implementation module sem
import qualified Data.Map as Map
+
from Data.Func import $
-import Data.Maybe
-import Data.Either
-import Data.Functor
-import Control.Applicative
+from StdFunc import o, flip, const, id
+
import Control.Monad
-import Control.Monad.State
-import Control.Monad.Identity
-import Math.Random
-import Control.Monad.Trans
-import StdMisc
-from StdFunc import id, const, o
+import Data.Either
+import Data.Maybe
+import Data.Monoid
+import Data.List
+
import StdString
-import StdTuple
import StdList
+import StdMisc
+import StdEnum
+import RWST
+import GenEq
from Text import class Text(concat), instance Text String
import AST
-from parse import :: ParserOutput, :: Error
-
-:: Gamma :== ('Map'.Map String Type, [String])
-:: Env a :== StateT Gamma (Either SemError) a
-//StateT (Gamma -> Either SemError (a, Gamma))
-
-//we need to redefine this even though it is in Control.Monad.State
-instance MonadTrans (StateT Gamma) where
- liftT m = StateT \s-> m >>= \a-> return (a, s)
-get = gets id
-
-getRandomStream :: Int -> [String]
-getRandomStream i = genIdents $ filter (isAlpha o toChar) (genRandInt i)
- where
- genIdents r = let (ic, r2) = splitAt 5 r in [toString ic: genIdents r2]
-
-freshIdent :: Env String
-freshIdent = get >>= \(st, [ident:rest])-> put (st, rest)
- >>| case 'Map'.get ident st of
- Nothing = pure ident
- _ = freshIdent
-
-putIdent :: String Type -> Env Void
-putIdent i t = gets (\(st, r)->'Map'.get i st) >>= \mt -> case mt of
- Nothing = modify (\(st, r)->('Map'.put i t st, r))
- Just t2 = unify t t2 >>= \t3-> modify (\(st, r)->('Map'.put i t3 st, r))
-
-instance toString SemError where
- toString (ParseError p e) = concat [
- toString p,"SemError: ParseError: ", e]
- toString (Error e) = "SemError: " +++ e
- toString (UnifyError p t1 t2) = concat [
- toString p,
- "SemError: Cannot unify types. Expected: ",
- toString t1, ". Given: ", toString t2]
- toString (FieldSelectorError p t fs) = concat [
- toString p,
- "SemError: Cannot select ", toString fs, " from type: ",
- toString t]
- toString (OperatorError p o t) = concat [
- toString p,
- "SemError: No ", toString o, " for type ",
- toString t]
- toString (UndeclaredVariableError p ident) = concat [
- toString p, "SemError: identifier: ", ident, " undefined."]
+:: Scheme = Forall [String] Type
+:: Gamma :== 'Map'.Map String Scheme
+:: Constraints :== [(Type, Type)]
+:: Infer a :== RWST Gamma Constraints [String] (Either SemError) a
+:: SemError
+ = ParseError Pos String
+ | UnifyError Pos Type Type
+ | FieldSelectorError Pos Type FieldSelector
+ | OperatorError Pos Op2 Type
+ | UndeclaredVariableError Pos String
+ | ArgumentMisMatchError Pos String
+ | SanityError Pos String
+ | Error String
+
+variableStream :: [String]
+variableStream = map toString [1..]
