-module Typecheck where -- (typeCheckExp, typeCheckStm, typeCheckVar, State) where
+module Typecheck (typeCheckExp, typeCheckStm, typeCheckVar, typeCheckFunction, addFunction, State(..)) where
import Abssyntax
import Control.Monad.State hiding (State)
-import Data.Map as Map
+import Data.Map as Map hiding (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}
+data State = State {variables::Types,functions::(Map Ident Function),function::Ident}
inList :: Eq a => a -> [a] -> Bool
typeCheckStm (SPrint e) = do
typeCheckExp e
return ()
+typeCheckStm (SReturn e) = do
+ t <- typeCheckExp e
+ state <- get
+ (t2,_) <- lookup (function state) $ functions state
+ assert (t == t2) $ "Illegal to return "++show t++" in function "++show (function state)++" which returns "++show t2
+
addVariable :: (MonadState State m) => Ident -> Type -> m ()
addVariable i t = do
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
+
+typeCheckFunction :: (MonadState State m) => Func -> m ()
+typeCheckFunction (Func t i d s) = do
+ state <- get
+ modify (\s -> s{variables=[empty], function=i})
+ mapM (\(Decl t i) -> addVariable i t) d
+ mapM typeCheckStm s
+ put state
+
+addFunction :: (MonadState State m) => Func -> m ()
+addFunction (Func t i d _) = do
+ s <- get
+ let m = functions s in case insertLookupWithKey (\k a1 a2 -> a1) i (t, map (\(Decl t i) -> t) d) m of
+ (Nothing,m') -> modify (\s -> s{ functions = m'})
+ _ -> fail $ "Duplicate variable declaration: "++show i
Ok (Program s) -> let (fun,st) = splitFunStm (s) in do
putStrLn "\nParse Successful!"
showTree v (Program s)
- runStateT (mapM typeCheckStm st) State{variables=[empty], functions=[empty], function=(Ident "")}
+ runStateT (do mapM addFunction fun; mapM typeCheckFunction fun; mapM typeCheckStm st) State{variables=[empty], functions=(empty), function=(Ident "")}
print "The program is type-correct!!"
return ()