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1 | /*============================================================================= |
2 | Copyright (arg) 2001-2014 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 | =============================================================================*/ | |
11fdf7f2 TL |
7 | #if !defined(BOOST_SPIRIT_X3_ACTION_JANUARY_07_2007_1128AM) |
8 | #define BOOST_SPIRIT_X3_ACTION_JANUARY_07_2007_1128AM | |
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9 | |
10 | #include <boost/spirit/home/x3/support/context.hpp> | |
11 | #include <boost/spirit/home/x3/support/traits/attribute_of.hpp> | |
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12 | #include <boost/spirit/home/x3/core/call.hpp> |
13 | #include <boost/spirit/home/x3/nonterminal/detail/transform_attribute.hpp> | |
14 | #include <boost/range/iterator_range.hpp> | |
15 | ||
16 | namespace boost { namespace spirit { namespace x3 | |
17 | { | |
18 | struct raw_attribute_type; | |
19 | struct parse_pass_context_tag; | |
20 | ||
21 | template <typename Context> | |
22 | inline bool& _pass(Context const& context) | |
23 | { | |
24 | return x3::get<parse_pass_context_tag>(context); | |
25 | } | |
26 | ||
27 | template <typename Subject, typename Action> | |
28 | struct action : unary_parser<Subject, action<Subject, Action>> | |
29 | { | |
30 | typedef unary_parser<Subject, action<Subject, Action>> base_type; | |
31 | static bool const is_pass_through_unary = true; | |
32 | static bool const has_action = true; | |
33 | ||
34 | action(Subject const& subject, Action f) | |
35 | : base_type(subject), f(f) {} | |
36 | ||
37 | template <typename Iterator, typename Context, typename RuleContext, typename Attribute> | |
38 | bool call_action( | |
39 | Iterator& first, Iterator const& last | |
40 | , Context const& context, RuleContext& rcontext, Attribute& attr) const | |
41 | { | |
42 | bool pass = true; | |
43 | auto action_context = make_context<parse_pass_context_tag>(pass, context); | |
44 | call(f, first, last, action_context, rcontext, attr); | |
45 | return pass; | |
46 | } | |
47 | ||
48 | template <typename Iterator, typename Context | |
49 | , typename RuleContext, typename Attribute> | |
50 | bool parse_main(Iterator& first, Iterator const& last | |
51 | , Context const& context, RuleContext& rcontext, Attribute& attr) const | |
52 | { | |
53 | Iterator save = first; | |
54 | if (this->subject.parse(first, last, context, rcontext, attr)) | |
55 | { | |
56 | if (call_action(first, last, context, rcontext, attr)) | |
57 | return true; | |
58 | ||
59 | // reset iterators if semantic action failed the match | |
60 | // retrospectively | |
61 | first = save; | |
62 | } | |
63 | return false; | |
64 | } | |
65 | ||
66 | // attr==raw_attribute_type, action wants iterator_range (see raw.hpp) | |
67 | template <typename Iterator, typename Context, typename RuleContext> | |
68 | bool parse_main(Iterator& first, Iterator const& last | |
69 | , Context const& context, RuleContext& rcontext, raw_attribute_type&) const | |
70 | { | |
71 | boost::iterator_range<Iterator> rng; | |
72 | // synthesize the attribute since one is not supplied | |
73 | return parse_main(first, last, context, rcontext, rng); | |
74 | } | |
75 | ||
76 | // attr==unused, action wants attribute | |
77 | template <typename Iterator, typename Context, typename RuleContext> | |
78 | bool parse(Iterator& first, Iterator const& last | |
79 | , Context const& context, RuleContext& rcontext, unused_type) const | |
80 | { | |
81 | typedef typename | |
82 | traits::attribute_of<action<Subject, Action>, Context>::type | |
83 | attribute_type; | |
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84 | |
85 | // synthesize the attribute since one is not supplied | |
92f5a8d4 | 86 | attribute_type attr{}; |
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87 | return parse_main(first, last, context, rcontext, attr); |
88 | } | |
89 | ||
90 | // main parse function | |
91 | template <typename Iterator, typename Context | |
92 | , typename RuleContext, typename Attribute> | |
93 | bool parse(Iterator& first, Iterator const& last | |
94 | , Context const& context, RuleContext& rcontext, Attribute& attr) const | |
95 | { | |
96 | return parse_main(first, last, context, rcontext, attr); | |
97 | } | |
98 | ||
99 | Action f; | |
100 | }; | |
101 | ||
102 | template <typename P, typename Action> | |
103 | inline action<typename extension::as_parser<P>::value_type, Action> | |
104 | operator/(P const& p, Action f) | |
105 | { | |
106 | return { as_parser(p), f }; | |
107 | } | |
108 | }}} | |
109 | ||
110 | #endif |