| // Copyright (c) 2001-2011 Hartmut Kaiser |
| // Copyright (c) 2011 Thomas Heller |
| // |
| // Distributed under the Boost Software License, Version 1.0. (See accompanying |
| // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) |
| |
| #if !defined(BOOST_SPIRIT_LEX_ARGUMENT_PHEONIX_MARCH_25_2011_1841PM) |
| #define BOOST_SPIRIT_LEX_ARGUMENT_PHEONIX_MARCH_25_2011_1841PM |
| |
| #if defined(_MSC_VER) |
| #pragma once |
| #endif |
| |
| #include <boost/spirit/include/phoenix_core.hpp> |
| |
| namespace boost { namespace spirit { namespace lex |
| { |
| /////////////////////////////////////////////////////////////////////////// |
| // The value_context is used as a noop Phoenix actor to create the |
| // placeholder '_val' (see below). It is a noop actor because it is used |
| // as a placeholder only, while it is being converted either to a |
| // value_getter (if used as a rvalue) or to a value_setter (if used as a |
| // lvalue). The conversion is achieved by specializing and overloading a |
| // couple of the Phoenix templates from the Phoenix expression composition |
| // engine (see the end of this file). |
| struct value_context |
| { |
| typedef mpl::true_ no_nullary; |
| |
| typedef unused_type result_type; |
| |
| template <typename Env> |
| struct result |
| { |
| typedef unused_type type; |
| }; |
| |
| template <typename Env> |
| unused_type |
| eval(Env const& env) const |
| { |
| return unused; |
| } |
| }; |
| |
| // forward declarations |
| struct value_getter; |
| template <typename> struct value_setter; |
| |
| /////////////////////////////////////////////////////////////////////////// |
| // The state_context is used as a noop Phoenix actor to create the |
| // placeholder '_state' (see below). It is a noop actor because it is used |
| // as a placeholder only, while it is being converted either to a |
| // state_getter (if used as a rvalue) or to a state_setter (if used as a |
| // lvalue). The conversion is achieved by specializing and overloading a |
| // couple of the Phoenix templates from the Phoenix expression composition |
| // engine (see the end of this file). |
| struct state_context |
| { |
| typedef mpl::true_ no_nullary; |
| |
| typedef unused_type result_type; |
| |
| template <typename Env> |
| struct result |
| { |
| typedef unused_type type; |
| }; |
| |
| template <typename Env> |
| unused_type |
| eval(Env const& env) const |
| { |
| return unused; |
| } |
| }; |
| |
| // forward declarations |
| struct state_getter; |
| template <typename> struct state_setter; |
| struct eoi_getter; |
| }}} |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| #ifdef BOOST_SPIRIT_USE_PHOENIX_V3 |
| |
| BOOST_PHOENIX_DEFINE_EXPRESSION( |
| (boost)(spirit)(lex)(value_setter) |
| , (boost::phoenix::meta_grammar) |
| ) |
| |
| BOOST_PHOENIX_DEFINE_EXPRESSION( |
| (boost)(spirit)(lex)(state_setter) |
| , (boost::phoenix::meta_grammar) |
| ) |
| |
| namespace boost { namespace phoenix |
| { |
| namespace result_of |
| { |
| template <> |
| struct is_nullary<custom_terminal<boost::spirit::lex::value_context> > |
| : mpl::false_ |
| {}; |
| } |
| |
| template <typename Dummy> |
| struct is_custom_terminal<boost::spirit::lex::value_context, Dummy>: mpl::true_ {}; |
| |
| template <typename Dummy> |
| struct custom_terminal<boost::spirit::lex::value_context, Dummy> |
| : proto::call< |
| v2_eval( |
| proto::make<boost::spirit::lex::value_getter()> |
