Data commit

Task/Bitwise-IO/Haskell/bitwise-io.hs

@@ -0,0 +1,30 @@
+import Data.List
+import Data.Char
+import Control.Monad
+import Control.Arrow
+import System.Environment
+
+int2bin :: Int -> [Int]
+int2bin = unfoldr(\x -> if x==0 then Nothing
+                          else Just (uncurry(flip(,)) (divMod x 2)))
+
+bin2int :: [Int] -> Int
+bin2int = foldr ((.(2 *)).(+)) 0
+
+bitReader = map (chr.bin2int). takeWhile(not.null). unfoldr(Just. splitAt 7)
+  . (take =<< (7 *) . (`div` 7) . length)
+
+bitWriter xs =  tt ++ z00 where
+  tt = concatMap (take 7.(++repeat 0).int2bin.ord) xs
+  z00 = replicate (length xs `mod` 8) 0
+
+main = do
+  (xs:_) <- getArgs
+  let bits = bitWriter xs
+
+  putStrLn "Text to compress:"
+  putStrLn $ '\t' : xs
+  putStrLn $ "Uncompressed text length is " ++ show (length xs)
+  putStrLn $ "Compressed text has " ++ show (length bits `div` 8) ++ " bytes."
+  putStrLn "Read and decompress:"
+  putStrLn $ '\t' : bitReader bits