//  Begin grammar

           (
                    -(*(char_ - lit("://")) >> lit("://")) >>
                    (
                            // : means we are going to append a port number. / is the beginning of the path
                            +(char_ - ':' - '/') >>

                            //Port number - optional
                            -(':' >> int_) >>

                            //path
                            -('/' >> +(char_))

                    )
        ),