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_SWITCH_IPP
Chris@16: #define BOOST_SPIRIT_SWITCH_IPP
Chris@16: 
Chris@16: #include <boost/mpl/if.hpp>
Chris@16: #include <boost/type_traits/is_same.hpp>
Chris@16: #include <boost/static_assert.hpp>
Chris@16: 
Chris@16: #include <boost/preprocessor/cat.hpp>
Chris@16: #include <boost/preprocessor/inc.hpp>
Chris@16: #include <boost/preprocessor/repeat.hpp>
Chris@16: #include <boost/preprocessor/repeat_from_to.hpp>
Chris@16: 
Chris@16: #include <boost/spirit/home/classic/core/parser.hpp>
Chris@16: #include <boost/spirit/home/classic/core/primitives/primitives.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: #include <boost/spirit/home/classic/phoenix/actor.hpp>
Chris@16: #include <boost/spirit/home/classic/phoenix/tuples.hpp>
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: namespace boost { namespace spirit {
Chris@16: 
Chris@16: BOOST_SPIRIT_CLASSIC_NAMESPACE_BEGIN
Chris@16: 
Chris@16: // forward declaration
Chris@16: template <int N, typename ParserT, bool IsDefault> struct case_parser;
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: namespace impl {
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: //  parse helper functions
Chris@16: template <typename ParserT, typename ScannerT>
Chris@16: inline typename parser_result<ParserT, ScannerT>::type
Chris@16: delegate_parse(ParserT const &p, ScannerT const &scan,
Chris@16:     typename ScannerT::iterator_t const save)
Chris@16: {
Chris@16:     typedef typename parser_result<ParserT, ScannerT>::type result_t;
Chris@16: 
Chris@16:     result_t result (p.subject().parse(scan));
Chris@16:     if (!result)
Chris@16:         scan.first = save;
Chris@16:     return result;
Chris@16: }
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: //  General default case handling (no default_p case branch given).
Chris@16: //  First try to match the current parser node (if the condition value is
Chris@16: //  matched) and, if that fails, return a no_match
Chris@16: template <int N, bool IsDefault, bool HasDefault>
Chris@16: struct default_delegate_parse {
Chris@16: 
Chris@16:     template <
Chris@16:         typename ParserT, typename DefaultT,
Chris@16:         typename ValueT, typename ScannerT
Chris@16:     >
Chris@16:     static typename parser_result<ParserT, ScannerT>::type
Chris@16:     parse (ValueT const &value, ParserT const &p, DefaultT const &,
Chris@16:         ScannerT const &scan, typename ScannerT::iterator_t const save)
Chris@16:     {
Chris@16:         if (value == N)
Chris@16:             return delegate_parse(p, scan, save);
Chris@16:         return scan.no_match();
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: //  The current case parser node is the default parser.
Chris@16: //  Ignore the given case value and try to match the given default parser.
Chris@16: template <int N, bool HasDefault>
Chris@16: struct default_delegate_parse<N, true, HasDefault> {
Chris@16: 
Chris@16:     template <
Chris@16:         typename ParserT, typename DefaultT,
Chris@16:         typename ValueT, typename ScannerT
Chris@16:     >
Chris@16:     static typename parser_result<ParserT, ScannerT>::type
Chris@16:     parse (ValueT const& /*value*/, ParserT const &, DefaultT const &d,
Chris@16:         ScannerT const &scan, typename ScannerT::iterator_t const save)
Chris@16:     {
Chris@16:         //  Since there is a default_p case branch defined, the corresponding
Chris@16:         //  parser shouldn't be the nothing_parser
Chris@16:         BOOST_STATIC_ASSERT((!boost::is_same<DefaultT, nothing_parser>::value));
Chris@16:         return delegate_parse(d, scan, save);
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: //  The current case parser node is not the default parser, but there is a
Chris@16: //  default_p branch given inside the switch_p parser.
Chris@16: //  First try to match the current parser node (if the condition value is
Chris@16: //  matched) and, if that fails, match the given default_p parser.
