Chris@16: /*==============================================================================
Chris@16:     Copyright (c) 2005-2010 Joel de Guzman
Chris@16:     Copyright (c) 2010 Thomas Heller
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: #ifndef BOOST_PHOENIX_CORE_TERMINAL_HPP
Chris@16: #define BOOST_PHOENIX_CORE_TERMINAL_HPP
Chris@16: 
Chris@16: #include <boost/phoenix/core/limits.hpp>
Chris@16: #include <boost/call_traits.hpp>
Chris@16: #include <boost/is_placeholder.hpp>
Chris@16: #include <boost/phoenix/core/actor.hpp>
Chris@16: #include <boost/phoenix/core/meta_grammar.hpp>
Chris@16: #include <boost/phoenix/core/terminal_fwd.hpp>
Chris@16: #include <boost/proto/matches.hpp>
Chris@16: #include <boost/proto/transform/lazy.hpp>
Chris@16: #include <boost/proto/functional/fusion/at.hpp>
Chris@16: #include <boost/type_traits/remove_pointer.hpp>
Chris@16: 
Chris@16: #define BOOST_PHOENIX_DEFINE_CUSTOM_TERMINAL(Template, Terminal, IsNullary, EvalFun)\
Chris@16:     namespace boost { namespace phoenix                                         \
Chris@16:     {                                                                           \
Chris@16:         namespace result_of                                                     \
Chris@16:         {                                                                       \
Chris@16:             Template                                                            \
Chris@16:             struct is_nullary<                                                  \
Chris@16:                 custom_terminal<                                                \
Chris@16:                     Terminal                                                    \
Chris@16:                 >                                                               \
Chris@16:             >                                                                   \
Chris@16:                 : IsNullary                                                     \
Chris@16:             {};                                                                 \
Chris@16:         }                                                                       \
Chris@16:         Template                                                                \
Chris@16:         struct is_custom_terminal<Terminal >: mpl::true_ {};                    \
Chris@16:                                                                                 \
Chris@16:         Template                                                                \
Chris@16:         struct custom_terminal<Terminal > : proto::call<EvalFun > {};           \
Chris@16:     }}                                                                          \
Chris@16: /**/
Chris@16: 
Chris@16: namespace boost { namespace phoenix
Chris@16: {
Chris@16:     template <typename T, typename Dummy>
Chris@16:     struct is_custom_terminal
Chris@16:         : mpl::false_ {};
Chris@16: 
Chris@16:     template <typename T, typename Dummy>
Chris@16:     struct custom_terminal;
Chris@101: 
Chris@101:     namespace tag {
Chris@101:       struct terminal /*: public proto::tag::terminal */ {};
Chris@101:     }
Chris@16:  
Chris@16:     namespace expression
Chris@16:     {
Chris@16:         template <typename T, template <typename> class Actor = actor>
Chris@16:         struct terminal
Chris@16:             : proto::terminal<
Chris@16:                 T//typename call_traits<T>::value_type
Chris@16:             >
Chris@16:         {
Chris@16:             typedef
Chris@16:                 proto::basic_expr<
Chris@101:                 proto::tag::terminal
Chris@101:             // tag::terminal //cannot change to use phoenix tag - breaks code.
Chris@16:                   , proto::term<T>
Chris@16:                   , 0
Chris@16:                 >
Chris@16:                 base_type;
Chris@16:             typedef Actor<base_type> type;
Chris@16:             
Chris@16:             static const type make(typename call_traits<T>::param_type t)
Chris@16:             {
Chris@101:             // ?? Should the next line be Actor not actor which is the default?
Chris@16:                 actor<base_type> const e = {base_type::make(t)};
Chris@101:                 //Actor<base_type> const e = {base_type::make(t)};
Chris@16:                 return e;
Chris@16:             }
Chris@16:         };
Chris@16:     }
Chris@16: 
Chris@16:     namespace rule
Chris@16:     {
Chris@16:         struct argument
Chris@16:             : proto::if_<boost::is_placeholder<proto::_value>()>
Chris@16:         {};
Chris@16: 
Chris@16:         struct custom_terminal
Chris@16:             : proto::if_<boost::phoenix::is_custom_terminal<proto::_value>()>
Chris@16:         {};
Chris@16:         
Chris@16:         struct terminal
Chris@16:             : proto::terminal<proto::_>
Chris@16:         {};
Chris@16:     }
Chris@16: 
Chris@16:     template <typename Dummy>
Chris@16:     struct meta_grammar::case_<proto::tag::terminal, Dummy>
Chris@16:         : proto::or_<
Chris@16:             enable_rule<rule::argument       , Dummy>
Chris@16:           , enable_rule<rule::custom_terminal, Dummy>
Chris@16:           , enable_rule<rule::terminal       , Dummy>
Chris@16:         >
Chris@16:     {};
Chris@16: 
Chris@16:     template <typename Dummy>
Chris@16:     struct default_actions::when<rule::custom_terminal, Dummy>
Chris@16:         : proto::lazy<
Chris@16:             custom_terminal<proto::_value>(
Chris@16:                 proto::_value
Chris@16:               , _context
Chris@16:             )
Chris@16:         >
Chris@16:     {};
Chris@16: 
Chris@16:     namespace detail
Chris@16:     {
Chris@16:         template <typename N>
Chris@16:         struct placeholder_idx
Chris@16:             : mpl::int_<N::value>
Chris@16:         {};
Chris@16:     }
Chris@16:     
Chris@16:     template <typename Grammar>
Chris@16:     struct default_actions::when<rule::argument, Grammar>
Chris@16:         : proto::call<
Chris@16:             proto::functional::at(
Chris@16:                 _env
Chris@16:               , proto::make<
Chris@16:                     detail::placeholder_idx<
Chris@16:                         proto::make<
Chris@16:                             boost::is_placeholder<proto::_value>()
Chris@16:                         >
Chris@16:                     >()
Chris@16:                 >
Chris@16:             )
Chris@16:         >
Chris@16:     {};
Chris@16: }}
Chris@16: 
Chris@16: #endif