More laziness.

1 files changed, 9 insertions, 4 deletions

diff --git a/Data/Digest/CRC24.hs b/Data/Digest/CRC24.hs
index 4637834..4586177 100644
--- a/Data/Digest/CRC24.hs
+++ b/Data/Digest/CRC24.hs
@@ -4,12 +4,14 @@
 -- (See the LICENSE file).
 
 module Data.Digest.CRC24 (
-  crc24
+   crc24
+ , crc24Lazy
 ) where
 
 import Data.Bits (shiftL, (.&.), xor)
-import Data.ByteString (ByteString)
+import Data.ByteString.Lazy (ByteString)
 import qualified Data.ByteString as B
+import qualified Data.ByteString.Lazy as BL
 import Data.Word (Word8, Word32)
 
 crc24_init :: Word32
@@ -21,5 +23,8 @@ crc24_poly = 0x1864CFB
 crc24_update :: Word32 -> Word8 -> Word32
 crc24_update c b = (last . take 9 $ iterate (\x -> if (shiftL x 1) .&. 0x1000000 == 0x1000000 then shiftL x 1 `xor` crc24_poly else shiftL x 1) (c `xor` shiftL (fromIntegral b) 16)) .&. 0xFFFFFF
 
-crc24 :: ByteString -> Word32
-crc24 bs = B.foldl crc24_update crc24_init bs
+crc24 :: B.ByteString -> Word32
+crc24 bs = crc24Lazy . BL.fromChunks $ [bs]
+
+crc24Lazy :: ByteString -> Word32
+crc24Lazy bs = BL.foldl crc24_update crc24_init bs