module Typecheck where
import Abssyntax
+import Control.Monad.State
+import Data.Map as Map
+import Prelude hiding (lookup)
-typeCheckExp :: Exp -> Maybe Type
-BExp e o e' = do
- TInt <- typeCheck e
- TInt <- typeCheck e'
+
+type Types = Map Ident Type
+
+typeCheckExp :: (MonadState Types m) => Exp -> m Type
+typeCheckExp (BExp e o e') = do
+ TInt <- typeCheckExp e
+ TInt <- typeCheckExp e'
return TBool
-OpExp e o e' = do
- TInt <- typeCheck e
- TInt <- typeCheck e'
+typeCheckExp (OpExp e o e') = do
+ TInt <- typeCheckExp e
+ TInt <- typeCheckExp e'
return TInt
+typeCheckExp (EVar i) = typeCheckVar i
+typeCheckExp (EAss i e) = do
+ a <- typeCheckVar i
+ b <- typeCheckExp e
+ if a == b then return a else fail "FEL!"
+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 "FEL!"
+typeCheckExp EDefault = return NoType
+typeCheckExp (EPost i op) = do
+ TInt <- typeCheckVar i
+ return TInt
+
-typeCheckStm :: Stm -> Maybe Type
-SNoop = return NoType
-SExp e = typeCheckExp e
-SBlock ss = do
+typeCheckVar :: (MonadState Types m) => Ident -> m Type
+typeCheckVar i = do
+ e <- get
+ lookup i e
+
+typeCheckStm :: (MonadState Types m) => Stm -> m Type
+typeCheckStm SNoop = return NoType
+typeCheckStm (SExp e) = do
+ typeCheckExp e
+ return NoType
+typeCheckStm (SBlock ss) = do
mapM typeCheckStm ss
return NoType
-SIf e s s' = do
+typeCheckStm (SIf e s s') = do
TBool <- typeCheckExp e
NoType <- typeCheckStm s
NoType <- typeCheckStm s
return NoType
-SWhile e s = do
+typeCheckStm (SWhile e s) = do
TBool <- typeCheckExp e
NoType <- typeCheckStm s
+ return NoType
+typeCheckStm (SDecl t i e) = do
+ t2 <- typeCheckExp e
+ if t == t2 then do
+ m <- get
+ put (insert i t m)
+ return NoType
+ else fail "Så får du inte göra!!!"
+typeCheckStm (SPrint e) = do
+ typeCheckExp e
+ return NoType