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module CC.AST.Typed(
module CC.AST.Typed,
module CC.Types
) where
import qualified Data.Map.Strict as Map
import Data.Map.Strict (Map)
import qualified Data.Set as Set
import Data.Set (Set)
import Data.List
import CC.Pretty
import CC.Types
data Program = Program [Def] (Map Name TypeDef)
deriving (Show, Read)
data Def = Def Name Expr
deriving (Show, Read)
-- Named type with type parameters
data TypeDef = TypeDef Name [Int] Type
deriving (Show, Read)
data Type = TFun Type Type
| TInt
| TTup [Type]
| TNamed Name [Type] -- named type with type arguments
| TUnion (Set Type)
| TyVar Rigidity Int
deriving (Eq, Ord, Show, Read)
data Rigidity = Rigid | Instantiable
deriving (Eq, Ord, Show, Read)
data TypeScheme = TypeScheme [Int] Type
deriving (Show, Read)
data Expr = Lam Type Occ Expr
| Let Occ Expr Expr
| Call Type Expr Expr
| Int Int
| Tup [Expr]
| Var Occ
| Constr Type Name -- Type is 'argument -> TNamed'
deriving (Show, Read)
data Occ = Occ Name Type
deriving (Show, Read)
exprType :: Expr -> Type
exprType (Lam typ _ _) = typ
exprType (Let _ _ body) = exprType body
exprType (Call typ _ _) = typ
exprType (Int _) = TInt
exprType (Tup es) = TTup (map exprType es)
exprType (Var (Occ _ typ)) = typ
exprType (Constr typ _) = typ
instance Pretty Type where
prettyPrec _ TInt = "Int"
prettyPrec p (TFun a b) =
precParens p 2 (prettyPrec 3 a ++ " -> " ++ prettyPrec 2 b)
prettyPrec _ (TTup ts) =
"(" ++ intercalate ", " (map pretty ts) ++ ")"
prettyPrec _ (TNamed n ts) =
n ++ "[" ++ intercalate ", " (map pretty ts) ++ "]"
prettyPrec _ (TUnion ts) =
"{ " ++ intercalate " | " (map pretty (Set.toList ts)) ++ " }"
prettyPrec _ (TyVar Rigid i) = 't' : show i ++ "R"
prettyPrec _ (TyVar Instantiable i) = 't' : show i
instance Pretty TypeScheme where
prettyPrec p (TypeScheme bnds ty) =
precParens p 2
("forall " ++ intercalate " " (map (pretty . TyVar Instantiable) bnds) ++
". " ++ prettyPrec 2 ty)
instance Pretty Expr where
prettyPrec p (Lam ty (Occ n t) e) =
precParens p 2 $
"(\\(" ++ n ++ " :: " ++ pretty t ++ ") -> "
++ prettyPrec 2 e ++ ") :: " ++ pretty ty
prettyPrec p (Let (Occ n t) rhs e) =
precParens p 2 $
"let (" ++ n ++ " :: " ++ pretty t ++ ") = " ++ pretty rhs ++ " " ++
(case e of
Let _ _ _ -> pretty e
_ -> "in " ++ pretty e)
prettyPrec p (Call ty e1 e2) =
precParens p 2 $
prettyPrec 3 e1 ++ " " ++ prettyPrec 3 e2 ++ " :: " ++ pretty ty
prettyPrec _ (Int i) = show i
prettyPrec _ (Tup es) = "(" ++ intercalate ", " (map pretty es) ++ ")"
prettyPrec p (Var (Occ n t)) =
precParens p 2 $
n ++ " :: " ++ pretty t
prettyPrec p (Constr t n) =
precParens p 2 $
n ++ " :: " ++ pretty t
instance Pretty Def where
pretty (Def n e) = n ++ " = " ++ pretty e
instance Pretty TypeDef where
pretty (TypeDef n [] t) =
"type " ++ n ++ " = " ++ pretty t
pretty (TypeDef n vs t) =
"type " ++ n ++ " " ++ intercalate " " (map (pretty . TyVar Instantiable) vs) ++
" = " ++ pretty t
instance Pretty Program where
pretty (Program defs tdefs) =
concatMap (++ "\n") $
map pretty (Map.elems tdefs) ++ map pretty defs
|
