/src/contrib/boost/spirit/home/phoenix/statement/for.hpp

 1/*=============================================================================
 2    Copyright (c) 2001-2007 Joel de Guzman
 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#ifndef PHOENIX_STATEMENT_FOR_HPP
 8#define PHOENIX_STATEMENT_FOR_HPP
 9
10#include <boost/spirit/home/phoenix/core/composite.hpp>
11#include <boost/spirit/home/phoenix/core/compose.hpp>
12
13namespace boost { namespace phoenix
14{
15    struct for_eval
16    {
17        template <
18            typename Env
19          , typename Init, typename Cond, typename Step, typename Do>
20        struct result
21        {
22            typedef void type;
23        };
24
25        template <
26            typename RT, typename Env
27          , typename Init, typename Cond, typename Step, typename Do>
28        static void
29        eval(
30            Env const& env
31          , Init& init, Cond& cond, Step& step, Do& do_)
32        {
33            for (init.eval(env); cond.eval(env); step.eval(env))
34                do_.eval(env);
35        }
36    };
37
38    template <typename Init, typename Cond, typename Step>
39    struct for_gen
40    {
41        for_gen(Init const& init, Cond const& cond, Step const& step)
42            : init(init), cond(cond), step(step) {}
43
44        template <typename Do>
45        actor<typename as_composite<for_eval, Init, Cond, Step, Do>::type>
46        operator[](Do const& do_) const
47        {
48            return compose<for_eval>(init, cond, step, do_);
49        }
50
51        Init init;
52        Cond cond;
53        Step step;
54    };
55
56    template <typename Init, typename Cond, typename Step>
57    inline for_gen<Init, Cond, Step>
58    for_(Init const& init, Cond const& cond, Step const& step)
59    {
60        return for_gen<Init, Cond, Step>(init, cond, step);
61    }
62}}
63
64#endif