X-Git-Url: https://ruin.nu/git/?a=blobdiff_plain;f=Interpret.hs;h=0728d5181c967cf6d109f3327f2d8905e6738b1e;hb=cfe5796efb06251047f77bf9d2295d7093910292;hp=f1c820682806950a7912115488eb40be0f5fa4fc;hpb=2316d61f350f8b39c9a3f76b91d1d14796d5183b;p=proglang.git

diff --git a/Interpret.hs b/Interpret.hs
index f1c8206..0728d51 100644
--- a/Interpret.hs
+++ b/Interpret.hs
@@ -1,4 +1,4 @@
-module Interpret (eval, execute, Value(VInt, VBool)) where
+module Interpret (interpret, eval, execute, Value(VInt, VBool)) where
 
 import Abssyntax
 import Control.Monad.State
@@ -9,75 +9,110 @@ data Value = VInt Integer | VBool Bool deriving Eq
 
 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]
 
-inList :: Eq a => a -> [a] -> Bool
-inList _ [] = False
-inList a (x:xs) = if a == x then True else inList a xs
+interpret :: [Stm] -> IO ()
+interpret s = runStateT (mapM execute s) [empty] >> return ()
 
 --eval :: (MonadState Variables m) => Exp -> m Value
 eval :: Exp -> StateT Variables IO 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 EDefault = return (VInt 0) --FIXME!!!
+eval (EAss i e) = setVariableValue i e
 eval (BiOpExp e o e') = do
 	v <- eval e
 	v'<- eval e'
-	if inList o [Eq,NEq] then return $ opE o v v'
+	if elem o [Eq,NEq] then return $ opE o v v'
 		else let (VInt n1) = v in let (VInt n2) = v' in return $ op o n1 n2
-typeCheckExp (EPost i op) = do
+eval (EPost i o) = do
 	(VInt n) <- getVariableValue i
-	setVariableValue i $ EInt $ n+1
+	let (VInt n') = op o n 1 in setVariableValue i $ EInt n'
 	return $ VInt n
+eval (ENeg e) = do
+	(VInt n) <- eval e
+	return $ VInt $ -n
+eval (ENot e) = do
+	(VBool b) <- eval e
+	return $ VBool $ not b
+eval EReadI = do
+	s <- lift $ getWord
+	return $ VInt $ read s
+eval EReadB = do
+	s <- lift $ getWord
+	return $ VBool $ if (read s == 0) then False else True
+
+getWord :: IO String
+getWord =  do
+	c <- getChar
+	if elem c [' ', '\n', '\t', '\r']
+		then return ""
+		else do
+			l <- getWord
+			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'
+op EGt = \e e' -> VBool $ e >= e'
 
 getVariableValue :: (MonadState Variables m) => Ident -> m Value 
 getVariableValue i = do
 	ms <- get 
 	findVariable i ms
 
+findVariable :: (MonadState  Variables m) => Ident -> Variables -> m Value
+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
+
 --setVariableValue :: (MonadState Variables m) => Ident -> Exp -> m Value 
+--setVariableValue :: (MonadState Variables m) => Ident -> Exp -> m Value 
+
 setVariableValue :: Ident -> Exp -> StateT Variables IO Value
 setVariableValue i e = do
-	e' <- eval e
-	(m:ms) <- get
-	put $ (insert i e' m):ms
-	return e'
+	v <- eval e
+	ms <- get
+	put $ updateVariable i v ms
+	return v
 
-findVariable :: (MonadState  Variables m) => Ident -> Variables -> m Value
-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
+updateVariable :: Ident -> Value -> Variables -> Variables 
+updateVariable _ _ [] = []
+updateVariable i v (m:ms) = if member i m then insert i v m:ms else m:updateVariable i v ms
+
+pushAndPop :: (MonadState Variables m) => m a -> m ()
+pushAndPop s = do
+	modify (empty:)
+	s
+	modify tail
 
 -- execute :: (MonadState Variables m) => Stm -> m ()
 execute :: Stm -> StateT Variables IO ()
+execute (SNoop) = return ()
+execute (SExp e) = eval e >> return ()
 execute (SIf b s s') = do
 	(VBool b') <- eval b
-	if b' then execute s else execute s'
+	pushAndPop $ if b' then execute s else execute s'
 execute (SPrint e) = do
 	e' <- eval e
 	lift $ print e'
-execute (SNoop) = return ()
-execute (SBlock ss) = do
-	modify (empty:)
-	mapM execute ss
-	modify tail
+execute (SBlock ss) = pushAndPop $ mapM execute ss
 execute (SWhile e s) = do
 	(VBool b) <- eval e
-	if b then execute (SWhile e s) else return ()
-execute (SDecl t i EDefault) = do
-	case t of
-		TInt -> setVariableValue i (EInt 0)
-		TBool -> setVariableValue i (EBool False)
-	return ()
-execute (SDecl t i e) = setVariableValue i e >> return ()
+	if b then pushAndPop (execute s) >> execute (SWhile e s) else return ()
+execute (SDeclD t i) = execute $ SDecl t i $ case t of
+	TInt -> EInt 0
+	TBool -> EBool False
+execute (SDecl t i e) =do
+	v <- eval e
+	(m:ms) <- get
+	put $ (insert i v m):ms