Chris@16: template <int N>
Chris@16: struct default_delegate_parse<N, false, true> {
Chris@16: 
Chris@16:     template <
Chris@16:         typename ParserT, typename DefaultT,
Chris@16:         typename ValueT, typename ScannerT
Chris@16:     >
Chris@16:     static typename parser_result<ParserT, ScannerT>::type
Chris@16:     parse (ValueT const &value, ParserT const &p, DefaultT const &d,
Chris@16:         ScannerT const &scan, typename ScannerT::iterator_t const save)
Chris@16:     {
Chris@16:         //  Since there is a default_p case branch defined, the corresponding
Chris@16:         //  parser shouldn't be the nothing_parser
Chris@16:         BOOST_STATIC_ASSERT((!boost::is_same<DefaultT, nothing_parser>::value));
Chris@16:         if (value == N)
Chris@16:             return delegate_parse(p, scan, save);
Chris@16: 
Chris@16:         return delegate_parse(d, scan, save);
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: //  Look through the case parser chain to test, if there is a default case
Chris@16: //  branch defined (returned by 'value').
Chris@16: template <typename CaseT, bool IsSimple = CaseT::is_simple>
Chris@16: struct default_case;
Chris@16: 
Chris@16: ////////////////////////////////////////
Chris@16: template <typename ResultT, bool IsDefault>
Chris@16: struct get_default_parser {
Chris@16: 
Chris@16:     template <typename ParserT>
Chris@16:     static ResultT
Chris@16:     get(parser<ParserT> const &p)
Chris@16:     {
Chris@16:         return default_case<typename ParserT::derived_t::left_t>::
Chris@16:             get(p.derived().left());
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: template <typename ResultT>
Chris@16: struct get_default_parser<ResultT, true> {
Chris@16: 
Chris@16:     template <typename ParserT>
Chris@16:     static ResultT
Chris@16:     get(parser<ParserT> const &p) { return p.derived().right(); }
Chris@16: };
Chris@16: 
Chris@16: ////////////////////////////////////////
Chris@16: template <typename CaseT, bool IsSimple>
Chris@16: struct default_case {
Chris@16: 
Chris@16:     //  The 'value' constant is true, if the current case_parser or one of its
Chris@16:     //  left siblings is a default_p generated case_parser.
Chris@16:     BOOST_STATIC_CONSTANT(bool, value =
Chris@16:         (CaseT::is_default || default_case<typename CaseT::left_t>::value));
Chris@16: 
Chris@16:     //  The 'is_epsilon' constant is true, if the current case_parser or one of
Chris@16:     //  its left siblings is a default_p generated parser with an attached
Chris@16:     //  epsilon_p (this is generated by the plain default_p).
Chris@16:     BOOST_STATIC_CONSTANT(bool, is_epsilon = (
Chris@16:         (CaseT::is_default && CaseT::is_epsilon) ||
Chris@16:             default_case<typename CaseT::left_t>::is_epsilon
Chris@16:     ));
Chris@16: 
Chris@16:     //  The computed 'type' represents the type of the default case branch
Chris@16:     //  parser (if there is one) or nothing_parser (if there isn't any default
Chris@16:     //  case branch).
Chris@16:     typedef typename boost::mpl::if_c<
Chris@16:             CaseT::is_default, typename CaseT::right_embed_t,
Chris@16:             typename default_case<typename CaseT::left_t>::type
Chris@16:         >::type type;
Chris@16: 
Chris@16:     //  The get function returns the parser attached to the default case branch
Chris@16:     //  (if there is one) or an instance of a nothing_parser (if there isn't
Chris@16:     //  any default case branch).
Chris@16:     template <typename ParserT>
Chris@16:     static type
Chris@16:     get(parser<ParserT> const &p)
Chris@16:     { return get_default_parser<type, CaseT::is_default>::get(p); }
Chris@16: };
Chris@16: 
Chris@16: ////////////////////////////////////////
Chris@16: template <typename ResultT, bool IsDefault>
Chris@16: struct get_default_parser_simple {
Chris@16: 
Chris@16:     template <typename ParserT>
Chris@16:     static ResultT
Chris@16:     get(parser<ParserT> const &p) { return p.derived(); }
Chris@16: };
Chris@16: 
Chris@16: template <typename ResultT>
Chris@16: struct get_default_parser_simple<ResultT, false> {
Chris@16: 
Chris@16:     template <typename ParserT>
Chris@16:     static nothing_parser
Chris@16:     get(parser<ParserT> const &) { return nothing_p; }
Chris@16: };
Chris@16: 
Chris@16: ////////////////////////////////////////
Chris@16: //  Specialization of the default_case template for the last (leftmost) element
Chris@16: //  of the case parser chain.