sem :: AST -> SemOutput
-sem (AST vd fd) = case runStateT m ('Map'.newMap, getRandomStream 1) of
- Left e = Left [e]
- Right ((vds, fds), gamma) = Right ((AST vds fds), gamma)
-where
- m :: Env ([VarDecl], [FunDecl])
- m = mapM semFunDecl fd >>= \fds ->
- mapM semVarDecl vd >>= \vds ->
- pure (vds, fds)
-
-semFunDecl :: FunDecl -> Env FunDecl
-semFunDecl fd=:(FunDecl p f _ mt vds stmts) = case mt of
- Nothing = let t = IdType f in putIdent f t >>| pure fd
- Just t = putIdent f t >>| pure fd
-
-semVarDecl :: VarDecl -> Env VarDecl
-semVarDecl (VarDecl pos type ident ex) = unify type ex
- >>= \t-> putIdent ident t >>| (pure $ VarDecl pos t ident ex)
-
-typeOp2 :: Expr Expr Op2 [Type] Type -> Env Type
-typeOp2 e1 e2 op ts ret = typeExpr e1 >>= \t1-> typeExpr e2 >>= \t2->
- unify t1 t2 >>= \t3->if (isMember t3 ts) (pure ret)
- (liftT $ Left $ OperatorError (extrPos e1) op t3)
-
-typeExpr :: Expr -> Env Type
-typeExpr (IntExpr _ _) = pure IntType
-typeExpr (CharExpr _ _) = pure CharType
-typeExpr (BoolExpr _ _) = pure BoolType
-typeExpr (Op1Expr p UnNegation expr) = unify BoolType expr
-typeExpr (Op1Expr p UnMinus expr) = unify IntType expr
-typeExpr (TupleExpr p (e1, e2)) = typeExpr e1
- >>= \t1-> typeExpr e2 >>= \t2-> pure $ TupleType (t1, t2)
-typeExpr (Op2Expr p e1 op e2)
-| isMember op [BiPlus, BiMinus, BiTimes, BiDivide, BiMod] =
- typeOp2 e1 e2 op [IntType] IntType
-| isMember op [BiEquals, BiUnEqual] =
- typeOp2 e1 e2 op [IntType, BoolType, CharType] BoolType
-| isMember op [BiLesser, BiGreater, BiLesserEq, BiGreaterEq] =
- typeOp2 e1 e2 op [IntType, CharType] BoolType
-| isMember op [BiAnd, BiOr] =
- typeOp2 e1 e2 op [BoolType] BoolType
-| op == BiCons = typeExpr e1 >>= \t1-> typeExpr e2
- >>= \t2-> unify (ListType t1) t2
-typeExpr (EmptyListExpr p) = freshIdent >>= \frsh-> let t = IdType frsh in
- putIdent frsh t >>| pure t
-typeExpr (FunExpr p (FunCall f es)) = gets (\(st, r)->'Map'.get f st)
- >>= \mt-> case mt of
- Nothing = freshIdent >>= \frsh-> buildFunctionType frsh es
- >>= \ft-> putIdent f ft >>| (pure $ IdType frsh)
- Just t = unifyApp t es
-typeExpr (VarExpr p (VarDef ident fs)) = gets (\(st, r)->'Map'.get ident st)
- >>= \mt->case mt of
- Nothing = liftT $ Left $ UndeclaredVariableError p ident
- Just t = unify t fs
-
-buildFunctionType :: String [Expr] -> Env Type
-buildFunctionType frsh [] = let t = IdType frsh in putIdent frsh t >>| pure t
-buildFunctionType frsh [e:es] = (->>) <$> typeExpr e <*> buildFunctionType frsh es
-
-unifyApp :: Type [Expr] -> Env Type
-unifyApp t [] = pure t //whoop whoop, functions can return functions
-unifyApp (tf1 ->> tf2) [t1:ts] = unify tf1 t1 >>| unifyApp tf2 ts
-unifyApp t1 t2 = liftT $ Left $ UnifyError zero t1 (IdType "[expressions, FIXME]")
-
-class unify a :: Type a -> Env Type
-
-instance unify [FieldSelector] where
- unify t [] = pure t
- unify (ListType t) [FieldHd:fs] = unify t fs
- unify t=:(ListType _) [FieldTl:fs] = unify t fs
- unify (TupleType (t, _)) [FieldFst:fs] = unify t fs
- unify (TupleType (_, t)) [FieldSnd:fs] = unify t fs
- unify t [fs:_] = liftT $ Left $ FieldSelectorError zero t fs
-
-instance unify Expr where
- unify (_ ->> _) e = liftT $ Left $ ParseError (extrPos e)
- "Expression cannot be a higher order function. Yet..."
- unify VoidType e = liftT $ Left $ ParseError (extrPos e)
- "Expression cannot be a Void type."
- unify (IdType _) e = liftT $ Left $ ParseError (extrPos e)
- "Expression cannot be an polymorf type."
- unify VarType e = typeExpr e
- unify (IdType i) e = undef
- //we have to cheat to decorate the error, can be done nicer?
