March 2014 update

Task/CRC-32/Haskell/crc-32-1.hs

@@ -0,0 +1,21 @@
+import Data.Bits
+import Data.Word
+import Numeric
+
+crcTable :: Word32 -> Word32
+crcTable i = table !! (fromIntegral i)
+        where
+                table = map (\a -> iterate xf a !! 8) [0..255]
+                xf r = let d = shiftR r 1 in
+                        if r .&. 1 == 1 then xor d 0xedb88320 else d
+
+charToWord :: Char -> Word32
+charToWord c = (fromIntegral . fromEnum) c
+
+calcCrc :: String -> Word32
+calcCrc text = complement ( foldl cf (complement 0) text )
+        where cf crc x = xor (shiftR crc 8) (crcTable $ xor (crc .&. 0xff) (charToWord x) )
+
+crc32 text = showHex ( calcCrc text ) ""
+
+main = putStrLn $ crc32 "The quick brown fox jumps over the lazy dog"

Task/CRC-32/Haskell/crc-32-2.hs

@@ -0,0 +1,13 @@
+import Data.List (genericLength)
+import Numeric (showHex)
+import Foreign.C
+
+foreign import ccall "zlib.h crc32" zlib_crc32 :: CULong -> CString -> CUInt -> CULong
+
+main = do
+        let s = "The quick brown fox jumps over the lazy dog"
+        ptr <- newCString s
+
+        let r = zlib_crc32 0 ptr (genericLength s)
+
+        putStrLn $ showHex r ""