Chris@16: //  Copyright (c) 2001-2011 Hartmut Kaiser
Chris@16: //  Copyright (c)      2011 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: #if !defined(BOOST_SPIRIT_LEX_ARGUMENT_PHEONIX_MARCH_25_2011_1841PM)
Chris@16: #define BOOST_SPIRIT_LEX_ARGUMENT_PHEONIX_MARCH_25_2011_1841PM
Chris@16: 
Chris@16: #if defined(_MSC_VER)
Chris@16: #pragma once
Chris@16: #endif
Chris@16: 
Chris@16: #include <boost/spirit/include/phoenix_core.hpp>
Chris@16: 
Chris@16: namespace boost { namespace spirit { namespace lex
Chris@16: {
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16:     //  The value_context is used as a noop Phoenix actor to create the 
Chris@16:     //  placeholder '_val' (see below). It is a noop actor because it is used
Chris@16:     //  as a placeholder only, while it is being converted either to a 
Chris@16:     //  value_getter (if used as a rvalue) or to a value_setter (if used as a 
Chris@16:     //  lvalue). The conversion is achieved by specializing and overloading a 
Chris@16:     //  couple of the Phoenix templates from the Phoenix expression composition
Chris@16:     //  engine (see the end of this file).
Chris@16:     struct value_context 
Chris@16:     {
Chris@16:         typedef mpl::true_ no_nullary;
Chris@16: 
Chris@16:         typedef unused_type result_type;
Chris@16: 
Chris@16:         template <typename Env>
Chris@16:         struct result
Chris@16:         {
Chris@16:             typedef unused_type type;
Chris@16:         };
Chris@16: 
Chris@16:         template <typename Env>
Chris@16:         unused_type
Chris@16:         eval(Env const& env) const
Chris@16:         {
Chris@16:             return unused;
Chris@16:         }
Chris@16:     };
Chris@16: 
Chris@16:     // forward declarations
Chris@16:     struct value_getter;
Chris@16:     template <typename> struct value_setter;
Chris@16: 
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16:     //  The state_context is used as a noop Phoenix actor to create the 
Chris@16:     //  placeholder '_state' (see below). It is a noop actor because it is used
Chris@16:     //  as a placeholder only, while it is being converted either to a 
Chris@16:     //  state_getter (if used as a rvalue) or to a state_setter (if used as a 
Chris@16:     //  lvalue). The conversion is achieved by specializing and overloading a 
Chris@16:     //  couple of the Phoenix templates from the Phoenix expression composition
Chris@16:     //  engine (see the end of this file).
Chris@16:     struct state_context 
Chris@16:     {
Chris@16:         typedef mpl::true_ no_nullary;
Chris@16: 
Chris@16:         typedef unused_type result_type;
Chris@16: 
Chris@16:         template <typename Env>
Chris@16:         struct result
Chris@16:         {
Chris@16:             typedef unused_type type;
Chris@16:         };
Chris@16: 
Chris@16:         template <typename Env>
Chris@16:         unused_type
Chris@16:         eval(Env const& env) const
Chris@16:         {
Chris@16:             return unused;
Chris@16:         }
Chris@16:     };
Chris@16: 
Chris@16:     // forward declarations
Chris@16:     struct state_getter;
Chris@16:     template <typename> struct state_setter;
Chris@16:     struct eoi_getter;
Chris@16: }}}
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: 
Chris@16: BOOST_PHOENIX_DEFINE_EXPRESSION(
Chris@16:     (boost)(spirit)(lex)(value_setter)
Chris@16:   , (boost::phoenix::meta_grammar)
Chris@16: )
Chris@16: 
Chris@16: BOOST_PHOENIX_DEFINE_EXPRESSION(
Chris@16:     (boost)(spirit)(lex)(state_setter)
Chris@16:   , (boost::phoenix::meta_grammar)
Chris@16: )
Chris@16: 
Chris@16: namespace boost { namespace phoenix
Chris@16: {
Chris@16:     namespace result_of
Chris@16:     {
Chris@16:         template <>
Chris@16:         struct is_nullary<custom_terminal<boost::spirit::lex::value_context> >
Chris@16:           : mpl::false_
Chris@16:         {};
Chris@16:     }
Chris@16:     
Chris@16:     template <typename Dummy>
Chris@16:     struct is_custom_terminal<boost::spirit::lex::value_context, Dummy>: mpl::true_ {};
Chris@16:     
Chris@16:     template <typename Dummy>
Chris@16:     struct custom_terminal<boost::spirit::lex::value_context, Dummy>
Chris@16:       : proto::call<
Chris@16:             v2_eval(
Chris@16:                 proto::make<boost::spirit::lex::value_getter()>
Chris@16:               , proto::call<functional::env(proto::_state)>
Chris@16:             )
Chris@16:         >
Chris@16:     {};
Chris@16: 
Chris@16:     template <typename Dummy>
Chris@16:     struct is_nullary::when<spirit::lex::rule::value_setter, Dummy>
Chris@16:       : proto::make<mpl::false_()>
Chris@16:     {};
Chris@16: 
Chris@16:     template <typename Dummy>
Chris@16:     struct default_actions::when<spirit::lex::rule::value_setter, Dummy>
