1/*=============================================================================
2 Copyright (c) 2001-2011 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#if !defined(BOOST_SPIRIT_PARSER_BINDER_DECEMBER_05_2008_0516_PM)
8#define BOOST_SPIRIT_PARSER_BINDER_DECEMBER_05_2008_0516_PM
9
10#if defined(_MSC_VER)
11#pragma once
12#endif
13
14#include <boost/fusion/include/at.hpp>
15#include <boost/mpl/bool.hpp>
16#include <boost/spirit/home/support/has_semantic_action.hpp>
17
18namespace boost { namespace spirit { namespace qi { namespace detail
19{
20 // parser_binder for plain rules
21 template <typename Parser, typename Auto>
22 struct parser_binder
23 {
24 parser_binder(Parser const& p_)
25 : p(p_) {}
26
27 template <typename Iterator, typename Skipper, typename Context>
28 bool call(Iterator& first, Iterator const& last
29 , Context& context, Skipper const& skipper, mpl::true_) const
30 {
31 // If DeducedAuto is false (semantic actions is present), the
32 // component's attribute is unused.
33 return p.parse(first, last, context, skipper, unused);
34 }
35
36 template <typename Iterator, typename Skipper, typename Context>
37 bool call(Iterator& first, Iterator const& last
38 , Context& context, Skipper const& skipper, mpl::false_) const
39 {
40 // If DeducedAuto is true (no semantic action), we pass the rule's
41 // attribute on to the component.
42 return p.parse(first, last, context, skipper
43 , fusion::at_c<0>(context.attributes));
44 }
45
46 template <typename Iterator, typename Skipper, typename Context>
47 bool operator()(
48 Iterator& first, Iterator const& last
49 , Context& context, Skipper const& skipper) const
50 {
51 // If Auto is false, we need to deduce whether to apply auto rule
52 typedef typename traits::has_semantic_action<Parser>::type auto_rule;
53 return call(first, last, context, skipper, auto_rule());
54 }
55
56 Parser p;
57 };
58
59 // parser_binder for auto rules
60 template <typename Parser>
61 struct parser_binder<Parser, mpl::true_>
62 {
63 parser_binder(Parser const& p_)
64 : p(p_) {}
65
66 template <typename Iterator, typename Skipper, typename Context>
67 bool operator()(
68 Iterator& first, Iterator const& last
69 , Context& context, Skipper const& skipper) const
70 {
71 // If Auto is true, we pass the rule's attribute on to the component.
72 return p.parse(first, last, context, skipper
73 , fusion::at_c<0>(context.attributes));
74 }
75
76 Parser p;
77 };
78
79 template <typename Auto, typename Parser>
80 inline parser_binder<Parser, Auto>
81 bind_parser(Parser const& p)
82 {
83 return parser_binder<Parser, Auto>(p);
84 }
85}}}}
86
87#endif
88