haskell StrConverter

StrConverter.hs

import Data.Char (ord, chr)

type Bit = Int

bin2int :: [Bit] -> Int
bin2int bits = sum [w * b | (w, b) <- zip weights bits]
               where weights = iterate (* 2) 1

int2bin :: Int -> [Bit]
int2bin 0 = []
int2bin n = r : int2bin q
            where (q, r) = quotRem n 2

make8 :: [Bit] -> [Bit]
make8 bits = take 8 (bits ++ repeat 0)

encode :: String -> [Bit]
encode = concat . map (make8 . int2bin . ord)

chop8 :: [Bit] -> [[Bit]]
chop8 [] = []
chop8 bits = take 8 bits : (chop8 . drop 8 $ bits)

decode :: [Bit] -> String
decode = map (chr . bin2int) . chop8

channel :: [Bit] -> [Bit]
channel = id

transmit :: String -> String
transmit = decode . channel . encode