Chris@16: /*=============================================================================
Chris@16:     Copyright (c) 2003 Hartmut Kaiser
Chris@16:     http://spirit.sourceforge.net/
Chris@16: 
Chris@16:     Use, modification and distribution is subject to the Boost Software
Chris@16:     License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
Chris@16:     http://www.boost.org/LICENSE_1_0.txt)
Chris@16: =============================================================================*/
Chris@16: #ifndef BOOST_SPIRIT_SELECT_IPP
Chris@16: #define BOOST_SPIRIT_SELECT_IPP
Chris@16: 
Chris@16: #include <boost/spirit/home/classic/core/parser.hpp>
Chris@16: #include <boost/spirit/home/classic/core/composite/composite.hpp>
Chris@16: #include <boost/spirit/home/classic/meta/as_parser.hpp>
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: namespace boost { namespace spirit {
Chris@16: 
Chris@16: BOOST_SPIRIT_CLASSIC_NAMESPACE_BEGIN
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: namespace impl {
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: template <typename ParserT>
Chris@16: struct as_embedded_parser : public as_parser<ParserT>
Chris@16: {
Chris@16:     typedef typename as_parser<ParserT>::type::derived_t::embed_t type;
Chris@16: };
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: 
Chris@16: // no implementation here to catch unknown BehaviourT template arguments
Chris@16: template <typename ResultT, typename BehaviourT>
Chris@16: struct select_match_gen;
Chris@16: 
Chris@16: // implementation for the select_default_no_fail behaviour
Chris@16: template <typename ResultT>
Chris@16: struct select_match_gen<ResultT, select_default_no_fail> {
Chris@16: 
Chris@16:     template <typename ScannerT>
Chris@16:     static ResultT
Chris@16:     do_ (ScannerT const &scan)
Chris@16:     {
Chris@16:         return scan.create_match(0, -1, scan.first, scan.first);
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: // implementation for the select_default_fail behaviour
Chris@16: template <typename ResultT>
Chris@16: struct select_match_gen<ResultT, select_default_fail> {
Chris@16: 
Chris@16:     template <typename ScannerT>
Chris@16:     static ResultT
Chris@16:     do_ (ScannerT const &scan)
Chris@16:     {
Chris@16:         return scan.no_match();
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: template <int N, typename ResultT, typename TupleT, typename BehaviourT>
Chris@16: struct parse_tuple_element {
Chris@16: 
Chris@16:     BOOST_STATIC_CONSTANT(int, index = (TupleT::length - N));
Chris@16:     
Chris@16:     template <typename ScannerT>
Chris@16:     static ResultT
Chris@16:     do_(TupleT const &t, ScannerT const &scan)
Chris@16:     {
Chris@16:         typedef typename ::phoenix::tuple_element<index, TupleT>::type parser_t;
Chris@16:         typedef typename ScannerT::iterator_t                       iterator_t;
Chris@16:         typedef typename parser_result<parser_t, ScannerT>::type    result_t;
Chris@16:     
Chris@16:     iterator_t save(scan.first);
Chris@16:     result_t result(t[::phoenix::tuple_index<index>()].parse(scan));
Chris@16: 
Chris@16:         if (result) {
Chris@16:             return scan.create_match(result.length(), TupleT::length - N, 
Chris@16:                 save, scan.first);
Chris@16:         }
Chris@16:         scan.first = save;    // reset the input stream 
Chris@16:         return parse_tuple_element<N-1, ResultT, TupleT, BehaviourT>::
Chris@16:             do_(t, scan);
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: template <typename ResultT, typename TupleT, typename BehaviourT>
Chris@16: struct parse_tuple_element<1, ResultT, TupleT, BehaviourT> {
Chris@16: 
Chris@16:     BOOST_STATIC_CONSTANT(int, index = (TupleT::length - 1));
Chris@16:     
Chris@16:     template <typename ScannerT>
Chris@16:     static ResultT
Chris@16:     do_(TupleT const &t, ScannerT const &scan)
Chris@16:     {
Chris@16:         typedef typename ::phoenix::tuple_element<index, TupleT>::type  parser_t;
Chris@16:         typedef typename ScannerT::iterator_t                       iterator_t;
Chris@16:         typedef typename parser_result<parser_t, ScannerT>::type    result_t;
Chris@16:         
Chris@16:     iterator_t save(scan.first);
Chris@16:     result_t result(t[::phoenix::tuple_index<index>()].parse(scan));
Chris@16: 
Chris@16:         if (result) {
Chris@16:             return scan.create_match(result.length(), TupleT::length - 1, 
Chris@16:                 save, scan.first);
Chris@16:         }
Chris@16:         scan.first = save;    // reset the input stream 
Chris@16:         return select_match_gen<ResultT, BehaviourT>::do_(scan);
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: }   // namespace impl
Chris@16: 
Chris@16: BOOST_SPIRIT_CLASSIC_NAMESPACE_END
Chris@16: 
Chris@16: }}  // namespace boost::spirit
Chris@16: 
Chris@16: #endif  // BOOST_SPIRIT_SELECT_IPP