-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
+emptyState = State{variables=[empty], functions=(empty), function=(Ident "")}
+
+inList :: Eq a => a -> [a] -> Bool
+inList _ [] = False
+inList a (x:xs) = if a == x then True else inList a xs
+
+assert :: Monad m => Bool -> String -> m ()
+assert True _ = return ()
+assert False s = fail s
+
+typeCheckExp :: (MonadState State m) => Exp -> m Type
+typeCheckExp (BiOpExp e o e') = do
+ t1 <- typeCheckExp e
+ t2 <- typeCheckExp e'
+ assert (t1 == t2) "The parameters for the binary operator aren't equal"
+ if inList o [Eq,NEq] then return TBool
+ else do
+ assert (t1 == TInt) "The parameters need to be of type int"
+ if inList o [Plus,Minus,Times,Div]
+ then return TInt
+ else return TBool