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/*=============================================================================
Copyright (c) 2001-2010 Joel de Guzman
Distributed under 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)
=============================================================================*/
///////////////////////////////////////////////////////////////////////////////
//
// A mini XML-like parser
//
// [ JDG March 25, 2007 ] spirit2
//
///////////////////////////////////////////////////////////////////////////////
#include <boost/config/warning_disable.hpp>
#include <boost/spirit/include/qi.hpp>
#include <boost/spirit/include/phoenix_core.hpp>
#include <boost/spirit/include/phoenix_operator.hpp>
#include <boost/spirit/include/phoenix_fusion.hpp>
#include <boost/spirit/include/phoenix_stl.hpp>
#include <boost/fusion/include/adapt_struct.hpp>
#include <boost/variant/recursive_variant.hpp>
#include <boost/foreach.hpp>
#include <iostream>
#include <fstream>
#include <string>
#include <vector>
namespace client
{
namespace fusion = boost::fusion;
namespace phoenix = boost::phoenix;
namespace qi = boost::spirit::qi;
namespace ascii = boost::spirit::ascii;
///////////////////////////////////////////////////////////////////////////
// Our mini XML tree representation
///////////////////////////////////////////////////////////////////////////
//[tutorial_xml1_structures
struct mini_xml;
typedef
boost::variant<
boost::recursive_wrapper<mini_xml>
, std::string
>
mini_xml_node;
struct mini_xml
{
std::string name; // tag name
std::vector<mini_xml_node> children; // children
};
//]
}
// We need to tell fusion about our mini_xml struct
// to make it a first-class fusion citizen
//[tutorial_xml1_adapt_structures
BOOST_FUSION_ADAPT_STRUCT(
client::mini_xml,
(std::string, name)
(std::vector<client::mini_xml_node>, children)
)
//]
namespace client
{
///////////////////////////////////////////////////////////////////////////
// Print out the mini xml tree
///////////////////////////////////////////////////////////////////////////
int const tabsize = 4;
void tab(int indent)
{
for (int i = 0; i < indent; ++i)
std::cout << ' ';
}
struct mini_xml_printer
{
mini_xml_printer(int indent = 0)
: indent(indent)
{
}
void operator()(mini_xml const& xml) const;
int indent;
};
struct mini_xml_node_printer : boost::static_visitor<>
{
mini_xml_node_printer(int indent = 0)
: indent(indent)
{
}
void operator()(mini_xml const& xml) const
{
mini_xml_printer(indent+tabsize)(xml);
}
void operator()(std::string const& text) const
{
tab(indent+tabsize);
std::cout << "text: \"" << text << '"' << std::endl;
}
int indent;
};
void mini_xml_printer::operator()(mini_xml const& xml) const
{
tab(indent);
std::cout << "tag: " << xml.name << std::endl;
tab(indent);
std::cout << '{' << std::endl;
BOOST_FOREACH(mini_xml_node const& node, xml.children)
{
boost::apply_visitor(mini_xml_node_printer(indent), node);
}
tab(indent);
std::cout << '}' << std::endl;
}
///////////////////////////////////////////////////////////////////////////
// Our mini XML grammar definition
///////////////////////////////////////////////////////////////////////////
//[tutorial_xml1_grammar
template <typename Iterator>
struct mini_xml_grammar : qi::grammar<Iterator, mini_xml(), ascii::space_type>
{
mini_xml_grammar() : mini_xml_grammar::base_type(xml)
{
using qi::lit;
using qi::lexeme;
using ascii::char_;
using ascii::string;
using namespace qi::labels;
using phoenix::at_c;
using phoenix::push_back;
text = lexeme[+(char_ - '<') [_val += _1]];
node = (xml | text) [_val = _1];
start_tag =
'<'
>> !lit('/')
>> lexeme[+(char_ - '>') [_val += _1]]
>> '>'
;
end_tag =
"</"
>> lit(_r1)
>> '>'
;
xml =
start_tag [at_c<0>(_val) = _1]
>> *node [push_back(at_c<1>(_val), _1)]
>> end_tag(at_c<0>(_val))
;
}
qi::rule<Iterator, mini_xml(), ascii::space_type> xml;
qi::rule<Iterator, mini_xml_node(), ascii::space_type> node;
qi::rule<Iterator, std::string(), ascii::space_type> text;
qi::rule<Iterator, std::string(), ascii::space_type> start_tag;
qi::rule<Iterator, void(std::string), ascii::space_type> end_tag;
};
//]
}
///////////////////////////////////////////////////////////////////////////////
// Main program
///////////////////////////////////////////////////////////////////////////////
int main(int argc, char **argv)
{
char const* filename;
if (argc > 1)
{
filename = argv[1];
}
else
{
std::cerr << "Error: No input file provided." << std::endl;
return 1;
}
std::ifstream in(filename, std::ios_base::in);
if (!in)
{
std::cerr << "Error: Could not open input file: "
<< filename << std::endl;
return 1;
}
std::string storage; // We will read the contents here.
in.unsetf(std::ios::skipws); // No white space skipping!
std::copy(
std::istream_iterator<char>(in),
std::istream_iterator<char>(),
std::back_inserter(storage));
typedef client::mini_xml_grammar<std::string::const_iterator> mini_xml_grammar;
mini_xml_grammar xml; // Our grammar
client::mini_xml ast; // Our tree
using boost::spirit::ascii::space;
std::string::const_iterator iter = storage.begin();
std::string::const_iterator end = storage.end();
bool r = phrase_parse(iter, end, xml, space, ast);
if (r && iter == end)
{
std::cout << "-------------------------\n";
std::cout << "Parsing succeeded\n";
std::cout << "-------------------------\n";
client::mini_xml_printer printer;
printer(ast);
return 0;
}
else
{
std::string::const_iterator some = iter + std::min(30, int(end - iter));
std::string context(iter, (some>end)?end:some);
std::cout << "-------------------------\n";
std::cout << "Parsing failed\n";
std::cout << "stopped at: \"" << context << "...\"\n";
std::cout << "-------------------------\n";
return 1;
}
}
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