Changeset 26 for sizechecking/branches/macs/Lambda.hs

Timestamp:

May 4, 2014, 8:06:39 PM (11 years ago)

Author:

gobi

Message:

lambda

File:

• sizechecking/branches/macs/Lambda.hs (modified) (3 diffs)

sizechecking/branches/macs/Lambda.hs

@@ -1 @@
-{-# LANGUAGE TypeFamilies #-}
+{-# LANGUAGE TypeFamilies, GADTs #-}
 
 module Lambda where
@@ -36 +36 @@
     else showChar $ C.chr $ C.ord 'a' + x
 
--- unS :: Value supply -> Precedence -> ShowS
 newtype S a = S { unS :: S.Supply Int -> Int -> ShowS }
 
@@ -59 +58 @@
 
 
-type family Sem (m :: * -> *) a :: *
-type instance Sem m Int      = Int
-type instance Sem m (a -> b) = m (Sem m a) -> m (Sem m b)
+{-
+ - reduction
+ -}
+data IR h t where
+    Lit :: Int -> IR h Int
+    App :: IR h (a -> b) -> IR h a -> IR h b
+    Lam :: (IR h a -> IR h b) -> IR h (a -> b)
 
-newtype R m a = R { unR :: m (Sem m a) }
+instance Lambda (IR h) where
+    lam = Lam
+    app = App
+    lit = Lit
 
-share :: (MonadIO m) => m a -> m (m a)
-share f = do
-    mem <- liftIO $ newIORef (False, f)
-    return $ do
-        (evald, thunk) <- liftIO $ readIORef mem
-        if evald then thunk
-        else do
-          value <- thunk
-          liftIO $ writeIORef mem (True, return value)
-          return value
-
-instance (MonadIO m) => Lambda (R m) where 
-    app x y = R $ unR x >>= ($ (unR y))
-    lit = R . return
-    lam f   = R . return $ (\x -> share x >>= unR . f . R)
+toFinal :: (Lambda l) => IR h t