Index: /sizechecking/branches/macs/Lambda.hs
===================================================================
--- /sizechecking/branches/macs/Lambda.hs	(revision 19)
+++ /sizechecking/branches/macs/Lambda.hs	(revision 19)
@@ -0,0 +1,58 @@
+{-# LANGUAGE FlexibleContexts,FlexibleInstances #-}
+module Lambda where
+
+import qualified Data.Supply as S
+import qualified Data.Char as C
+
+{-
+ - Lambda calculus beagyazas
+ -}
+class Lambda l where
+    lam   :: (l a -> l b) -> l (a -> b)
+    app   :: l (a -> b) -> l a -> l b
+    const :: Int -> l Int
+
+
+{-
+ - eval interpreter
+ -}
+newtype Q a = Q { unQ :: a }
+instance Lambda Q where
+    const = Q
+    lam a = Q (unQ.a.Q)
+    app a b = Q $ (unQ a) (unQ b)
+
+eval = unQ
+
+instance Num a => Num (Q a) where
+    (Q a) + (Q b) = Q (a+b)
+    (Q a) - (Q b) = Q (a-b)
+    (Q a) * (Q b) = Q (a*b)
+    abs (Q a) = Q (abs a)
+
+
+{-
+ - show interpreter
+ -}
+showVar x = if x>28 
+    then showVar (x `div` 29) . showChar (C.chr $ C.ord 'a' + (x `mod` 29))
+    else showChar $ C.chr $ C.ord 'a' + x
+
+newtype S a = S { unS :: S.Supply Int -> Int -> ShowS }
+instance Lambda S where
+    const a = S (\s p -> flip showsPrec a p)
+    app (S fun) (S arg) = S (\s p -> 
+        let (s1, s2) = S.split2 s 
+        in showParen (p>6) $ fun s1 6 . showChar ' ' . arg s2 7)
+    lam fun = S (\s p -> 
+        let (s1, s2) = S.split2 s
+            v        = S.supplyValue s1
+            showV = S $ \_ _ -> showVar v
+        in showParen (p>0) $ showChar 'λ' . showVar v . showChar '.' . unS (fun showV) s2 0)
+
+ast a = do
+    s <- S.newSupply 0 (+1)
+    return $ unS a s 0
+
+printAst a = ast a >>= (\a -> putStrLn $ a "")
+
Index: /sizechecking/branches/macs/tests/LambdaTest.hs
===================================================================
--- /sizechecking/branches/macs/tests/LambdaTest.hs	(revision 19)
+++ /sizechecking/branches/macs/tests/LambdaTest.hs	(revision 19)
@@ -0,0 +1,6 @@
+{-# LANGUAGE NoMonomorphismRestriction #-}
+import Lambda
+import Prelude ( (+), ($), Int )
+
+test1 :: (Lambda l) => l Int
+test1 = app (lam $ \x ->  (const 3)) (const 2)