ceph/src/boost/libs/spirit/include/boost/spirit/home/classic/utility/functor_parser.hpp

   1 /*=============================================================================
   2     Copyright (c) 2002-2003 Joel de Guzman
   3     Copyright (c) 2002-2003 Juan Carlos Arevalo-Baeza
   4     http://spirit.sourceforge.net/
   5
   6   Distributed under the Boost Software License, Version 1.0. (See accompanying
   7   file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   8 =============================================================================*/
   9 #ifndef BOOST_SPIRIT_FUNCTOR_PARSER_HPP
  10 #define BOOST_SPIRIT_FUNCTOR_PARSER_HPP
  11
  12 ///////////////////////////////////////////////////////////////////////////////
  13 #include <boost/spirit/home/classic/namespace.hpp>
  14 #include <boost/spirit/home/classic/core/parser.hpp>
  15
  16 ///////////////////////////////////////////////////////////////////////////////
  17 namespace boost { namespace spirit {
  18
  19 BOOST_SPIRIT_CLASSIC_NAMESPACE_BEGIN
  20
  21     ///////////////////////////////////////////////////////////////////////////
  22     //
  23     //  functor_parser class
  24     //
  25     //      Once a functor parser has been defined, you can build a real
  26     //      parser from it by passing it to this class as the template
  27     //      parameter.
  28     //
  29     ///////////////////////////////////////////////////////////////////////////
  30     template < class FunctorT >
  31     struct functor_parser : public parser<functor_parser<FunctorT> >
  32     {
  33         FunctorT functor;
  34
  35         functor_parser(): functor() {}
  36         functor_parser(FunctorT const& functor_): functor(functor_) {}
  37
  38         typedef typename FunctorT::result_t functor_result_t;
  39         typedef functor_parser<FunctorT> self_t;
  40
  41         template <typename ScannerT>
  42         struct result
  43         {
  44             typedef typename match_result<ScannerT, functor_result_t>::type
  45             type;
  46         };
  47
  48         template <typename ScannerT>
  49         typename parser_result<self_t, ScannerT>::type
  50         parse(ScannerT const& scan) const
  51         {
  52             typedef typename ScannerT::iterator_t   iterator_t;
  53
  54             iterator_t const s(scan.first);
  55             functor_result_t functor_result;
  56             std::ptrdiff_t len = functor(scan, functor_result);
  57
  58             if (len < 0)
  59                 return scan.no_match();
  60             else
  61                 return scan.create_match(std::size_t(len), functor_result, s, scan.first);
  62         }
  63     };
  64
  65 BOOST_SPIRIT_CLASSIC_NAMESPACE_END
  66
  67 }} // namespace BOOST_SPIRIT_CLASSIC_NS
  68
  69 #endif