X-Git-Url: https://ruin.nu/git/?a=blobdiff_plain;f=Typecheck.hs;h=29008bd2213c250a487f7c303287e3f245c445b7;hb=ff80cbdaf843e2745f59e6f5d3c8670cadbf68b2;hp=6f65d6e2f538d18d554787225c4aa138918a586f;hpb=ef4659dbfa5051372cf067f8c0ed2bbe77146650;p=proglang.git

diff --git a/Typecheck.hs b/Typecheck.hs
index 6f65d6e..29008bd 100644
--- a/Typecheck.hs
+++ b/Typecheck.hs
@@ -1,40 +1,46 @@
-module Typecheck (typeCheckExp, typeCheckStm, typeCheckVar) where 
+module Typecheck where -- (typeCheckExp, typeCheckStm, typeCheckVar, State) where 
 
 
 import Abssyntax
-import Control.Monad.State
+import Control.Monad.State hiding (State)
 import Data.Map as Map
 import Prelude hiding (lookup)
 
 type Types = [Map Ident Type]
+type Function = (Type, [Type])
+
+data State = State {variables::Types,functions::[Map Ident Function],function::Ident}
+
 
 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
+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'
-	if not(t1 == t2) then fail "The parameters for the binary operator aren't equal" 
-		else if inList o [Eq,NEq] then return TBool
-			else if not(t1 == TInt) then fail "The parameters need to be of type int" 
-				else if inList o [Plus,Minus,Times,Div]
-					then return TInt
-					else return TBool
+	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
 typeCheckExp (EVar i) = typeCheckVar i
 typeCheckExp (EAss i e) = do
 	t <- typeCheckVar i
 	t2 <- typeCheckExp e
-	if t == t2 then return t else fail $ "Illegal to assign an expression of type "++show t2++" to variable "++show i++" of type "++show t 
+	assert (t == t2) $ "Illegal to assign an expression of type "++show t2++" to variable "++show i++" of type "++show t 
+	return t
 typeCheckExp (EInt i) = return TInt
 typeCheckExp (EBool b) = return TBool
 typeCheckExp EReadI = return TInt
 typeCheckExp EReadB = return TBool
-typeCheckExp (ExpT t e) = do
-	t2 <- typeCheckExp e
-	if t == t2 then return t else fail "Something went wrong ExpT is created with the wrong type"
-typeCheckExp EDefault = return NoType
 typeCheckExp (EPost i op) = do
 	TInt <- typeCheckVar i
 	return TInt
@@ -45,43 +51,46 @@ typeCheckExp (ENot e) = do
 	TBool <- typeCheckExp e
 	return TBool
 
-typeCheckVar :: (MonadState Types m) => Ident -> m Type 
+typeCheckVar :: (MonadState State m) => Ident -> m Type 
 typeCheckVar i = do
-	ms <- get
-	findVariable i ms
+	s <- get
+	findVariable i $ variables s
 
-findVariable :: (MonadState Types m) => Ident -> Types -> m Type
+findVariable :: (MonadState State m) => Ident -> Types -> m Type
 findVariable i [] = fail $ "Variable "++show i++" not found in any scope."
 findVariable i (m:ms) = if member i m then lookup i m else findVariable i ms
 
-typeCheckStm :: (MonadState Types m) => Stm -> m Type 
-typeCheckStm SNoop = return NoType
+pushAndPop :: (MonadState State m) => m a -> m ()
+pushAndPop s = do
+	modify (\s -> s { variables = empty:variables s})
+	s
+	modify (\s -> s { variables = tail $ variables s})
+
+typeCheckStm :: (MonadState State m) => Stm -> m ()
+typeCheckStm SNoop = return ()
 typeCheckStm (SExp e) = do 
 	typeCheckExp e
-	return NoType
-typeCheckStm (SBlock ss) = do 
-	modify (empty:)
-	mapM typeCheckStm ss
-	modify tail
-	return NoType
+	return ()
+typeCheckStm (SBlock ss) = pushAndPop $ mapM typeCheckStm ss
 typeCheckStm (SIf e s s') = do
 	TBool <- typeCheckExp e
-	NoType <- typeCheckStm s
-	NoType <- typeCheckStm s
-	return NoType
+	pushAndPop $ typeCheckStm s
+	pushAndPop $ typeCheckStm s'
 typeCheckStm (SWhile e s) = do
 	TBool <- typeCheckExp e
-	NoType <- typeCheckStm s
-	return NoType
+	pushAndPop $ typeCheckStm s
+typeCheckStm (SDeclD t i) = addVariable i t
 typeCheckStm (SDecl t i e) = do
 	t2 <- typeCheckExp e
-	if t == t2 || t2 == NoType then do
-		(m:ms) <- get
-		case insertLookupWithKey (\k a1 a2 -> a1) i t m of
-			(Nothing,m') -> put (m':ms)
-			_ -> fail $ "Duplicate variable declaration: "++show i
-		return NoType
-		else fail $ "Illegal to assign an expression of type "++show t2++" to variable "++show i++" of type "++show t
+	assert (t == t2) $ "Illegal to assign an expression of type "++show t2++" to variable "++show i++" of type "++show t
+	addVariable i t
 typeCheckStm (SPrint e) = do
 	typeCheckExp e
-	return NoType
+	return ()
+
+addVariable :: (MonadState State m) => Ident -> Type -> m ()
+addVariable i t = do
+	s <- get
+	let (m:ms) = variables s in case insertLookupWithKey (\k a1 a2 -> a1) i t m of
+		(Nothing,m') -> modify (\s -> s{ variables = m':ms})
+		_ -> fail $ "Duplicate variable declaration: "++show i