Chris@16: //  Copyright (c) 2001-2011 Hartmut Kaiser
Chris@16: //  Copyright (c) 2001-2011 Joel de Guzman
Chris@16: //  Copyright (c)      2010 Bryce Lelbach
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_JUNE_07_2009_1106AM)
Chris@16: #define BOOST_SPIRIT_LEX_ARGUMENT_JUNE_07_2009_1106AM
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: #include <boost/spirit/include/phoenix_operator.hpp>
Chris@16: #include <boost/spirit/home/support/string_traits.hpp>
Chris@16: #include <boost/spirit/home/lex/argument_phoenix.hpp>
Chris@16: #include <boost/fusion/include/at.hpp>
Chris@16: #include <boost/mpl/at.hpp>
Chris@16: #include <boost/mpl/bool.hpp>
Chris@16: #include <boost/type_traits/is_same.hpp>
Chris@16: #include <boost/type_traits/remove_const.hpp>
Chris@16: #include <boost/type_traits/remove_reference.hpp>
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: namespace boost { namespace spirit { namespace lex
Chris@16: {
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16:     //  The state_getter is a Phoenix actor used to access the name of the 
Chris@16:     //  current lexer state by calling get_state_name() on the context (which 
Chris@16:     //  is the 5th parameter to any lexer semantic actions).
Chris@16:     //
Chris@16:     //  This Phoenix actor is invoked whenever the placeholder '_state' is used
Chris@16:     //  as a rvalue inside a lexer semantic action:
Chris@16:     //
Chris@16:     //      lex::token_def<> identifier = "[a-zA-Z_][a-zA-Z0-9_]*";
Chris@16:     //      this->self = identifier [ std::cout << _state ];
Chris@16:     //
Chris@16:     //  The example shows how to print the lexer state after matching a token
Chris@16:     //  'identifier'.
Chris@16:     struct state_getter
Chris@16:     {
Chris@16:         typedef mpl::true_ no_nullary;
Chris@16: 
Chris@16:         template <typename Env>
Chris@16:         struct result
Chris@16:         {
Chris@16:             typedef
Chris@16:                 typename remove_reference<
Chris@16:                    typename remove_const<
Chris@16:                         typename mpl::at_c<typename Env::args_type, 4>::type
Chris@16:                     >::type
Chris@16:                 >::type
Chris@16:             context_type;
Chris@16: 
Chris@16:             typedef typename context_type::state_name_type type;
Chris@16:         };
Chris@16: 
Chris@16:         template <typename Env>
Chris@16:         typename result<Env>::type
Chris@16:         eval(Env const& env) const
Chris@16:         {
Chris@16:             return fusion::at_c<4>(env.args()).get_state_name();
Chris@16:         }
Chris@16:     };
Chris@16: 
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16:     //  The state_setter is a Phoenix actor used to change the name of the 
Chris@16:     //  current lexer state by calling set_state_name() on the context (which 
Chris@16:     //  is the 5th parameter to any lexer semantic actions).
Chris@16:     //
Chris@16:     //  This Phoenix actor is invoked whenever the placeholder '_state' is used
Chris@16:     //  as a lvalue inside a lexer semantic action:
Chris@16:     //
Chris@16:     //      lex::token_def<> identifier = "[a-zA-Z_][a-zA-Z0-9_]*";
Chris@16:     //      this->self = identifier [ _state = "SOME_LEXER_STATE" ];
Chris@16:     //
Chris@16:     //  The example shows how to change the lexer state after matching a token
Chris@16:     //  'identifier'.
