All expression can now be typed.

Functions are now typed before expressions. This gives the program the form
let <fundecls> in <vardecls>

This leaves stuff such as mutal rucursion etc.

diff --git a/AST.dcl b/AST.dcl
index 4fd4121..cb2e5b7 100644 (file)
--- a/AST.dcl
+++ b/AST.dcl
@@ -1,7 +1,7 @@
 definition module AST
 
 from Data.Maybe import :: Maybe
-from StdOverloaded import class toString
+from StdOverloaded import class toString, class ==
 
 :: Pos = {line :: Int, col :: Int}
 :: AST = AST [VarDecl] [FunDecl]

diff --git a/sem.icl b/sem.icl
index c7a41e9..2dc487f 100644 (file)
--- a/sem.icl
+++ b/sem.icl
@@ -73,8 +73,8 @@ sem (AST vd fd) = case runStateT m ('Map'.newMap, getRandomStream 1) of
     Right ((vds, fds), gamma) = Right ((AST vds fds), gamma)
 where 
     m :: Env ([VarDecl], [FunDecl])
-    m = (mapM semVarDecl vd) >>= \vds -> 
-        mapM semFunDecl fd >>= \fds -> 
+    m = mapM semFunDecl fd >>= \fds -> 
+        mapM semVarDecl vd >>= \vds -> 
         pure (vds, fds)
 
 semFunDecl :: FunDecl -> Env FunDecl
@@ -86,9 +86,9 @@ 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] -> Env Type
-typeOp2 e1 e2 op ts = typeExpr e1 >>= \t1-> typeExpr e2 >>= \t2->
-       unify t1 t2     >>= \t3->if (isMember t3 ts) (pure t3)
+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
@@ -101,31 +101,35 @@ 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]
+       typeOp2 e1 e2 op [IntType] IntType
 | isMember op [BiEquals, BiUnEqual] =
-       typeOp2 e1 e2 op [IntType, BoolType, CharType]
+       typeOp2 e1 e2 op [IntType, BoolType, CharType] BoolType
 | isMember op [BiLesser, BiGreater, BiLesserEq, BiGreaterEq] =
-       typeOp2 e1 e2 op [IntType, CharType]
+       typeOp2 e1 e2 op [IntType, CharType] BoolType
 | isMember op [BiAnd, BiOr] =
-       typeOp2 e1 e2 op [BoolType]
+       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
-//ignore field selectors
 typeExpr (FunExpr p (FunCall f es)) = gets (\(st, r)->'Map'.get f st)
     >>= \mt-> case mt of
-        Nothing = let t = IdType f in putIdent f t >>| pure t
+        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")
+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
 
@@ -176,6 +180,8 @@ instance unify Type where
     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