| , proto::call<functional::env(proto::_state)> |
| ) |
| > |
| {}; |
| |
| template <typename Dummy> |
| struct is_nullary::when<spirit::lex::rule::value_setter, Dummy> |
| : proto::make<mpl::false_()> |
| {}; |
| |
| template <typename Dummy> |
| struct default_actions::when<spirit::lex::rule::value_setter, Dummy> |
| : proto::call< |
| v2_eval( |
| proto::make< |
| spirit::lex::value_setter<proto::_child0>( |
| proto::_child0 |
| ) |
| > |
| , _env |
| ) |
| > |
| {}; |
| |
| template <> |
| struct actor<spirit::lex::value_context> |
| : boost::phoenix::actor<proto::terminal<spirit::lex::value_context>::type> |
| { |
| typedef boost::phoenix::actor< |
| proto::terminal<spirit::lex::value_context>::type |
| > base_type; |
| |
| actor(base_type const & base = base_type()) |
| : base_type(base) |
| {} |
| |
| template <typename Expr> |
| typename spirit::lex::expression::value_setter< |
| typename phoenix::as_actor<Expr>::type>::type const |
| operator=(Expr const & expr) const |
| { |
| return |
| spirit::lex::expression::value_setter< |
| typename phoenix::as_actor<Expr>::type |
| >::make(phoenix::as_actor<Expr>::convert(expr)); |
| } |
| }; |
| |
| namespace result_of |
| { |
| template <> |
| struct is_nullary<custom_terminal<boost::spirit::lex::state_context> > |
| : mpl::false_ |
| {}; |
| } |
| |
| template <typename Dummy> |
| struct is_custom_terminal<boost::spirit::lex::state_context, Dummy>: mpl::true_ {}; |
| |
| template <typename Dummy> |
| struct custom_terminal<boost::spirit::lex::state_context, Dummy> |
| : proto::call< |
| v2_eval( |
| proto::make<boost::spirit::lex::state_getter()> |
| , proto::call<functional::env(proto::_state)> |
| ) |
| > |
| {}; |
| |
| template <typename Dummy> |
| struct is_nullary::when<spirit::lex::rule::state_setter, Dummy> |
| : proto::make<mpl::false_()> |
| {}; |
| |
| template <typename Dummy> |
| struct default_actions::when<spirit::lex::rule::state_setter, Dummy> |
| : proto::call< |
| v2_eval( |
| proto::make< |
| spirit::lex::state_setter<proto::_child0>( |
| proto::_child0 |
| ) |
| > |
| , _env |
| ) |
| > |
| {}; |
| |
| template <> |
| struct actor<spirit::lex::state_context> |
| : boost::phoenix::actor<proto::terminal<spirit::lex::state_context>::type> |
| { |
| typedef boost::phoenix::actor< |
| proto::terminal<spirit::lex::state_context>::type |
| > base_type; |
| |
| actor(base_type const & base = base_type()) |
| : base_type(base) |
| {} |
| |
| template <typename Expr> |
| typename spirit::lex::expression::state_setter< |
| typename phoenix::as_actor<Expr>::type>::type const |
| operator=(Expr const & expr) const |
| { |
| return |
| spirit::lex::expression::state_setter< |
| typename phoenix::as_actor<Expr>::type |
| >::make(phoenix::as_actor<Expr>::convert(expr)); |
| } |
| }; |
| |
| namespace result_of |
| { |
| template <> |
| struct is_nullary<custom_terminal<boost::spirit::lex::eoi_getter> > |
| : mpl::false_ |
| {}; |
| } |
| |
| template <typename Dummy> |
| struct is_custom_terminal<boost::spirit::lex::eoi_getter, Dummy>: mpl::true_ {}; |
| |
| template <typename Dummy> |
| struct custom_terminal<boost::spirit::lex::eoi_getter, Dummy> |
| : proto::call< |
| v2_eval( |
| proto::make<boost::spirit::lex::eoi_getter()> |
| , proto::call<functional::env(proto::_state)> |
| ) |
| > |
| {}; |
| }} |
| |
| #endif // BOOST_SPIRIT_USE_PHOENIX_V3 |
| |
| #endif |
