phoenix/statement/for.hpp

0001 /*==============================================================================
0002     Copyright (c) 2001-2010 Joel de Guzman
0003     Copyright (c) 2010 Thomas Heller
0004
0005     Distributed under the Boost Software License, Version 1.0. (See accompanying
0006     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0007 ==============================================================================*/
0008 #ifndef BOOST_PHOENIX_STATEMENT_FOR_HPP
0009 #define BOOST_PHOENIX_STATEMENT_FOR_HPP
0010
0011 #include <boost/phoenix/core/limits.hpp>
0012 #include <boost/phoenix/core/call.hpp>
0013 #include <boost/phoenix/core/expression.hpp>
0014 #include <boost/phoenix/core/meta_grammar.hpp>
0015
0016 BOOST_PHOENIX_DEFINE_EXPRESSION(
0017     (boost)(phoenix)(for_)
0018   , (meta_grammar) // Cond
0019     (meta_grammar) // Init
0020     (meta_grammar) // Step
0021     (meta_grammar) // Do
0022 )
0023
0024 namespace boost { namespace phoenix
0025 {
0026     struct for_eval
0027     {
0028         typedef void result_type;
0029
0030         template <
0031             typename Init
0032           , typename Cond
0033           , typename Step
0034           , typename Do
0035           , typename Context
0036         >
0037         result_type
0038         operator()(
0039             Init const& init
0040           , Cond const& cond
0041           , Step const& step
0042           , Do const& do_it
0043           , Context const & ctx
0044         ) const
0045         {
0046             for(boost::phoenix::eval(init, ctx); boost::phoenix::eval(cond, ctx); boost::phoenix::eval(step, ctx))
0047                 boost::phoenix::eval(do_it, ctx);
0048         }
0049     };
0050
0051     template <typename Dummy>
0052     struct default_actions::when<rule::for_, Dummy>
0053         : call<for_eval, Dummy>
0054     {};
0055
0056     template <typename Init, typename Cond, typename Step>
0057     struct for_gen
0058     {
0059         for_gen(Init const& init_, Cond const& cond_, Step const& step_)
0060             : init(init_), cond(cond_), step(step_) {}
0061
0062         template <typename Do>
0063         typename expression::for_<Init, Cond, Step, Do>::type const
0064         operator[](Do const& do_it) const
0065         {
0066             return
0067                 expression::
0068                     for_<Init, Cond, Step, Do>::
0069                         make(init, cond, step, do_it);
0070         }
0071
0072         Init init;
0073         Cond cond;
0074         Step step;
0075     };
0076
0077     template <typename Init, typename Cond, typename Step>
0078     inline
0079     for_gen<Init, Cond, Step> const
0080     for_(Init const& init, Cond const& cond, Step const& step)
0081     {
0082         return for_gen<Init, Cond, Step>(init, cond, step);
0083     }
0084
0085 }}
0086
0087 #endif