(<++) :: Show a => Parser a -> Parser a -> Parser a
Parser p1 <++ Parser p2 = Parser $ \i l c -> case p1 i l c of Left _ -> p2 i l c
                                                              Right x -> Right x
(<++) :: Show a => Parser a -> Parser a -> Parser a
Parser p1 <++ Parser p2 = Parser $ \i l c -> case p1 i l c of Left _ -> p2 i l c
                                                              Right x -> Right x
Parser p1 <++ Parser p2 = Parser $ \i l c -> case p1 i l c of Left _ -> p2 i l c
                                                              Right x -> Right x