X-Git-Url: https://ruin.nu/git/?p=proglang.git;a=blobdiff_plain;f=Typecheck.hs;h=6e845ba2cb56b9625570676c65e6354da53eb4ba;hp=ec2270e01c3860215b28dcb851807b8f8f14ea99;hb=6103c0359b95557566aa9154efa5bcd4d9c996f6;hpb=9726c329b6d9ab02a1b50566ae96c82f29c5ec4d

diff --git a/Typecheck.hs b/Typecheck.hs
index ec2270e..6e845ba 100644
--- a/Typecheck.hs
+++ b/Typecheck.hs
@@ -1,4 +1,4 @@
-module Typecheck where 
+module Typecheck (typeCheckExp, typeCheckStm, typeCheckVar) where 
 
 import Abssyntax
 import Control.Monad.State
@@ -8,15 +8,21 @@ import Prelude hiding (lookup)
 
 type Types = Map Ident Type
 
+inList :: Eq a => a -> [a] -> Bool
+inList _ [] = False
+inList a (x:xs) = if a == x then True else inList a xs
+
 typeCheckExp :: (MonadState Types m) => Exp -> m Type
-typeCheckExp (BExp e o e') = do
-	TInt <- typeCheckExp e
-	TInt <- typeCheckExp e'
-	return TBool
-typeCheckExp (OpExp e o e') = do
-	TInt <- typeCheckExp e
-	TInt <- typeCheckExp e'
-	return TInt
+typeCheckExp (BiOpExp e o e') = do
+	t1 <- typeCheckExp e
+	t2 <- typeCheckExp e'
+	if not(t1 == t2) then fail "" 
+		else case inList o [Eq,NEq] of
+			True -> return TBool
+			False -> if not(t1 == TInt) then fail "" 
+				else case inList o [Plus,Minus,Times,Div] of
+					True -> return TInt
+					False -> return TBool
 typeCheckExp (EVar i) = typeCheckVar i
 typeCheckExp (EAss i e) = do
 	a <- typeCheckVar i
@@ -33,6 +39,9 @@ typeCheckExp EDefault = return NoType
 typeCheckExp (EPost i op) = do
 	TInt <- typeCheckVar i
 	return TInt
+typeCheckExp (ENeg e) = do
+	TInt <- typeCheckExp e
+	return TInt
 
 
 typeCheckVar :: (MonadState Types m) => Ident -> m Type 
@@ -59,11 +68,11 @@ typeCheckStm (SWhile e s) = do
 	return NoType
 typeCheckStm (SDecl t i e) = do
 	t2 <- typeCheckExp e
-	if t == t2 then do
+	if t == t2 || t2 == NoType then do
 		m <- get
 		put (insert i t m)
 		return NoType
-		else fail "Så får du inte göra!!!"
+		else fail $ "Illegal to assign an expression of type "++show t2++" to variable "++show i++" of type "++show t
 typeCheckStm (SPrint e) = do
 	typeCheckExp e
 	return NoType