Chris@16: template <typename CaseT>
Chris@16: struct default_case<CaseT, true> {
Chris@16: 
Chris@16:     //  The 'value' and 'is_epsilon' constant, the 'type' type and the function
Chris@16:     //  'get' are described above.
Chris@16: 
Chris@16:     BOOST_STATIC_CONSTANT(bool, value = CaseT::is_default);
Chris@16:     BOOST_STATIC_CONSTANT(bool, is_epsilon = (
Chris@16:         CaseT::is_default && CaseT::is_epsilon
Chris@16:     ));
Chris@16: 
Chris@16:     typedef typename boost::mpl::if_c<
Chris@16:             CaseT::is_default, CaseT, nothing_parser
Chris@16:         >::type type;
Chris@16: 
Chris@16:     template <typename ParserT>
Chris@16:     static type
Chris@16:     get(parser<ParserT> const &p)
Chris@16:     { return get_default_parser_simple<type, value>::get(p); }
Chris@16: };
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: //  The case_chain template calculates recursivly the depth of the left
Chris@16: //  subchain of the given case branch node.
Chris@16: template <typename CaseT, bool IsSimple = CaseT::is_simple>
Chris@16: struct case_chain {
Chris@16: 
Chris@16:     BOOST_STATIC_CONSTANT(int, depth = (
Chris@16:         case_chain<typename CaseT::left_t>::depth + 1
Chris@16:     ));
Chris@16: };
Chris@16: 
Chris@16: template <typename CaseT>
Chris@16: struct case_chain<CaseT, true> {
Chris@16: 
Chris@16:     BOOST_STATIC_CONSTANT(int, depth = 0);
Chris@16: };
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: //  The chain_parser template is used to extract the type and the instance of
Chris@16: //  a left or a right parser, burried arbitrary deep inside the case parser
Chris@16: //  chain.
Chris@16: template <int Depth, typename CaseT>
Chris@16: struct chain_parser {
Chris@16: 
Chris@16:     typedef typename CaseT::left_t our_left_t;
Chris@16: 
Chris@16:     typedef typename chain_parser<Depth-1, our_left_t>::left_t  left_t;
Chris@16:     typedef typename chain_parser<Depth-1, our_left_t>::right_t right_t;
Chris@16: 
Chris@16:     static left_t
Chris@16:     left(CaseT const &p)
Chris@16:     { return chain_parser<Depth-1, our_left_t>::left(p.left()); }
Chris@16: 
Chris@16:     static right_t
Chris@16:     right(CaseT const &p)
Chris@16:     { return chain_parser<Depth-1, our_left_t>::right(p.left()); }
Chris@16: };
Chris@16: 
Chris@16: template <typename CaseT>
Chris@16: struct chain_parser<1, CaseT> {
Chris@16: 
Chris@16:     typedef typename CaseT::left_t  left_t;
Chris@16:     typedef typename CaseT::right_t right_t;
Chris@16: 
Chris@16:     static left_t left(CaseT const &p) { return p.left(); }
Chris@16:     static right_t right(CaseT const &p) { return p.right(); }
Chris@16: };
Chris@16: 
Chris@16: template <typename CaseT>
Chris@16: struct chain_parser<0, CaseT>;      // shouldn't be instantiated
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: //  Type computing meta function for calculating the type of the return value
Chris@16: //  of the used conditional switch expression
Chris@16: template <typename TargetT, typename ScannerT>
Chris@16: struct condition_result {
Chris@16: 
Chris@16:     typedef typename TargetT::template result<ScannerT>::type type;
Chris@16: };
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: template <typename LeftT, typename RightT, bool IsDefault>
Chris@16: struct compound_case_parser
Chris@16: :   public binary<LeftT, RightT,
Chris@16:         parser<compound_case_parser<LeftT, RightT, IsDefault> > >
Chris@16: {
Chris@16:     typedef compound_case_parser<LeftT, RightT, IsDefault>    self_t;
Chris@16:     typedef binary_parser_category                  parser_category_t;
