gistfile1.diff

--- twobit.hs.orig	2012-07-05 00:24:21.399187088 +0200
+++ twobit.hs	2012-07-05 00:38:06.288433147 +0200
@@ -1,3 +1,4 @@
+{-# LANGUAGE OverloadedStrings #-}
 import System.IO
 import Data.Char
 import System.Environment
@@ -9,7 +10,7 @@
          deriving (Show)
 data V = Fun (V -> V)
        | Val Int
-       | Str String
+       | Str LBC.ByteString
 
 app :: V -> V -> V
 app (Fun f) v = f v
@@ -26,21 +27,27 @@
 church i = Fun (\f -> Fun (\x -> iterate (app f) x !! i))
 
 -- \l . l (\a b i.unchurch a : unlist b) ""
-unlist :: V -> String
+unlist :: V -> LBC.ByteString
 unlist l = s where Str s = unlist' l
 unlist' :: V -> V
 unlist' l = l `app` Fun walk `app` Str "" where
-	walk a = Fun (\b -> Fun (\i-> Str (chr (unchurch a) : unlist b)))
+	walk a = Fun (\b -> Fun (\i-> Str (chr (unchurch a) `LBC.cons` unlist b)))
 
 cons a b = Fun (\x -> x `app` a `app` b)
 nil = Fun (\a -> Fun (\b -> b) )
-tolist "" = nil
-tolist (x:xs) = cons (church (ord x)) (tolist xs)
+tolist xs = 
+  case LBC.uncons xs of
+       Just (x, xs') ->
+         church (ord x) `cons` tolist xs'
+       Nothing ->
+         nil
 
-type BitStream = ([Int], String)
+type BitStream = ([Int], LBC.ByteString)
 stepBit :: BitStream -> (Int, BitStream)
 stepBit (x:xs, ys) = (x, (xs, ys))
-stepBit ([], y:ys) = ((ord y) `div` 128, (map (\p->(ord y) `div` 2^p `mod` 2) [6,5..0], ys))
+stepBit ([], ys) =
+  let Just (y, ys') = LBC.uncons ys
+  in ((ord y) `div` 128, (map (\p->(ord y) `div` 2^p `mod` 2) [6,5..0], ys'))
 
 parse :: BitStream -> (T, BitStream)
 parse s =
@@ -66,8 +73,8 @@
 main=do
 	sources <- mapM LBC.readFile =<< getArgs
 	hSetBuffering stdout NoBuffering
-	interact (\input->
+	LBC.interact (\input->
 		let
 			(tree, (_, rest)) = parse stream
-			stream = ([], concat sources ++ input)
+			stream = ([], LBC.concat sources `LBC.append` input)
 		in unlist (eval tree [] `app` tolist rest))
\ No newline at end of file