minor change

[proglang.git] / Typecheck.hs

diff --git a/Typecheck.hs b/Typecheck.hs
index a701b6e85bf92a0e9f0807251e5eecbfa83c7592..a8c10e55f5dc570e99e79fd9b30b9ad085664d11 100644 (file)
--- a/Typecheck.hs
+++ b/Typecheck.hs
@@ -1,4 +1,4 @@
-module Typecheck (typeCheckExp, typeCheckStm, typeCheckVar, typeCheckFunction, addFunction, emptyState, State(..)) where 
+module Typecheck (typeCheck, typeCheckExp, typeCheckStm, typeCheckVar, typeCheckFunction, addFunction, emptyState, State(..)) where 
 
 
 import Abssyntax
@@ -13,23 +13,24 @@ data State = State {variables::Types,functions::(Map Ident Function),function::I
 
 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
 
+typeCheck :: [Func] -> [Stm] -> IO ()
+typeCheck fun st = do
+       runStateT (do mapM addFunction fun; mapM typeCheckFunction fun; mapM typeCheckStm st) emptyState
+       return ()
+
 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
+       if elem 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]
+                       if elem o [Plus,Minus,Times,Div]
                                then return TInt
                                else return TBool
 typeCheckExp (EVar i) = typeCheckVar i
@@ -121,6 +122,9 @@ typeCheckFunction (Func t i d s) = do
        state <- get
        modify (\s -> s{variables=[empty], function=i})
        mapM (\(Decl t i) -> addVariable i t) d
+       case last s of
+               (SReturn _) -> return ()
+               _ -> fail $ "Function "++show i++" doesn't end with return statement"
        mapM typeCheckStm s
        put state