticLifetime>) (Fn []
(Triple a b c) <StaticLifetime>) (Fn [] Uint16 <StaticLifetime>) (Fn []
Uint32 <StaticLifetime>) (Fn [] Uint64 <StaticLifetime>) (Fn [] Uint8
<StaticLifetime>)))
```
As shown in the example above, this change also includes a cosmetic
update to the representation of lifetime variables, which are surrounded
in <> to distinguish them from type variables.
This commit also adds a new `kind` primitive that reports on the kind of
a binding or value:
```
(def x 3)
(kind x)
=> Base
(kind 2)
=> Base
(kind Maybe.Just)
=> Higher
(kind (Maybe.Just 2))
=> Higher
```
`kind` and `type` both support interactive development in the repl, for
example, a user can rely on `kind` to check the kind of a type they plan
on using in an interface that demands a higher-kinded argument.
Likewise, they both also support developing macros based on type
information.