/Src/Dependencies/Boost/boost/spirit/home/lex/argument_phoenix.hpp
C++ Header | 251 lines | 190 code | 37 blank | 24 comment | 0 complexity | 158e714c61cafa3d72bb28be6928f6fa MD5 | raw file
1// Copyright (c) 2001-2011 Hartmut Kaiser 2// Copyright (c) 2011 Thomas Heller 3// 4// Distributed under the Boost Software License, Version 1.0. (See accompanying 5// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) 6 7#if !defined(BOOST_SPIRIT_LEX_ARGUMENT_PHEONIX_MARCH_25_2011_1841PM) 8#define BOOST_SPIRIT_LEX_ARGUMENT_PHEONIX_MARCH_25_2011_1841PM 9 10#if defined(_MSC_VER) 11#pragma once 12#endif 13 14#include <boost/spirit/include/phoenix_core.hpp> 15 16namespace boost { namespace spirit { namespace lex 17{ 18 /////////////////////////////////////////////////////////////////////////// 19 // The value_context is used as a noop Phoenix actor to create the 20 // placeholder '_val' (see below). It is a noop actor because it is used 21 // as a placeholder only, while it is being converted either to a 22 // value_getter (if used as a rvalue) or to a value_setter (if used as a 23 // lvalue). The conversion is achieved by specializing and overloading a 24 // couple of the Phoenix templates from the Phoenix expression composition 25 // engine (see the end of this file). 26 struct value_context 27 { 28 typedef mpl::true_ no_nullary; 29 30 typedef unused_type result_type; 31 32 template <typename Env> 33 struct result 34 { 35 typedef unused_type type; 36 }; 37 38 template <typename Env> 39 unused_type 40 eval(Env const& env) const 41 { 42 return unused; 43 } 44 }; 45 46 // forward declarations 47 struct value_getter; 48 template <typename> struct value_setter; 49 50 /////////////////////////////////////////////////////////////////////////// 51 // The state_context is used as a noop Phoenix actor to create the 52 // placeholder '_state' (see below). It is a noop actor because it is used 53 // as a placeholder only, while it is being converted either to a 54 // state_getter (if used as a rvalue) or to a state_setter (if used as a 55 // lvalue). The conversion is achieved by specializing and overloading a 56 // couple of the Phoenix templates from the Phoenix expression composition 57 // engine (see the end of this file). 58 struct state_context 59 { 60 typedef mpl::true_ no_nullary; 61 62 typedef unused_type result_type; 63 64 template <typename Env> 65 struct result 66 { 67 typedef unused_type type; 68 }; 69 70 template <typename Env> 71 unused_type 72 eval(Env const& env) const 73 { 74 return unused; 75 } 76 }; 77 78 // forward declarations 79 struct state_getter; 80 template <typename> struct state_setter; 81 struct eoi_getter; 82}}} 83 84/////////////////////////////////////////////////////////////////////////////// 85#ifdef BOOST_SPIRIT_USE_PHOENIX_V3 86 87BOOST_PHOENIX_DEFINE_EXPRESSION( 88 (boost)(spirit)(lex)(value_setter) 89 , (boost::phoenix::meta_grammar) 90) 91 92BOOST_PHOENIX_DEFINE_EXPRESSION( 93 (boost)(spirit)(lex)(state_setter) 94 , (boost::phoenix::meta_grammar) 95) 96 97namespace boost { namespace phoenix 98{ 99 namespace result_of 100 { 101 template <> 102 struct is_nullary<custom_terminal<boost::spirit::lex::value_context> > 103 : mpl::false_ 104 {}; 105 } 106 107 template <typename Dummy> 108 struct is_custom_terminal<boost::spirit::lex::value_context, Dummy>: mpl::true_ {}; 109 110 template <typename Dummy> 111 struct custom_terminal<boost::spirit::lex::value_context, Dummy> 112 : proto::call< 113 v2_eval( 114 proto::make<boost::spirit::lex::value_getter()> 115 , proto::call<functional::env(proto::_state)> 116 ) 117 > 118 {}; 119 120 template <typename Dummy> 121 struct is_nullary::when<spirit::lex::rule::value_setter, Dummy> 122 : proto::make<mpl::false_()> 123 {}; 124 125 template <typename Dummy> 126 struct default_actions::when<spirit::lex::rule::value_setter, Dummy> 127 : proto::call< 128 v2_eval( 129 proto::make< 130 spirit::lex::value_setter<proto::_child0>( 131 proto::_child0 132 ) 133 > 134 , _env 135 ) 136 > 137 {}; 138 139 template <> 140 struct actor<spirit::lex::value_context> 141 : boost::phoenix::actor<proto::terminal<spirit::lex::value_context>::type> 142 { 143 typedef boost::phoenix::actor< 144 proto::terminal<spirit::lex::value_context>::type 145 > base_type; 146 147 actor(base_type const & base = base_type()) 148 : base_type(base) 149 {} 150 151 template <typename Expr> 152 typename spirit::lex::expression::value_setter< 153 typename phoenix::as_actor<Expr>::type>::type const 154 operator=(Expr const & expr) const 155 { 156 return 157 spirit::lex::expression::value_setter< 158 typename phoenix::as_actor<Expr>::type 159 >::make(phoenix::as_actor<Expr>::convert(expr)); 160 } 161 }; 162 163 namespace result_of 164 { 165 template <> 166 struct is_nullary<custom_terminal<boost::spirit::lex::state_context> > 167 : mpl::false_ 168 {}; 169 } 170 171 template <typename Dummy> 172 struct is_custom_terminal<boost::spirit::lex::state_context, Dummy>: mpl::true_ {}; 173 174 template <typename Dummy> 175 struct custom_terminal<boost::spirit::lex::state_context, Dummy> 176 : proto::call< 177 v2_eval( 178 proto::make<boost::spirit::lex::state_getter()> 179 , proto::call<functional::env(proto::_state)> 180 ) 181 > 182 {}; 183 184 template <typename Dummy> 185 struct is_nullary::when<spirit::lex::rule::state_setter, Dummy> 186 : proto::make<mpl::false_()> 187 {}; 188 189 template <typename Dummy> 190 struct default_actions::when<spirit::lex::rule::state_setter, Dummy> 191 : proto::call< 192 v2_eval( 193 proto::make< 194 spirit::lex::state_setter<proto::_child0>( 195 proto::_child0 196 ) 197 > 198 , _env 199 ) 200 > 201 {}; 202 203 template <> 204 struct actor<spirit::lex::state_context> 205 : boost::phoenix::actor<proto::terminal<spirit::lex::state_context>::type> 206 { 207 typedef boost::phoenix::actor< 208 proto::terminal<spirit::lex::state_context>::type 209 > base_type; 210 211 actor(base_type const & base = base_type()) 212 : base_type(base) 213 {} 214 215 template <typename Expr> 216 typename spirit::lex::expression::state_setter< 217 typename phoenix::as_actor<Expr>::type>::type const 218 operator=(Expr const & expr) const 219 { 220 return 221 spirit::lex::expression::state_setter< 222 typename phoenix::as_actor<Expr>::type 223 >::make(phoenix::as_actor<Expr>::convert(expr)); 224 } 225 }; 226 227 namespace result_of 228 { 229 template <> 230 struct is_nullary<custom_terminal<boost::spirit::lex::eoi_getter> > 231 : mpl::false_ 232 {}; 233 } 234 235 template <typename Dummy> 236 struct is_custom_terminal<boost::spirit::lex::eoi_getter, Dummy>: mpl::true_ {}; 237 238 template <typename Dummy> 239 struct custom_terminal<boost::spirit::lex::eoi_getter, Dummy> 240 : proto::call< 241 v2_eval( 242 proto::make<boost::spirit::lex::eoi_getter()> 243 , proto::call<functional::env(proto::_state)> 244 ) 245 > 246 {}; 247}} 248 249#endif // BOOST_SPIRIT_USE_PHOENIX_V3 250 251#endif