Chris@16:     typedef binary<LeftT, RightT, parser<self_t> >  base_t;
Chris@16: 
Chris@16:     BOOST_STATIC_CONSTANT(int, value = RightT::value);
Chris@16:     BOOST_STATIC_CONSTANT(bool, is_default = IsDefault);
Chris@16:     BOOST_STATIC_CONSTANT(bool, is_simple = false);
Chris@16:     BOOST_STATIC_CONSTANT(bool, is_epsilon = (
Chris@16:         is_default &&
Chris@16:             boost::is_same<typename RightT::subject_t, epsilon_parser>::value
Chris@16:     ));
Chris@16: 
Chris@16:     compound_case_parser(parser<LeftT> const &lhs, parser<RightT> const &rhs)
Chris@16:     :   base_t(lhs.derived(), rhs.derived())
Chris@16:     {}
Chris@16: 
Chris@16:     template <typename ScannerT>
Chris@16:     struct result
Chris@16:     {
Chris@16:         typedef typename match_result<ScannerT, nil_t>::type type;
Chris@16:     };
Chris@16: 
Chris@16:     template <typename ScannerT, typename CondT>
Chris@16:     typename parser_result<self_t, ScannerT>::type
Chris@16:     parse(ScannerT const& scan, CondT const &cond) const;
Chris@16: 
Chris@16:     template <int N1, typename ParserT1, bool IsDefault1>
Chris@16:     compound_case_parser<
Chris@16:         self_t, case_parser<N1, ParserT1, IsDefault1>, IsDefault1
Chris@16:     >
Chris@16:     operator, (case_parser<N1, ParserT1, IsDefault1> const &p) const
Chris@16:     {
Chris@16:         //  If the following compile time assertion fires, you've probably used
Chris@16:         //  more than one default_p case inside the switch_p parser construct.
Chris@16:         BOOST_STATIC_ASSERT(!default_case<self_t>::value || !IsDefault1);
Chris@16: 
Chris@16:         //  If this compile time assertion fires, you've probably want to use
Chris@16:         //  more case_p/default_p case branches, than possible.
Chris@16:         BOOST_STATIC_ASSERT(
Chris@16:             case_chain<self_t>::depth < BOOST_SPIRIT_SWITCH_CASE_LIMIT
Chris@16:         );
Chris@16: 
Chris@16:         typedef case_parser<N1, ParserT1, IsDefault1> right_t;
Chris@16:         return compound_case_parser<self_t, right_t, IsDefault1>(*this, p);
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: //  The parse_switch::do_ functions dispatch to the correct parser, which is
Chris@16: //  selected through the given conditional switch value.
Chris@16: template <int Value, int Depth, bool IsDefault>
Chris@16: struct parse_switch;
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: //
Chris@16: //  The following generates a couple of parse_switch template specializations
Chris@16: //  with an increasing number of handled case branches (for 1..N).
Chris@16: //
Chris@16: //      template <int Value, bool IsDefault>
Chris@16: //      struct parse_switch<Value, N, IsDefault> {
Chris@16: //
Chris@16: //          template <typename ParserT, typename ScannerT>
Chris@16: //          static typename parser_result<ParserT, ScannerT>::type
Chris@16: //          do_(ParserT const &p, ScannerT const &scan, long cond_value,
Chris@16: //              typename ScannerT::iterator_t const &save)
Chris@16: //          {
Chris@16: //              typedef ParserT left_t0;
Chris@16: //              typedef typename left_t0::left left_t1;
Chris@16: //              ...
Chris@16: //
Chris@16: //              switch (cond_value) {
Chris@16: //              case left_tN::value:
Chris@16: //                  return delegate_parse(chain_parser<
Chris@16: //                          case_chain<ParserT>::depth, ParserT
Chris@16: //                      >::left(p), scan, save);
Chris@16: //              ...
