Parse an IP address with attoparsec

ip.hs

{-# LANGUAGE OverloadedStrings #-}
import Control.Applicative
import Data.Attoparsec.Text
import Data.Word

data IP = IP Word8 Word8 Word8 Word8 deriving (Eq, Show)

parseIP :: Parser IP
parseIP = IP <$> dec <*> dec <*> dec <*> decimal <?> "parse IP Address"
  where dot = char '.'
        dec = decimal <* dot

main :: IO ()
main = print $ parseOnly parseIP "1.2.3.4"