instance Show Value where
show (VInt n) = show n
- show (VBool b) = show b
+ show (VBool True) = "1"
+ show (VBool False) = "0"
type Variables = [Map Ident Value]
eval (EBool b) = return (VBool b)
eval (EInt n) = return (VInt n)
eval (EVar i) = getVariableValue i
-eval (EAss i e) = setVariableValue i e
+eval (EAss i e) = setVariableValue i e
eval (BiOpExp e o e') = do
v <- eval e
v'<- eval e'
return $ VInt $ read s
eval EReadB = do
s <- lift $ getWord
- return $ VBool $ read s
+ return $ VBool $ if (read s == 0) then False else True
getWord :: IO String
getWord = do
c <- getChar
- if inList c ['\n','\r',' ', '\t']
+ if inList c [' ', '\n', '\t', '\r']
then return ""
else do
l <- getWord
- return (c:l)
+ return (c:l)
-- op :: Op -> (a -> a -> Value)
opE Eq = \e e' -> VBool $ e == e'
opE NEq = \e e' -> VBool $ not (e == e')
op Plus = \e e' -> VInt $ e + e'
-op Minus = \e e' -> VInt $ e - e'
-op Times = \e e' -> VInt $ e * e'
-op Div = \e e' -> VInt $ e `div` e'
+op Minus = \e e' -> VInt $ e - e'
+op Times = \e e' -> VInt $ e * e'
+op Div = \e e' -> VInt $ e `div` e'
op Lt = \e e' -> VBool $ e < e'
op ELt = \e e' -> VBool $ e <= e'
op Gt = \e e' -> VBool $ e > e'
execute (SWhile e s) = do
(VBool b) <- eval e
if b then pushAndPop (execute s) >> execute (SWhile e s) else return ()
-execute (SDeclD t i) = execute (SDecl t i $ case t of
+execute (SDeclD t i) = execute $ SDecl t i $ case t of
TInt -> EInt 0
TBool -> EBool False
- )
execute (SDecl t i e) =do
- e' <- eval e
+ v <- eval e
(m:ms) <- get
- put $ (insert i e' m):ms
+ put $ (insert i v m):ms