Chris@16:     template <typename Actor>
Chris@16:     struct state_setter
Chris@16:     {
Chris@16:         typedef mpl::true_ no_nullary;
Chris@16: 
Chris@16:         template <typename Env>
Chris@16:         struct result
Chris@16:         {
Chris@16:             typedef void type;
Chris@16:         };
Chris@16: 
Chris@16:         template <typename Env>
Chris@16:         void eval(Env const& env) const
Chris@16:         {
Chris@16:             typedef
Chris@16:                 typename remove_reference<
Chris@16:                    typename remove_const<
Chris@16:                         typename mpl::at_c<typename Env::args_type, 4>::type
Chris@16:                     >::type
Chris@16:                 >::type
Chris@16:             context_type;
Chris@16: 
Chris@16:             typedef typename context_type::state_name_type string;
Chris@16: 
Chris@16:             fusion::at_c<4>(env.args()).set_state_name(
Chris@16:                 traits::get_c_string(actor_.eval(env)));
Chris@16:         }
Chris@16: 
Chris@16:         state_setter(Actor const& actor)
Chris@16:           : actor_(actor) {}
Chris@16: 
Chris@16:         Actor actor_;
Chris@16:     };
Chris@16: 
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16:     //  The value_getter is used to create the _val placeholder, which is a 
Chris@16:     //  Phoenix actor used to access the value of the current token.
Chris@16:     //
Chris@16:     //  This Phoenix actor is invoked whenever the placeholder '_val' is used
Chris@16:     //  as a rvalue inside a lexer semantic action:
Chris@16:     //
Chris@16:     //      lex::token_def<> identifier = "[a-zA-Z_][a-zA-Z0-9_]*";
Chris@16:     //      this->self = identifier [ std::cout << _val ];
Chris@16:     //
Chris@16:     //  The example shows how to use _val to print the identifier name (which
Chris@16:     //  is the initial token value).
Chris@16:     struct value_getter
Chris@16:     {
Chris@16:         typedef mpl::true_ no_nullary;
Chris@16: 
Chris@16:         template <typename Env>
Chris@16:         struct result
Chris@16:         {
Chris@16:             typedef
Chris@16:                 typename remove_reference<
Chris@16:                    typename remove_const<
Chris@16:                         typename mpl::at_c<typename Env::args_type, 4>::type
Chris@16:                     >::type
Chris@16:                 >::type
Chris@16:             context_type;
Chris@16: 
Chris@16:             typedef typename context_type::get_value_type type;
Chris@16:         };
Chris@16: 
Chris@16:         template <typename Env>
Chris@16:         typename result<Env>::type 
Chris@16:         eval(Env const& env) const
Chris@16:         {
Chris@16:             return fusion::at_c<4>(env.args()).get_value();
Chris@16:         }
Chris@16:     };
Chris@16: 
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16:     //  The value_setter is a Phoenix actor used to change the name of the 
Chris@16:     //  current lexer state by calling set_state_name() on the context (which 
Chris@16:     //  is the 5th parameter to any lexer semantic actions).
Chris@16:     //
Chris@16:     //  This Phoenix actor is invoked whenever the placeholder '_val' is used
Chris@16:     //  as a lvalue inside a lexer semantic action:
Chris@16:     //
Chris@16:     //      lex::token_def<> identifier = "[a-zA-Z_][a-zA-Z0-9_]*";
Chris@16:     //      this->self = identifier [ _val = "identifier" ];
Chris@16:     //
Chris@16:     //  The example shows how to change the token value after matching a token
Chris@16:     //  'identifier'.
Chris@16:     template <typename Actor>
Chris@16:     struct value_setter
Chris@16:     {
Chris@16:         typedef mpl::true_ no_nullary;
Chris@16: 
Chris@16:         template <typename Env>
Chris@16:         struct result
Chris@16:         {
Chris@16:             typedef void type;
Chris@16:         };
Chris@16: 
Chris@16:         template <typename Env>
Chris@16:         void eval(Env const& env) const
Chris@16:         {
Chris@16:             fusion::at_c<4>(env.args()).set_value(actor_.eval(env));
Chris@16:         }
Chris@16: 
Chris@16:         value_setter(Actor const& actor)
Chris@16:           : actor_(actor) {}
Chris@16: 
Chris@16:         Actor actor_;
Chris@16:     };
Chris@16: 
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16:     //  The eoi_getter is used to create the _eoi placeholder, which is a 
Chris@16:     //  Phoenix actor used to access the end of input iterator pointing to the 
Chris@16:     //  end of the underlying input sequence.
