Files
rlp/src/Core/Syntax.hs
2024-02-06 13:39:01 -07:00

218 lines
5.5 KiB
Haskell

{-|
Module : Core.Syntax
Description : Core ASTs and the like
-}
{-# LANGUAGE PatternSynonyms, OverloadedStrings #-}
{-# LANGUAGE FunctionalDependencies #-}
{-# LANGUAGE TemplateHaskell #-}
{-# LANGUAGE DerivingStrategies, DerivingVia #-}
-- for recursion-schemes
{-# LANGUAGE DeriveFunctor, DeriveFoldable, DeriveTraversable
, TemplateHaskell, TypeFamilies #-}
module Core.Syntax
( Expr(..)
, ExprF(..)
, ExprF'(..)
, Type(..)
, pattern TyInt
, Lit(..)
, pattern (:$)
, pattern (:@)
, pattern (:->)
, Binding(..)
, AltCon(..)
, pattern (:=)
, Rec(..)
, Alter(..)
, Name
, Tag
, ScDef(..)
, Module(..)
, Program(..)
, Program'
, Pragma(..)
, unliftScDef
, programScDefs
, programTypeSigs
, programDataTags
, Expr'
, ScDef'
, Alter'
, Binding'
, HasRHS(_rhs)
, HasLHS(_lhs)
)
where
----------------------------------------------------------------------------------
import Data.Coerce
import Data.Pretty
import Data.List (intersperse)
import Data.Function ((&))
import Data.Functor.Foldable
import Data.Functor.Foldable.TH (makeBaseFunctor)
import Data.String
import Data.HashMap.Strict (HashMap)
import Data.HashMap.Strict qualified as H
import Data.Hashable
import Data.Text qualified as T
import Data.Char
import GHC.Generics
-- Lift instances for the Core quasiquoters
import Language.Haskell.TH.Syntax (Lift)
-- import Lens.Micro.TH (makeLenses)
-- import Lens.Micro
import Control.Lens
----------------------------------------------------------------------------------
data Expr b = Var Name
| Con Tag Int -- ^ Con Tag Arity
| Case (Expr b) [Alter b]
| Lam [b] (Expr b)
| Let Rec [Binding b] (Expr b)
| App (Expr b) (Expr b)
| Lit Lit
deriving (Show, Read, Lift)
deriving instance (Eq b) => Eq (Expr b)
data Type = TyFun
| TyVar Name
| TyApp Type Type
| TyCon Name
deriving (Show, Read, Lift, Eq)
pattern TyInt :: Type
pattern TyInt = TyCon "Int#"
infixl 2 :$
pattern (:$) :: Expr b -> Expr b -> Expr b
pattern f :$ x = App f x
infixl 2 :@
pattern (:@) :: Type -> Type -> Type
pattern f :@ x = TyApp f x
infixr 1 :->
pattern (:->) :: Type -> Type -> Type
pattern a :-> b = TyApp (TyApp TyFun a) b
{-# COMPLETE Binding :: Binding #-}
{-# COMPLETE (:=) :: Binding #-}
data Binding b = Binding b (Expr b)
deriving (Show, Read, Lift)
deriving instance (Eq b) => Eq (Binding b)
infixl 1 :=
pattern (:=) :: b -> Expr b -> Binding b
pattern k := v = Binding k v
data Alter b = Alter AltCon [b] (Expr b)
deriving (Show, Read, Lift)
deriving instance (Eq b) => Eq (Alter b)
newtype Pragma = Pragma [T.Text]
data Rec = Rec
| NonRec
deriving (Show, Read, Eq, Lift)
data AltCon = AltData Name
| AltTag Tag
| AltLit Lit
| AltDefault
deriving (Show, Read, Eq, Lift)
newtype Lit = IntL Int
deriving (Show, Read, Eq, Lift)
type Name = T.Text
type Tag = Int
data ScDef b = ScDef b [b] (Expr b)
deriving (Show, Lift)
unliftScDef :: ScDef b -> Expr b
unliftScDef (ScDef _ as e) = Lam as e
data Module b = Module (Maybe (Name, [Name])) (Program b)
deriving (Show, Lift)
data Program b = Program
{ _programScDefs :: [ScDef b]
, _programTypeSigs :: HashMap b Type
-- map constructors to their tag and arity
, _programDataTags :: HashMap b (Tag, Int)
}
deriving (Show, Lift, Generic)
deriving (Semigroup, Monoid)
via Generically (Program b)
makeLenses ''Program
makeBaseFunctor ''Expr
pure []
-- this is a weird optic, stronger than Lens and Prism, but weaker than Iso.
programTypeSigsP :: (Hashable b) => Prism' (Program b) (HashMap b Type)
programTypeSigsP = prism
(\b -> mempty & programTypeSigs .~ b)
(Right . view programTypeSigs)
type ExprF' = ExprF Name
type Program' = Program Name
type Expr' = Expr Name
type ScDef' = ScDef Name
type Alter' = Alter Name
type Binding' = Binding Name
instance IsString (Expr b) where
fromString = Var . fromString
instance IsString Type where
fromString "" = error "IsString Type string may not be empty"
fromString s
| isUpper c = TyCon . fromString $ s
| otherwise = TyVar . fromString $ s
where (c:_) = s
----------------------------------------------------------------------------------
class HasRHS s t a b | s -> a, t -> b, s b -> t, t a -> s where
_rhs :: Lens s t a b
instance HasRHS (Alter b) (Alter b) (Expr b) (Expr b) where
_rhs = lens
(\ (Alter _ _ e) -> e)
(\ (Alter t as _) e' -> Alter t as e')
instance HasRHS (ScDef b) (ScDef b) (Expr b) (Expr b) where
_rhs = lens
(\ (ScDef _ _ e) -> e)
(\ (ScDef n as _) e' -> ScDef n as e')
instance HasRHS (Binding b) (Binding b) (Expr b) (Expr b) where
_rhs = lens
(\ (_ := e) -> e)
(\ (k := _) e' -> k := e')
class HasLHS s t a b | s -> a, t -> b, s b -> t, t a -> s where
_lhs :: Lens s t a b
instance HasLHS (Alter b) (Alter b) (AltCon, [b]) (AltCon, [b]) where
_lhs = lens
(\ (Alter a bs _) -> (a,bs))
(\ (Alter _ _ e) (a',bs') -> Alter a' bs' e)
instance HasLHS (ScDef b) (ScDef b) (b, [b]) (b, [b]) where
_lhs = lens
(\ (ScDef n as _) -> (n,as))
(\ (ScDef _ _ e) (n',as') -> ScDef n' as' e)
instance HasLHS (Binding b) (Binding b) b b where
_lhs = lens
(\ (k := _) -> k)
(\ (_ := e) k' -> k' := e)