-module Typecheck where -- (typeCheckExp, typeCheckStm, typeCheckVar, State) where
+module Typecheck (typeCheck, typeCheckExp, typeCheckStm, typeCheckVar, typeCheckFunction, addFunction, emptyState, 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
-inList _ [] = False
-inList a (x:xs) = if a == x then True else inList a xs
+emptyState = State{variables=[empty], functions=(empty), function=(Ident "")}
assert :: Monad m => Bool -> String -> m ()
assert True _ = return ()
assert False s = fail s
+typeCheck :: [Func] -> [Stm] -> IO ()
+typeCheck fun st = do
+ runStateT (do mapM addFunction fun; mapM typeCheckFunction fun; mapM typeCheckStm st) emptyState
+ return ()
+
typeCheckExp :: (MonadState State m) => Exp -> m Type
typeCheckExp (BiOpExp e o e') = do
t1 <- typeCheckExp e
t2 <- typeCheckExp e'
assert (t1 == t2) "The parameters for the binary operator aren't equal"
- if inList o [Eq,NEq] then return TBool
+ if elem o [Eq,NEq] then return TBool
else do
assert (t1 == TInt) "The parameters need to be of type int"
- if inList o [Plus,Minus,Times,Div]
+ if elem o [Plus,Minus,Times,Div]
then return TInt
else return TBool
typeCheckExp (EVar i) = typeCheckVar i
typeCheckExp (ENot e) = do
TBool <- typeCheckExp e
return TBool
+typeCheckExp (EFunc i as) = do
+ state <- get
+ (t,ts) <- lookup i $ functions state
+ checkParams as ts
+ return t
+
+checkParams :: (MonadState State m) => [Exp] -> [Type] -> m ()
+checkParams [] [] = return ()
+checkParams [] _ = fail "Too for arguments when calling function"
+checkParams _ [] = fail "Too many arguments when calling function"
+checkParams (e:es) (t:ts) = do
+ t2 <- typeCheckExp e
+ assert (t == t2) "Arugments does not match"
+ checkParams es ts
typeCheckVar :: (MonadState State m) => Ident -> m Type
typeCheckVar i = do
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
+ case last s of
+ (SReturn _) -> return ()
+ _ -> fail $ "Function "++show i++" doesn't end with return statement"
+ 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