Chris@16:       : proto::call<
Chris@16:             v2_eval(
Chris@16:                 proto::make<
Chris@16:                     spirit::lex::value_setter<proto::_child0>(
Chris@16:                         proto::_child0
Chris@16:                     )
Chris@16:                 >
Chris@16:               , _env
Chris@16:             )
Chris@16:         >
Chris@16:     {};
Chris@16: 
Chris@16:     template <>
Chris@16:     struct actor<spirit::lex::value_context>
Chris@16:       : boost::phoenix::actor<proto::terminal<spirit::lex::value_context>::type>
Chris@16:     {
Chris@16:         typedef boost::phoenix::actor<
Chris@16:             proto::terminal<spirit::lex::value_context>::type
Chris@16:         > base_type;
Chris@16: 
Chris@16:         actor(base_type const & base = base_type())
Chris@16:             : base_type(base)
Chris@16:         {}
Chris@16: 
Chris@16:         template <typename Expr>
Chris@16:         typename spirit::lex::expression::value_setter<
Chris@16:             typename phoenix::as_actor<Expr>::type>::type const
Chris@16:         operator=(Expr const & expr) const
Chris@16:         {
Chris@16:             return
Chris@16:                 spirit::lex::expression::value_setter<
Chris@16:                     typename phoenix::as_actor<Expr>::type
Chris@16:                 >::make(phoenix::as_actor<Expr>::convert(expr));
Chris@16:         }
Chris@16:     };
Chris@16:     
Chris@16:     namespace result_of
Chris@16:     {
Chris@16:         template <>
Chris@16:         struct is_nullary<custom_terminal<boost::spirit::lex::state_context> >
Chris@16:           : mpl::false_
Chris@16:         {};
Chris@16:     }
Chris@16:     
Chris@16:     template <typename Dummy>
Chris@16:     struct is_custom_terminal<boost::spirit::lex::state_context, Dummy>: mpl::true_ {};
Chris@16:     
Chris@16:     template <typename Dummy>
Chris@16:     struct custom_terminal<boost::spirit::lex::state_context, Dummy>
Chris@16:       : proto::call<
Chris@16:             v2_eval(
Chris@16:                 proto::make<boost::spirit::lex::state_getter()>
Chris@16:               , proto::call<functional::env(proto::_state)>
Chris@16:             )
Chris@16:         >
Chris@16:     {};
Chris@16: 
Chris@16:     template <typename Dummy>
Chris@16:     struct is_nullary::when<spirit::lex::rule::state_setter, Dummy>
Chris@16:       : proto::make<mpl::false_()>
Chris@16:     {};
Chris@16: 
Chris@16:     template <typename Dummy>
Chris@16:     struct default_actions::when<spirit::lex::rule::state_setter, Dummy>
Chris@16:       : proto::call<
Chris@16:             v2_eval(
Chris@16:                 proto::make<
Chris@16:                     spirit::lex::state_setter<proto::_child0>(
Chris@16:                         proto::_child0
Chris@16:                     )
Chris@16:                 >
Chris@16:               , _env
Chris@16:             )
Chris@16:         >
Chris@16:     {};
Chris@16: 
Chris@16:     template <>
Chris@16:     struct actor<spirit::lex::state_context>
Chris@16:       : boost::phoenix::actor<proto::terminal<spirit::lex::state_context>::type>
Chris@16:     {
Chris@16:         typedef boost::phoenix::actor<
Chris@16:             proto::terminal<spirit::lex::state_context>::type
Chris@16:         > base_type;
Chris@16: 
Chris@16:         actor(base_type const & base = base_type())
Chris@16:           : base_type(base)
Chris@16:         {}
Chris@16: 
Chris@16:         template <typename Expr>
Chris@16:         typename spirit::lex::expression::state_setter<
Chris@16:             typename phoenix::as_actor<Expr>::type>::type const
Chris@16:         operator=(Expr const & expr) const
Chris@16:         {
Chris@16:             return
Chris@16:                 spirit::lex::expression::state_setter<
Chris@16:                     typename phoenix::as_actor<Expr>::type
Chris@16:                 >::make(phoenix::as_actor<Expr>::convert(expr));
Chris@16:         }
Chris@16:     };
Chris@16:     
Chris@16:     namespace result_of
Chris@16:     {
Chris@16:         template <>
Chris@16:         struct is_nullary<custom_terminal<boost::spirit::lex::eoi_getter> >
Chris@16:           : mpl::false_
Chris@16:         {};
Chris@16:     }
Chris@16:     
Chris@16:     template <typename Dummy>
Chris@16:     struct is_custom_terminal<boost::spirit::lex::eoi_getter, Dummy>: mpl::true_ {};
Chris@16:     
Chris@16:     template <typename Dummy>
Chris@16:     struct custom_terminal<boost::spirit::lex::eoi_getter, Dummy>
Chris@16:       : proto::call<
Chris@16:             v2_eval(
Chris@16:                 proto::make<boost::spirit::lex::eoi_getter()>
Chris@16:               , proto::call<functional::env(proto::_state)>
Chris@16:             )
Chris@16:         >
Chris@16:     {};
Chris@16: }}
Chris@16: 
Chris@16: #endif