parser battle

gistfile1.hs

data Passport = Passport Word8 Word32

parsePassport :: Parser (Either ByteString Passport)
parsePassport = good <|> bad
    where
        bad = Left <$> takeWhile (/= '\n') <* endOfLine

        good = Right <$> (Passport <$> label <*> body <* endOfLine)
          where
            label = fromIntegral . digitToInt <$> digit
            body = do
                x <- decimal <* char ','
                y <- decimal
                return $ x * 1000000 + y