Chris@16: /*=============================================================================
Chris@16:     Copyright (c) 1998-2003 Joel de Guzman
Chris@16:     http://spirit.sourceforge.net/
Chris@16: 
Chris@16:   Distributed under the Boost Software License, Version 1.0. (See accompanying
Chris@16:   file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Chris@16: =============================================================================*/
Chris@16: #if !defined(BOOST_SPIRIT_RULE_ALIAS_HPP)
Chris@16: #define BOOST_SPIRIT_RULE_ALIAS_HPP
Chris@16: 
Chris@16: #include <boost/spirit/home/classic/namespace.hpp>
Chris@16: #include <boost/spirit/home/classic/core/parser.hpp>
Chris@16: 
Chris@16: namespace boost { namespace spirit {
Chris@16: 
Chris@16: BOOST_SPIRIT_CLASSIC_NAMESPACE_BEGIN
Chris@16: 
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16:     //
Chris@16:     //  rule_alias class
Chris@16:     //
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16:     template <typename ParserT>
Chris@16:     class rule_alias :
Chris@16:         public parser<rule_alias<ParserT> >
Chris@16:     {
Chris@16:     public:
Chris@16:     
Chris@16:         typedef rule_alias<ParserT> self_t;
Chris@16:     
Chris@16:         template <typename ScannerT>
Chris@16:         struct result 
Chris@16:         { 
Chris@16:             typedef typename parser_result<ParserT, ScannerT>::type type;
Chris@16:         };
Chris@16:     
Chris@16:         rule_alias()
Chris@16:         : ptr(0) {}
Chris@16:         
Chris@16:         rule_alias(ParserT const& p)
Chris@16:         : ptr(&p) {}
Chris@16:         
Chris@16:         rule_alias&
Chris@16:         operator=(ParserT const& p)
Chris@16:         {
Chris@16:             ptr = &p;
Chris@16:             return *this;
Chris@16:         }
Chris@16:     
Chris@16:         template <typename ScannerT>
Chris@16:         typename parser_result<ParserT, ScannerT>::type
Chris@16:         parse(ScannerT const& scan) const
Chris@16:         { 
Chris@16:             if (ptr)
Chris@16:                 return ptr->parse(scan);
Chris@16:             else
Chris@16:                 return scan.no_match();
Chris@16:         }
Chris@16:         
Chris@16:         ParserT const&
Chris@16:         get() const
Chris@16:         {
Chris@16:             BOOST_ASSERT(ptr != 0);
Chris@16:             return *ptr;
Chris@16:         }
Chris@16:     
Chris@16:     private:
Chris@16:     
Chris@16:         ParserT const* ptr; // hold it by pointer
Chris@16:     };
Chris@16: 
Chris@16: BOOST_SPIRIT_CLASSIC_NAMESPACE_END
Chris@16: 
Chris@16: }} // namespace BOOST_SPIRIT_CLASSIC_NS
Chris@16: 
Chris@16: #endif