added some type checking stuff. vardecl now works for basictypes and unary operators

[cc1516.git] / sem.icl

diff --git a/sem.icl b/sem.icl
index 667b6eb..7132135 100644 (file)
--- a/sem.icl
+++ b/sem.icl
@@ -35,6 +35,7 @@ instance toString SemError where
        toString (ParseError p e) = concat [
                toString p,"SemError: ParseError: ", e]
        toString (Error e) = "SemError: " +++ e
+       toString (UnifyErrorStub t1 t2) = toString (UnifyError {line=0,col=0} t1 t2)
        toString (UnifyError p t1 t2) = concat [
                toString p,
                "SemError: Cannot unify types. Expected: ",
@@ -59,18 +60,15 @@ semFunDecl :: FunDecl -> Env FunDecl
 semFunDecl f = pure $ Right f
 
 semVarDecl :: VarDecl -> Env VarDecl
-semVarDecl v = pure $ Right v
+semVarDecl vd=:(VarDecl pos type ident ex) = unify type ex
+       >>= \et->pure (
+               et >>= \t->pure $ VarDecl pos t ident ex)
 //Right v
-//semVarDecl vd=:(VarDecl pos type ident expr) = case unify type expr of //    Left e = Left e
 //     //TODO ident in de environment
 //     Right e = Right $ pure vd
 
 typeOp1 :: Pos Expr Type -> Env Type
-typeOp1 p expr rtype = typeExpr expr >>= \exprtype->case exprtype of
-       Left e = pure $ Left e
-       Right rtype = pure $ Right rtype
-       Right (IdType ident) = putIdent ident rtype >>| pure (Right rtype)
-       Right t = pure $ Left $ UnifyError p rtype t
+typeOp1 p expr rtype = unify rtype expr
 
 typeExpr :: Expr -> Env Type
 typeExpr (IntExpr _ _) = pure $ Right IntType
@@ -81,10 +79,6 @@ typeExpr (Op1Expr p UnMinus expr) = typeOp1 p expr IntType
 typeExpr (TupleExpr p (e1, e2)) = typeExpr e1 
        >>= \ete1->typeExpr e2 >>= \ete2->pure (
                ete1 >>= \te1->ete2 >>= \te2->Right $ TupleType (te1, te2))
-//typeExpr (Op1Expr p UnMinus expr) = typeExpr expr 
-//     >>= \exprtype->case exprtype of
-//             IntType = pure $ Right IntType
-//             t = Left $ UnifyError p IntType exprtype
 //typeExpr (Op2Expr Pos Expr Op2 Expr) = undef
 //typeExpr (FunExpr Pos FunCall) = undef
 //typeExpr (EmptyListExpr Pos) = undef
@@ -92,23 +86,41 @@ typeExpr (TupleExpr p (e1, e2)) = typeExpr e1
 
 class unify a :: Type a -> Env Type
 
+instance unify Expr where
+       unify (_ ->> _) e = pure $ Left $ ParseError (extrPos e)
+                       "Expression cannot be a higher order function. Yet..."
+       unify VoidType e = pure $ Left $ ParseError (extrPos e)
+                       "Expression cannot be a Void type."
+       unify (IdType _) e = pure $ Left $ ParseError (extrPos e)
+                       "Expression cannot be an polymorf type."
+       unify t e = typeExpr e
+               >>= \eithertype->case eithertype of
+                       Left e = pure $ Left e
+                       Right tex = unify t tex >>= \eitherun->case eitherun of
+                               Left err = pure $ Left $ decErr e err
+                               Right t = pure $ Right t
+
 instance unify Type where
        unify IntType IntType = pure $ Right IntType
        unify BoolType BoolType = pure $ Right BoolType
        unify CharType CharType = pure $ Right CharType
-       unify _ _ = undef
-//
-//instance unify Expr where
-//     unify type expr = case type of
-//             _ ->> _ = Left $ ParseError (extrPos expr)
-//                     "Expression cannot be a higher order function. Yet..."
-//             VoidType = Left $ ParseError (extrPos expr)
-//                     "Expression cannot be a Void type."
-//             IdType _ = Left $ ParseError (extrPos expr)
-//                     "Expression cannot be an polymorf type."
-//             TupleType (_, _) = undef
-//             ListType _ = undef
-//             IntType = undef
-//             BoolType = undef
-//             CharType = undef
-//             VarType = undef
+       unify t1 t2 = pure $ 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 (ParseError _ s) = ParseError (extrPos e) s
+decErr e err = 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