From: Ramakrishnan Muthukrishnan <ram@rkrishnan.org>
Date: Sun, 17 May 2015 07:52:12 +0000 (+0530)
Subject: rewrite bitfieldToList
X-Git-Url: https://git.rkrishnan.org/listings/vdrive/rgr-080307.php?a=commitdiff_plain;h=d966c772fd0047528f6cc7110955ff4d8be89fbd;p=functorrent.git

rewrite bitfieldToList
---

diff --git a/src/FuncTorrent/Peer.hs b/src/FuncTorrent/Peer.hs
index 93e4a15..481f5da 100644
--- a/src/FuncTorrent/Peer.hs
+++ b/src/FuncTorrent/Peer.hs
@@ -145,19 +145,20 @@ getMsg h = do
     msg <- hGet h l
     return $ decode $ fromStrict $ concat [lBS, msg]
 
+
 bsToInt :: ByteString -> Int
 bsToInt x = fromIntegral (runGet getWord32be (fromChunks (return x)))
 
-bitfieldToList :: [Word8] -> Integer -> [Integer]
-bitfieldToList [] pos = []
-bitfieldToList (b:bs) pos =
-  let setBits = [pos*8 + (toInteger i) | i <- [0..8], testBit b i]
-  in
-   setBits ++ (bitfieldToList bs (pos + 1))
+bitfieldToList :: [Word8] -> [Integer]
+bitfieldToList bs = go bs 0
+  where go [] _ = []
+        go (b:bs') pos =
+          let setBits = [pos*8 + (toInteger i) | i <- [0..8], testBit b i]
+          in
+           setBits ++ (go bs' (pos + 1))
 
 -- loop1 :: shake hands with all peers, find out the pieces they have, form PieceData.
 -- recvMsg :: Peer -> Handle -> Msg
-
 msgLoop :: Handle -> ByteString -> IO ()
 msgLoop h pieceHash =
   let numPieces = (toInteger . (`quot` 20) . BC.length) pieceHash