libs/spirit/example/techniques/no_rules/no_rule3.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)
=============================================================================*/
// *** See the section "Look Ma' No Rules" in
// *** chapter "Techniques" of the Spirit documentation
// *** for information regarding this snippet
#include <iostream>
#include <boost/spirit/core.hpp>
using namespace boost::spirit;
namespace boost { namespace spirit
{
template <typename DerivedT>
struct sub_grammar : parser<DerivedT>
{
typedef sub_grammar self_t;
typedef DerivedT const& embed_t;
template <typename ScannerT>
struct result
{
typedef typename parser_result<
typename DerivedT::start_t, ScannerT>::type
type;
};
DerivedT const& derived() const
{ return *static_cast<DerivedT const*>(this); }
template <typename ScannerT>
typename parser_result<self_t, ScannerT>::type
parse(ScannerT const& scan) const
{
return derived().start.parse(scan);
}
};
}}
///////////////////////////////////////////////////////////////////////////////
//
// Client code
//
///////////////////////////////////////////////////////////////////////////////
struct skip_grammar : sub_grammar<skip_grammar>
{
typedef
alternative<alternative<space_parser, sequence<sequence<
strlit<const char*>, kleene_star<difference<anychar_parser,
chlit<char> > > >, chlit<char> > >, sequence<sequence<
strlit<const char*>, kleene_star<difference<anychar_parser,
strlit<const char*> > > >, strlit<const char*> > >
start_t;
skip_grammar()
: start
(
space_p
| "//" >> *(anychar_p - '\n') >> '\n'
| "/*" >> *(anychar_p - "*/") >> "*/"
)
{}
start_t start;
};
int
main()
{
skip_grammar g;
bool success = parse(
"/*this is a comment*/\n//this is a c++ comment\n\n",
*g).full;
assert(success);
std::cout << "SUCCESS!!!\n";
return 0;
}