Chris@16: //              case left_t1::value:
Chris@16: //                  return delegate_parse(chain_parser<
Chris@16: //                          1, left_t1
Chris@16: //                      >::right(p.left()), scan, save);
Chris@16: //
Chris@16: //              case left_t0::value:
Chris@16: //              default:
Chris@16: //                  typedef default_case<ParserT> default_t;
Chris@16: //                  typedef default_delegate_parse<
Chris@16: //                              Value, IsDefault, default_t::value>
Chris@16: //                      default_parse_t;
Chris@16: //
Chris@16: //                  return default_parse_t::parse(cond_value, p.right(),
Chris@16: //                      default_t::get(p), scan, save);
Chris@16: //              }
Chris@16: //          }
Chris@16: //      };
Chris@16: //
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: #define BOOST_SPIRIT_PARSE_SWITCH_TYPEDEFS(z, N, _)                         \
Chris@16:     typedef typename BOOST_PP_CAT(left_t, N)::left_t                        \
Chris@16:         BOOST_PP_CAT(left_t, BOOST_PP_INC(N));                              \
Chris@16:     /**/
Chris@16: 
Chris@16: #define BOOST_SPIRIT_PARSE_SWITCH_CASES(z, N, _)                            \
Chris@16:     case (long)(BOOST_PP_CAT(left_t, N)::value):                            \
Chris@16:         return delegate_parse(chain_parser<N, left_t1>::right(p.left()),    \
Chris@16:             scan, save);                                                    \
Chris@16:     /**/
Chris@16: 
Chris@16: #define BOOST_SPIRIT_PARSE_SWITCHES(z, N, _)                                \
Chris@16:     template <int Value, bool IsDefault>                                    \
Chris@16:     struct parse_switch<Value, BOOST_PP_INC(N), IsDefault> {                \
Chris@16:                                                                             \
Chris@16:         template <typename ParserT, typename ScannerT>                      \
Chris@16:         static typename parser_result<ParserT, ScannerT>::type              \
Chris@16:         do_(ParserT const &p, ScannerT const &scan, long cond_value,        \
Chris@16:             typename ScannerT::iterator_t const &save)                      \
Chris@16:         {                                                                   \
Chris@16:             typedef ParserT left_t0;                                        \
Chris@16:             BOOST_PP_REPEAT_FROM_TO_ ## z(0, BOOST_PP_INC(N),               \
Chris@16:                 BOOST_SPIRIT_PARSE_SWITCH_TYPEDEFS, _)                      \
Chris@16:                                                                             \
Chris@16:             switch (cond_value) {                                           \
Chris@16:             case (long)(BOOST_PP_CAT(left_t, BOOST_PP_INC(N))::value):      \
Chris@16:                 return delegate_parse(                                      \
Chris@16:                     chain_parser<                                           \
Chris@16:                         case_chain<ParserT>::depth, ParserT                 \
Chris@101:                     >::left(p), scan, save);                                \
Chris@16:                                                                             \
Chris@16:             BOOST_PP_REPEAT_FROM_TO_ ## z(1, BOOST_PP_INC(N),               \
Chris@16:                 BOOST_SPIRIT_PARSE_SWITCH_CASES, _)                         \
Chris@16:                                                                             \
Chris@16:             case (long)(left_t0::value):                                    \
Chris@16:             default:                                                        \
Chris@16:                 typedef default_case<ParserT> default_t;                    \
Chris@16:                 typedef                                                     \
Chris@16:                     default_delegate_parse<Value, IsDefault, default_t::value> \
Chris@16:                     default_parse_t;                                        \
Chris@16:                                                                             \
Chris@16:                 return default_parse_t::parse(cond_value, p.right(),        \
Chris@16:                     default_t::get(p), scan, save);                         \
Chris@16:             }                                                               \
Chris@16:         }                                                                   \
Chris@16:     };                                                                      \
Chris@16:     /**/
Chris@16: 
Chris@16: BOOST_PP_REPEAT(BOOST_PP_DEC(BOOST_SPIRIT_SWITCH_CASE_LIMIT),
Chris@16:     BOOST_SPIRIT_PARSE_SWITCHES, _)
Chris@16: 
Chris@16: #undef BOOST_SPIRIT_PARSE_SWITCH_TYPEDEFS
Chris@16: #undef BOOST_SPIRIT_PARSE_SWITCH_CASES
Chris@16: #undef BOOST_SPIRIT_PARSE_SWITCHES
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: 
Chris@16: template <typename LeftT, typename RightT, bool IsDefault>
Chris@16: template <typename ScannerT, typename CondT>
Chris@16: inline typename parser_result<
Chris@16:     compound_case_parser<LeftT, RightT, IsDefault>, ScannerT
Chris@16: >::type
Chris@16: compound_case_parser<LeftT, RightT, IsDefault>::
Chris@16:     parse(ScannerT const& scan, CondT const &cond) const
Chris@16: {
Chris@16:     scan.at_end();    // allow skipper to take effect
Chris@16:     return parse_switch<value, case_chain<self_t>::depth, is_default>::
Chris@16:         do_(*this, scan, cond(scan), scan.first);
Chris@16: }
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: //  The switch condition is to be evaluated from a parser result value.
