IoBind, a serializer code factory.

#include <string>
#include <strstream>
#include <boost/spirit.hpp> 
#include <iobind/xml_escape_policy.hpp>
#include <iobind/parser_utils.hpp>

namespace iobind{
namespace details{

const chset_p escapes_reserved_p("$&+'/:;=?@");
struct unescapes_reserved : boost::spirit::symbols<char>
{
    unescapes_reserved()
    {
        add
            ("36"    , '$')
            ("38"    , '&')
            ("43"    , '+')
            ("44"    , '\'')
            ("57"    , '/')
			("48"    , ':')
            ("59"    , ';')
            ("61"    , '=')
            ("63"    , '?')
            ("64"    , '@')
        ;
    }
} unescapes_reserved_p;

const chset_p escapes_unsafe_p(" \"<>#%{}|\\^~[]`");
struct unescapes_unsafe : boost::spirit::symbols<char>
{
    unescapes_unsafe()
    {
        add
            ("36"    , ' ')
            ("38"    , '\"')
            ("43"    , '<')
            ("44"    , '>')
			("57"    , '#')
			("48"    , '%')
			("59"    , '{')
			("61"    , '}')
            ("63"    , '|')
            ("64"    , '\\')
            ("64"    , '^')
            ("64"    , '~')
            ("64"    , '[')
            ("64"    , ']')
            ("64"    , '`')
        ;
    }
} unescapes_unsafe_p;

struct unescape_from_url_grammar : boost::spirit::grammar<unescape_from_url_grammar>
{
	std::ostream& out;

	explicit unescape_from_url_grammar( std::ostream& out_)
		:out(out_){};

   template <typename ScannerT>
   struct definition
   {    
        definition(unescape_from_url_grammar const& self)  
		{
			using namespace boost::spirit;
			
			// the rest is ok
			encoded_string=
				*( 
					 unescapes_p[concat_symbol(self.out)]
				   | anychar_p[concat_string(self.out)]
				 );
		};

		boost::spirit::rule<ScannerT> encoded_string;
		boost::spirit::rule<ScannerT> const& start() const { return encoded_string; };
   };
};

struct escape_to_xml_grammar : boost::spirit::grammar<escape_to_xml_grammar>
{
	std::ostream& out;

	explicit escape_to_xml_grammar( std::ostream& out_)
		:out(out_){};
  
   template <typename ScannerT>
   struct definition
   {    
        definition(escape_to_xml_grammar const& self)  
		{
			using namespace boost::spirit;
			
			// the rest is ok
			encoded_string=
				*( 
					 escapes_p[concat_symbol(self.out)]
				   | anychar_p[concat_string(self.out)]
				 );
		};

		boost::spirit::rule<ScannerT> encoded_string;
		boost::spirit::rule<ScannerT> const& start() const { return encoded_string; };
   };
};

}; //details


std::string escape_string_to_xml( std::string const& str)
{
	using namespace boost::spirit;

	std::ostringstream out;

	parse_info<> info = boost::spirit::parse(
               str.c_str(), 
			   details::escape_to_xml_grammar(out)
			   );
	out<<std::ends;

	return out.str();
};

std::string unescape_string_from_xml( std::string const& str)
{
	using namespace boost::spirit;

	std::ostringstream out;

	parse_info<> info = boost::spirit::parse(
               str.c_str(), 
               details::unescape_from_xml_grammar(out)
			   );
	out<<std::ends;

	return out.str();
};


};