- unify t e = StateT $ \s0 -> let res = runStateT m s0 in case res of
- Left err = Left $ decErr e err
- Right t = Right t //note, t :: (Type, Gamma)
- where m = typeExpr e >>= \tex-> unify t tex
-
-replace :: String Type -> Env Void
-replace ident type = get >>= \(st, fr)->put ('Map'.fromList $
- map (itupdate ident type) ('Map'.toList st), fr)
- where
- itupdate :: String Type (String, Type) -> (String, Type)
- itupdate ident newtype ov=:(key, IdType type) = if (ident == type)
- (key, newtype) ov
- itupdate ident newtype (key, TupleType (t1, t2))
- # (_, t1) = itupdate ident newtype (key, t1)
- # (_, t2) = itupdate ident newtype (key, t2)
- = (key, TupleType (t1, t2))
- itupdate ident newtype (key, ListType t1)
- # (_, t1) = itupdate ident newtype (key, t1)
- = (key, ListType t1)
- itupdate _ _ k = k
-
-instance unify Type where
- unify IntType IntType = pure IntType
- unify BoolType BoolType = pure BoolType
- unify CharType CharType = pure CharType
- unify (IdType i) t=:(IdType j) = replace i t >>| pure t
- unify t (IdType i) = unify (IdType i) t
- unify (IdType i) t = replace i t >>| pure t
- unify (ListType t1) (ListType t2) = unify t1 t2 >>| (pure $ ListType t1)
- unify (ta1 ->> ta2) (tb1 ->> tb2) = unify ta1 tb1 >>= \ta-> unify ta2 tb2
- >>= \tb-> pure (ta ->> tb)
- unify t1 t2 = liftT $ Left $ UnifyError zero t1 t2
-
-instance zero Pos where
- zero = {line=0,col=0}
-
-decErr :: Expr SemError -> SemError
-decErr e (UnifyError _ t1 t2) = UnifyError (extrPos e) t1 t2
-decErr e (FieldSelectorError _ t fs) = FieldSelectorError (extrPos e) t fs
-decErr e (ParseError _ s) = ParseError (extrPos e) s
-decErr e err = err
-
-dc2 :: Expr (Either SemError a) -> Either SemError a
-dc2 e (Right t) = Right t
-dc2 e (Left err) = Left err
-
-extrPos :: Expr -> Pos
-extrPos (VarExpr p _) = p
-extrPos (Op2Expr p _ _ _) = p
-extrPos (Op1Expr p _ _) = p
-extrPos (IntExpr p _) = p
-extrPos (CharExpr p _) = p
-extrPos (BoolExpr p _) = p
-extrPos (FunExpr p _) = p
-extrPos (EmptyListExpr p) = p
-extrPos (TupleExpr p _) = p
+sem a=:(AST fd) = case foldM (const $ hasNoDups fd) () fd
+ >>| foldM (const isNiceMain) () fd
+ >>| hasMain fd of
+ Left e = Left [e]
+ _ = pure (a, 'Map'.newMap)
+where
+ hasNoDups :: [FunDecl] FunDecl -> Either SemError ()
+ hasNoDups fds (FunDecl p n _ _ _ _)
+ # mbs = map (\(FunDecl p` n` _ _ _ _)->if (n == n`) (Just p`) Nothing) fds
+ = case catMaybes mbs of
+ [] = Left $ SanityError p "HUH THIS SHOULDN'T HAPPEN"
+ [x] = pure ()
+ [_:x] = Left $ SanityError p (concat
+ [n, " multiply defined at ", toString p])
+
+ hasMain :: [FunDecl] -> Either SemError ()
+ hasMain [(FunDecl _ "main" _ _ _ _):fd] = pure ()
+ hasMain [_:fd] = hasMain fd
+ hasMain [] = Left $ SanityError zero "no main function defined"
+
+ isNiceMain :: FunDecl -> Either SemError ()
+ isNiceMain (FunDecl p "main" as mt _ _) = case (as, mt) of
+ ([_:_], _) = Left $ SanityError p "main must have arity 0"
+ ([], t) = (case t of
+ Nothing = pure ()
+ Just VoidType = pure ()
+ _ = Left $ SanityError p "main has to return Void")
+ isNiceMain _ = pure ()
+
+instance toString Scheme where
+ toString (Forall x t) =
+ concat ["Forall ": map ((+++) "\n") x] +++ toString t