Chris@16: template <typename ParserT>
Chris@16: struct cond_functor {
Chris@16: 
Chris@16:     typedef cond_functor<ParserT> self_t;
Chris@16: 
Chris@16:     cond_functor(ParserT const &p_)
Chris@16:     :   p(p_)
Chris@16:     {}
Chris@16: 
Chris@16:     template <typename ScannerT>
Chris@16:     struct result
Chris@16:     {
Chris@16:         typedef typename parser_result<ParserT, ScannerT>::type::attr_t type;
Chris@16:     };
Chris@16: 
Chris@16:     template <typename ScannerT>
Chris@16:     typename condition_result<self_t, ScannerT>::type
Chris@16:     operator()(ScannerT const &scan) const
Chris@16:     {
Chris@16:         typedef typename parser_result<ParserT, ScannerT>::type result_t;
Chris@16:         typedef typename result_t::attr_t attr_t;
Chris@16: 
Chris@16:         result_t result(p.parse(scan));
Chris@16:         return !result ? attr_t() : result.value();
Chris@16:     }
Chris@16: 
Chris@16:     typename ParserT::embed_t p;
Chris@16: };
Chris@16: 
Chris@16: template <typename ParserT>
Chris@16: struct make_cond_functor {
Chris@16: 
Chris@16:     typedef as_parser<ParserT> as_parser_t;
Chris@16: 
Chris@16:     static cond_functor<typename as_parser_t::type>
Chris@16:     do_(ParserT const &cond)
Chris@16:     {
Chris@16:         return cond_functor<typename as_parser_t::type>(
Chris@16:             as_parser_t::convert(cond));
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: //  The switch condition is to be evaluated from a phoenix actor
Chris@16: template <typename ActorT>
Chris@16: struct cond_actor {
Chris@16: 
Chris@16:     typedef cond_actor<ActorT> self_t;
Chris@16: 
Chris@16:     cond_actor(ActorT const &actor_)
Chris@16:     :   actor(actor_)
Chris@16:     {}
Chris@16: 
Chris@16:     template <typename ScannerT>
Chris@16:     struct result
Chris@16:     {
Chris@16:         typedef typename ::phoenix::actor_result<ActorT, ::phoenix::tuple<> >::type
Chris@16:             type;
Chris@16:     };
Chris@16: 
Chris@16:     template <typename ScannerT>
Chris@16:     typename condition_result<self_t, ScannerT>::type
Chris@16:     operator()(ScannerT const& /*scan*/) const
Chris@16:     {
Chris@16:         return actor();
Chris@16:     }
Chris@16: 
Chris@16:     ActorT const &actor;
Chris@16: };
Chris@16: 
Chris@16: template <typename ActorT>
Chris@16: struct make_cond_functor< ::phoenix::actor<ActorT> > {
Chris@16: 
Chris@16:     static cond_actor< ::phoenix::actor<ActorT> >
Chris@16:     do_(::phoenix::actor<ActorT> const &actor)
Chris@16:     {
Chris@16:         return cond_actor< ::phoenix::actor<ActorT> >(actor);
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: //  The switch condition is to be taken directly from the input stream
Chris@16: struct get_next_token_cond {
Chris@16: 
Chris@16:     typedef get_next_token_cond self_t;
Chris@16: 
Chris@16:     template <typename ScannerT>
Chris@16:     struct result
Chris@16:     {
Chris@16:         typedef typename ScannerT::value_t type;
Chris@16:     };
Chris@16: 
Chris@16:     template <typename ScannerT>
Chris@16:     typename condition_result<self_t, ScannerT>::type
Chris@16:     operator()(ScannerT const &scan) const
Chris@16:     {
Chris@16:         typename ScannerT::value_t val(*scan);
Chris@16:         ++scan.first;
Chris@16:         return val;
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: template <>
Chris@16: struct make_cond_functor<get_next_token_cond> {
Chris@16: 
Chris@16:     static get_next_token_cond
Chris@16:     do_(get_next_token_cond const &cond)
Chris@16:     {
Chris@16:         return cond;
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_SWITCH_IPP