#ifndef BOOST_ARCHIVE_ITERATORS_XML_UNESCAPE_HPP

#define BOOST_ARCHIVE_ITERATORS_XML_UNESCAPE_HPP



// MS compatible compilers support #pragma once

#if defined(_MSC_VER) && (_MSC_VER >= 1020)

# pragma once

#endif



/////////1/////////2/////////3/////////4/////////5/////////6/////////7/////////8

// xml_unescape.hpp



// (C) Copyright 2002 Robert Ramey - http://www.rrsd.com . 

// Use, modification and distribution is subject to the Boost Software

// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at

// http://www.boost.org/LICENSE_1_0.txt)



//  See http://www.boost.org for updates, documentation, and revision history.



#include <cassert>



#include <boost/config.hpp> // for BOOST_DEDUCED_TYPENAME

#include <boost/throw_exception.hpp>

#include <boost/pfto.hpp>



#include <boost/archive/iterators/unescape.hpp>

#include <boost/archive/iterators/dataflow_exception.hpp>



namespace boost { 

namespace archive {

namespace iterators {



/////////1/////////2/////////3/////////4/////////5/////////6/////////7/////////8

// replace &??? xml escape sequences with the corresponding characters

template<class Base>

class xml_unescape 

    : public unescape<xml_unescape<Base>, Base>

{

    friend class boost::iterator_core_access;

    typedef xml_unescape<Base> this_t;

    typedef unescape<this_t, Base> super_t;

    typedef BOOST_DEDUCED_TYPENAME boost::iterator_reference<this_t> reference_type;



    reference_type dereference() const {

        return unescape<xml_unescape<Base>, Base>::dereference();

    }

public:

    void drain_residue(const char *literal);

    int drain();



    template<class T>

    xml_unescape(BOOST_PFTO_WRAPPER(T) start) : 

        super_t(Base(BOOST_MAKE_PFTO_WRAPPER(static_cast<T>(start))))

    {}

    // intel 7.1 doesn't like default copy constructor

    xml_unescape(const xml_unescape & rhs) : 

        super_t(rhs.base_reference())

    {}

};



template<class Base>

void xml_unescape<Base>::drain_residue(const char * literal){

    do{

        if(* literal != * ++(this->base_reference()))

            boost::throw_exception(

                dataflow_exception(

                    dataflow_exception::invalid_xml_escape_sequence

                )

            );

    }

    while('\0' != * ++literal);

}



// note key constraint on this function is that can't "look ahead" any

// more than necessary into base iterator.  Doing so would alter the base

// iterator refenence which would make subsequent iterator comparisons

// incorrect and thereby break the composiblity of iterators.

template<class Base>

int xml_unescape<Base>::drain(){

    int retval = * this->base_reference();

    if('&' != retval){

        return retval;

    }

    retval = * ++(this->base_reference());

    switch(retval){

    case 'l': // &lt;

        drain_residue("t;");

        retval = '<';

        break;

    case 'g': // &gt;

        drain_residue("t;");

        retval = '>';

        break;

    case 'a':

        retval = * ++(this->base_reference());

        switch(retval){

        case 'p': // &apos;

            drain_residue("os;");

            retval = '\'';

            break;

        case 'm': // &amp;

            drain_residue("p;");

            retval = '&';

            break;

        }

        break;

    case 'q':

        drain_residue("uot;");

        retval = '"';

        break;

    }

    return retval;

}



} // namespace iterators

} // namespace archive

} // namespace boost



#endif // BOOST_ARCHIVE_ITERATORS_XML_UNESCAPE_HPP