instance toString Gamma where
- toString (mp, _) = concat
- [concat [k, ": ", toString v, "\n"]\\(k, v) <- 'Map'.toList mp]
+ toString mp =
+ concat [concat [k, ": ", toString v, "\n"]\\(k, v)<-'Map'.toList mp]
+instance toString SemError where
+ toString (SanityError p e) = concat [toString p,
+ "SemError: SanityError: ", e]
+ toString se = "SemError: "
-// class free a :: a -> Env [a]
+uni :: Type Type -> Infer ()
+uni t1 t2 = tell [(t1, t2)]
+
+inEnv :: (String, Scheme) (Infer a) -> (Infer a)
+inEnv (x, sc) m = local scope m
+ where
+ scope e = 'Map'.put x sc ('Map'.del x e )
+
+fresh :: Infer Type
+fresh = (gets id) >>= \vars-> (put $ tail vars) >>| (pure $ IdType $ head vars)
+
+class infer a :: a -> Infer Type
+
+op2Type :: Op2 -> Infer Type
+op2Type op | elem op [BiPlus, BiMinus, BiTimes, BiDivide, BiMod]
+ = pure (IntType ->> IntType ->> IntType)
+ | elem op [BiEquals, BiUnEqual]
+ = fresh >>= \t1-> fresh >>= \t2-> pure (t1 ->> t2 ->> BoolType)
+ | elem op [BiLesser, BiGreater, BiLesserEq, BiGreaterEq]
+ = pure (IntType ->> IntType ->> BoolType)
+ | elem op [BiAnd, BiOr]
+ = pure (BoolType ->> BoolType ->> BoolType)
+ | op == BiCons
+ = fresh >>= \t1-> pure (t1 ->> ListType t1 ->> ListType t1)
+
+op1Type :: Op1 -> Infer Type
+op1Type UnNegation = pure $ (BoolType ->> BoolType)
+op1Type UnMinus = pure $ (IntType ->> IntType)
+
+instance infer Expr where
+ infer (VarExpr _ vd) = undef
+ infer (Op2Expr _ e1 op e2) = case op of
+ BiPlus = pure IntType
+ BiMinus = pure IntType
+ BiTimes = pure IntType
+ BiDivide = pure IntType
+ BiMod = pure IntType
+ BiLesser = pure IntType
+ BiGreater = pure IntType
+ BiLesserEq = pure IntType
+ BiGreaterEq = pure IntType
+ BiAnd = pure BoolType
+ BiOr = pure BoolType
+ BiEquals = infer e1
+ BiUnEqual = infer e1 // maybe check e2?
+ BiCons = infer e1 >>= \it1->pure $ ListType it1
+ infer (Op1Expr _ op e) = case op of
+ UnMinus = pure IntType
+ UnNegation = pure BoolType
+ infer (IntExpr _ _) = pure IntType
+ infer (CharExpr _ _) = pure CharType
+ infer (BoolExpr _ _) = pure BoolType
+ infer (FunExpr _ _ _ _) = undef
+ infer (EmptyListExpr _) = undef
+ infer (TupleExpr _ (e1, e2)) =
+ infer e1 >>= \et1->infer e2 >>= \et2->pure $ TupleType (et1, et2)
+
+//:: VarDef = VarDef String [FieldSelector]
+//:: FieldSelector = FieldHd | FieldTl | FieldFst | FieldSnd
+//:: Op1 = UnNegation | UnMinus
+//:: Op2 = BiPlus | BiMinus | BiTimes | BiDivide | BiMod | BiEquals | BiLesser |
+// BiGreater | BiLesserEq | BiGreaterEq | BiUnEqual | BiAnd | BiOr | BiCons
+//:: FunDecl = FunDecl Pos String [String] (Maybe Type) [VarDecl] [Stmt]
+//:: FunCall = FunCall String [Expr]
+//:: Stmt
+// = IfStmt Expr [Stmt] [Stmt]
+// | WhileStmt Expr [Stmt]
+// | AssStmt VarDef Expr
+// | FunStmt FunCall
+// | ReturnStmt (Maybe Expr)
+//:: Pos = {line :: Int, col :: Int}
+//:: AST = AST [VarDecl] [FunDecl]
+//:: VarDecl = VarDecl Pos Type String Expr
+//:: Type
+// = TupleType (Type, Type)
+// | ListType Type
+// | IdType String
+// | IntType
+// | BoolType
+// | CharType
+// | VarType
+// | VoidType
+// | (->>) infixl 7 Type Type
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