X-Git-Url: https://ruin.nu/git/?a=blobdiff_plain;f=Interpret.hs;h=948903ebd9416e6de394f62cc4c27772eacd96b0;hb=e4867d1f76874882921ec9501d20834a4d96eb5a;hp=8cf3c1b2657270d016c8f28256b993adbd566c96;hpb=3e277a6a62728085cd8ba735b50bdac0b6d68808;p=proglang.git

diff --git a/Interpret.hs b/Interpret.hs
index 8cf3c1b..948903e 100644
--- a/Interpret.hs
+++ b/Interpret.hs
@@ -1,10 +1,14 @@
-module Interpret (eval, execute, Value(VInt, VBool)) where
+module Interpret (interpret, eval, execute,addFunction, emptyState, Value(..), State(..)) where
 
 import Abssyntax
-import Control.Monad.State
+import Control.Monad.State hiding (State)
+import Control.Monad.Error
+import Control.Concurrent.MVar
 import Data.Map as Map
 import Prelude hiding (lookup)
 
+emptyState = State{variables=[empty], functions=(empty), ret=(VInt 0)}
+
 data Value = VInt Integer | VBool Bool deriving Eq
 
 instance Show Value where
@@ -13,13 +17,19 @@ instance Show Value where
 	show (VBool False) = "0"
 
 type Variables = [Map Ident Value]
+type Function = ([Decl],[Stm])
+
+data State = State {variables::Variables,functions::(Map Ident Function),ret::Value}
+
+type EvalM = ErrorT String (StateT State IO)
 
-inList :: Eq a => a -> [a] -> Bool
-inList _ [] = False
-inList a (x:xs) = if a == x then True else inList a xs
+interpret :: [Func] -> [Stm] -> IO ()
+interpret fun st = do
+	runStateT (runErrorT  (do mapM Interpret.addFunction fun; mapM_ execute st)) emptyState
+	return ()
 
 --eval :: (MonadState Variables m) => Exp -> m Value
-eval :: Exp -> StateT Variables IO Value
+eval :: Exp -> EvalM Value
 eval (EBool b) = return (VBool b)
 eval (EInt n) = return (VInt n)
 eval (EVar i) = getVariableValue i
@@ -27,7 +37,7 @@ 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
 eval (EPost i o) = do
 	(VInt n) <- getVariableValue i
@@ -40,16 +50,26 @@ eval (ENot e) = do
 	(VBool b) <- eval e
 	return $ VBool $ not b
 eval EReadI = do
-	s <- lift $ getWord
+	s <- liftIO $ getWord
 	return $ VInt $ read s
 eval EReadB = do
-	s <- lift $ getWord
+	s <- liftIO $ getWord
 	return $ VBool $ if (read s == 0) then False else True
+eval (EFunc i as) = do
+	vs <- mapM eval as
+	state <- get
+	(ds,ss) <- lookup i $ functions state
+	let m = foldr (\((Decl t i),v) m -> insert i v m) empty $ zip ds vs
+		in modify (\s -> s{variables=[m]})
+	mapM_ execute ss `catchError` (\_ -> return ())
+	s <- get
+	put state
+	return $ ret s
 
 getWord :: IO String
 getWord =  do
 	c <- getChar
-	if inList c [' ', '\n', '\t', '\r']
+	if elem c [' ', '\n', '\t', '\r']
 		then return ""
 		else do
 			l <- getWord
@@ -67,37 +87,34 @@ 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 :: (MonadState State m) => Ident -> m Value 
 getVariableValue i = do
-	ms <- get 
-	findVariable i ms
+	s <- get 
+	findVariable i $ variables s
 
-findVariable :: (MonadState  Variables m) => Ident -> Variables -> m Value
+findVariable :: (MonadState State 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 :: Ident -> Exp -> EvalM Value
 setVariableValue i e = do
 	v <- eval e
-	ms <- get
-	put $ updateVariable i v ms
+	state <- get
+	modify (\s -> s{variables= updateVariable i v $ variables state} )
 	return v
 
 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 :: (MonadState State m) => m a -> m ()
 pushAndPop s = do
-	modify (empty:)
+	modify (\s -> s { variables = empty:variables s})
 	s
-	modify tail
+	modify (\s -> s { variables = tail $ variables s})
 
 -- execute :: (MonadState Variables m) => Stm -> m ()
-execute :: Stm -> StateT Variables IO ()
+execute :: Stm -> EvalM ()
 execute (SNoop) = return ()
 execute (SExp e) = eval e >> return ()
 execute (SIf b s s') = do
@@ -105,7 +122,7 @@ execute (SIf b s s') = do
 	pushAndPop $ if b' then execute s else execute s'
 execute (SPrint e) = do
 	e' <- eval e
-	lift $ print e'
+	liftIO $ print e'
 execute (SBlock ss) = pushAndPop $ mapM execute ss
 execute (SWhile e s) = do
 	(VBool b) <- eval e
@@ -115,5 +132,12 @@ execute (SDeclD t i) = execute $ SDecl t i $ case t of
 	TBool -> EBool False
 execute (SDecl t i e) =do
 	v <- eval e
-	(m:ms) <- get
-	put $ (insert i v m):ms
+	state <- get
+	let (m:ms) = variables state in modify (\s -> s{variables=insert i v m:ms })
+execute (SReturn e) = do
+	v <- eval e
+	modify (\s -> s{ret=v})
+	throwError "Returning.."
+
+addFunction :: (MonadState State m) => Func -> m ()
+addFunction (Func _ i d ss) = modify (\s -> s{functions=insert i (d,ss) (functions s) })