/*============================================================================= | |
Copyright (c) 2003 Hartmut Kaiser | |
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) | |
=============================================================================*/ | |
#ifndef BOOST_SPIRIT_SELECT_IPP | |
#define BOOST_SPIRIT_SELECT_IPP | |
#include <boost/spirit/home/classic/core/parser.hpp> | |
#include <boost/spirit/home/classic/core/composite/composite.hpp> | |
#include <boost/spirit/home/classic/meta/as_parser.hpp> | |
/////////////////////////////////////////////////////////////////////////////// | |
namespace boost { namespace spirit { | |
BOOST_SPIRIT_CLASSIC_NAMESPACE_BEGIN | |
/////////////////////////////////////////////////////////////////////////////// | |
namespace impl { | |
/////////////////////////////////////////////////////////////////////////////// | |
template <typename ParserT> | |
struct as_embedded_parser : public as_parser<ParserT> | |
{ | |
typedef typename as_parser<ParserT>::type::derived_t::embed_t type; | |
}; | |
/////////////////////////////////////////////////////////////////////////////// | |
// no implementation here to catch unknown BehaviourT template arguments | |
template <typename ResultT, typename BehaviourT> | |
struct select_match_gen; | |
// implementation for the select_default_no_fail behaviour | |
template <typename ResultT> | |
struct select_match_gen<ResultT, select_default_no_fail> { | |
template <typename ScannerT> | |
static ResultT | |
do_ (ScannerT const &scan) | |
{ | |
return scan.create_match(0, -1, scan.first, scan.first); | |
} | |
}; | |
// implementation for the select_default_fail behaviour | |
template <typename ResultT> | |
struct select_match_gen<ResultT, select_default_fail> { | |
template <typename ScannerT> | |
static ResultT | |
do_ (ScannerT const &scan) | |
{ | |
return scan.no_match(); | |
} | |
}; | |
/////////////////////////////////////////////////////////////////////////////// | |
template <int N, typename ResultT, typename TupleT, typename BehaviourT> | |
struct parse_tuple_element { | |
BOOST_STATIC_CONSTANT(int, index = (TupleT::length - N)); | |
template <typename ScannerT> | |
static ResultT | |
do_(TupleT const &t, ScannerT const &scan) | |
{ | |
typedef typename ::phoenix::tuple_element<index, TupleT>::type parser_t; | |
typedef typename ScannerT::iterator_t iterator_t; | |
typedef typename parser_result<parser_t, ScannerT>::type result_t; | |
iterator_t save(scan.first); | |
result_t result(t[::phoenix::tuple_index<index>()].parse(scan)); | |
if (result) { | |
return scan.create_match(result.length(), TupleT::length - N, | |
save, scan.first); | |
} | |
scan.first = save; // reset the input stream | |
return parse_tuple_element<N-1, ResultT, TupleT, BehaviourT>:: | |
do_(t, scan); | |
} | |
}; | |
template <typename ResultT, typename TupleT, typename BehaviourT> | |
struct parse_tuple_element<1, ResultT, TupleT, BehaviourT> { | |
BOOST_STATIC_CONSTANT(int, index = (TupleT::length - 1)); | |
template <typename ScannerT> | |
static ResultT | |
do_(TupleT const &t, ScannerT const &scan) | |
{ | |
typedef typename ::phoenix::tuple_element<index, TupleT>::type parser_t; | |
typedef typename ScannerT::iterator_t iterator_t; | |
typedef typename parser_result<parser_t, ScannerT>::type result_t; | |
iterator_t save(scan.first); | |
result_t result(t[::phoenix::tuple_index<index>()].parse(scan)); | |
if (result) { | |
return scan.create_match(result.length(), TupleT::length - 1, | |
save, scan.first); | |
} | |
scan.first = save; // reset the input stream | |
return select_match_gen<ResultT, BehaviourT>::do_(scan); | |
} | |
}; | |
/////////////////////////////////////////////////////////////////////////////// | |
} // namespace impl | |
BOOST_SPIRIT_CLASSIC_NAMESPACE_END | |
}} // namespace boost::spirit | |
#endif // BOOST_SPIRIT_SELECT_IPP |