libs/spirit/classic/example/fundamental/matching_tags.cpp
/*=============================================================================
Copyright (c) 2002-2003 Joel de Guzman
http://spirit.sourceforge.net/
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)
=============================================================================*/
////////////////////////////////////////////////////////////////////////////
//
// HTML/XML like tag matching grammar
// Demonstrates phoenix and closures and parametric parsers
// This is discussed in the "Closures" chapter in the Spirit User's Guide.
//
// [ JDG 6/30/2002 ]
//
////////////////////////////////////////////////////////////////////////////
#include <boost/spirit/include/classic_core.hpp>
#include <boost/spirit/include/classic_attribute.hpp>
#include <iostream>
#include <string>
////////////////////////////////////////////////////////////////////////////
using namespace std;
using namespace BOOST_SPIRIT_CLASSIC_NS;
using namespace phoenix;
////////////////////////////////////////////////////////////////////////////
//
// HTML/XML like tag matching grammar
//
////////////////////////////////////////////////////////////////////////////
struct tags_closure : BOOST_SPIRIT_CLASSIC_NS::closure<tags_closure, string>
{
member1 tag;
};
struct tags : public grammar<tags>
{
template <typename ScannerT>
struct definition {
definition(tags const& /*self*/)
{
element = start_tag >> *element >> end_tag;
start_tag =
'<'
>> lexeme_d
[
(+alpha_p)
[
// construct string from arg1 and arg2 lazily
// and assign to element.tag
element.tag = construct_<string>(arg1, arg2)
]
]
>> '>';
end_tag = "</" >> f_str_p(element.tag) >> '>';
}
rule<ScannerT, tags_closure::context_t> element;
rule<ScannerT> start_tag, end_tag;
rule<ScannerT, tags_closure::context_t> const&
start() const { return element; }
};
};
////////////////////////////////////////////////////////////////////////////
//
// Main program
//
////////////////////////////////////////////////////////////////////////////
int
main()
{
cout << "/////////////////////////////////////////////////////////\n\n";
cout << "\t\tHTML/XML like tag matching parser demo \n\n";
cout << "/////////////////////////////////////////////////////////\n\n";
cout << "Type an HTML/XML like nested tag input...or [q or Q] to quit\n\n";
cout << "Example: <html><head></head><body></body></html>\n\n";
tags p; // Our parser
string str;
while (getline(cin, str))
{
if (str.empty() || str[0] == 'q' || str[0] == 'Q')
break;
parse_info<> info = parse(str.c_str(), p, space_p);
if (info.full)
{
cout << "-------------------------\n";
cout << "Parsing succeeded\n";
cout << "-------------------------\n";
}
else
{
cout << "-------------------------\n";
cout << "Parsing failed\n";
cout << "stopped at: \": " << info.stop << "\"\n";
cout << "-------------------------\n";
}
}
cout << "Bye... :-) \n\n";
return 0;
}