Chris@16:     //
Chris@16:     //  This actor is invoked whenever the placeholder '_eoi' is used in a
Chris@16:     //  lexer semantic action:
Chris@16:     //
Chris@16:     //      lex::token_def<> identifier = "[a-zA-Z_][a-zA-Z0-9_]*";
Chris@16:     //      this->self = identifier 
Chris@16:     //          [ std::cout << construct_<std::string>(_end, _eoi) ];
Chris@16:     //
Chris@16:     //  The example shows how to use _eoi to print all remaining input after
Chris@16:     //  matching a token 'identifier'.
Chris@16:     struct eoi_getter
Chris@16:     {
Chris@16:         typedef mpl::true_ no_nullary;
Chris@16: 
Chris@16:         template <typename Env>
Chris@16:         struct result
Chris@16:         {
Chris@16:             typedef
Chris@16:                 typename remove_reference<
Chris@16:                    typename remove_const<
Chris@16:                         typename mpl::at_c<typename Env::args_type, 4>::type
Chris@16:                     >::type
Chris@16:                 >::type
Chris@16:             context_type;
Chris@16: 
Chris@16:             typedef typename context_type::base_iterator_type const& type;
Chris@16:         };
Chris@16: 
Chris@16:         template <typename Env>
Chris@16:         typename result<Env>::type 
Chris@16:         eval(Env const& env) const
Chris@16:         {
Chris@16:             return fusion::at_c<4>(env.args()).get_eoi();
Chris@16:         }
Chris@16:     };
Chris@16: 
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16:     // '_start' and '_end' may be used to access the start and the end of 
Chris@16:     // the matched sequence of the current token
Chris@16:     typedef phoenix::arg_names::_1_type _start_type;
Chris@16:     typedef phoenix::arg_names::_2_type _end_type;
Chris@16: #ifndef BOOST_SPIRIT_NO_PREDEFINED_TERMINALS
Chris@16:     _start_type const _start = _start_type();
Chris@16:     _end_type const _end = _end_type();
Chris@16: #endif
Chris@16: 
Chris@16:     // We are reusing the placeholder '_pass' to access and change the pass
Chris@16:     // status of the current match (see support/argument.hpp for its 
Chris@16:     // definition).
Chris@16:     // typedef phoenix::arg_names::_3_type _pass_type;
Chris@16:     using boost::spirit::_pass_type;
Chris@16: #ifndef BOOST_SPIRIT_NO_PREDEFINED_TERMINALS
Chris@16:     using boost::spirit::_pass;
Chris@16: #endif
Chris@16: 
Chris@16:     // '_tokenid' may be used to access and change the tokenid of the current 
Chris@16:     // token
Chris@16:     typedef phoenix::arg_names::_4_type _tokenid_type;
Chris@16: #ifndef BOOST_SPIRIT_NO_PREDEFINED_TERMINALS
Chris@16:     _tokenid_type const _tokenid = _tokenid_type();
Chris@16: #endif
Chris@16: 
Chris@16:     typedef phoenix::actor<value_context> _val_type;
Chris@16:     typedef phoenix::actor<state_context> _state_type;
Chris@16:     typedef phoenix::actor<eoi_getter> _eoi_type;
Chris@16: #ifndef BOOST_SPIRIT_NO_PREDEFINED_TERMINALS
Chris@16:     // '_val' may be used to access and change the token value of the current
Chris@16:     // token
Chris@16:     _val_type const _val = _val_type();
Chris@16:     // _state may be used to access and change the name of the current lexer 
Chris@16:     // state
Chris@16:     _state_type const _state = _state_type();
Chris@16:     // '_eoi' may be used to access the end of input iterator of the input 
Chris@16:     // stream used by the lexer to match tokens from
Chris@16:     _eoi_type const _eoi = _eoi_type();
Chris@16: #endif
Chris@16: }}}
Chris@16: 
Chris@16: 
Chris@16: #undef SPIRIT_DECLARE_ARG
Chris@16: #endif
Chris@16: