Data commit

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

@@ -0,0 +1,26 @@
+import Data.Bits ((.&.), complement, shiftR, xor)
+import Data.Word (Word32)
+import Numeric (showHex)
+
+crcTable :: Word32 -> Word32
+crcTable = (table !!) . fromIntegral
+  where
+    table = ((!! 8) . iterate xf) <$> [0 .. 255]
+    shifted x = shiftR x 1
+    xf r
+      | r .&. 1 == 1 = xor (shifted r) 0xedb88320
+      | otherwise = shifted r
+
+charToWord :: Char -> Word32
+charToWord = fromIntegral . fromEnum
+
+calcCrc :: String -> Word32
+calcCrc = complement . foldl cf (complement 0)
+  where
+    cf crc x = xor (shiftR crc 8) (crcTable $ xor (crc .&. 0xff) (charToWord x))
+
+crc32 :: String -> String
+crc32 = flip showHex [] . calcCrc
+
+main :: IO ()
+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 :: IO ()
+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 ""