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1 | /*============================================================================= |
2 | Copyright (c) 1998-2003 Joel de Guzman | |
3 | Copyright (c) 2001 Daniel Nuffer | |
4 | Copyright (c) 2002 Hartmut Kaiser | |
5 | http://spirit.sourceforge.net/ | |
6 | ||
7 | Distributed under the Boost Software License, Version 1.0. (See accompanying | |
8 | file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) | |
9 | =============================================================================*/ | |
10 | #if !defined(BOOST_SPIRIT_KLEENE_STAR_HPP) | |
11 | #define BOOST_SPIRIT_KLEENE_STAR_HPP | |
12 | ||
13 | #include <boost/spirit/home/classic/namespace.hpp> | |
14 | #include <boost/spirit/home/classic/core/parser.hpp> | |
15 | #include <boost/spirit/home/classic/core/primitives/primitives.hpp> | |
16 | #include <boost/spirit/home/classic/core/composite/composite.hpp> | |
17 | #include <boost/spirit/home/classic/meta/as_parser.hpp> | |
18 | ||
19 | namespace boost { namespace spirit { | |
20 | ||
21 | BOOST_SPIRIT_CLASSIC_NAMESPACE_BEGIN | |
22 | ||
23 | /////////////////////////////////////////////////////////////////////////// | |
24 | // | |
25 | // kleene_star class | |
26 | // | |
27 | // Handles expressions of the form: | |
28 | // | |
29 | // *a | |
30 | // | |
31 | // where a is a parser. The expression returns a composite | |
32 | // parser that matches its subject zero (0) or more times. | |
33 | // | |
34 | /////////////////////////////////////////////////////////////////////////// | |
35 | struct kleene_star_parser_gen; | |
36 | ||
37 | #if BOOST_WORKAROUND(BOOST_MSVC, >= 1400) | |
38 | #pragma warning(push) | |
39 | #pragma warning(disable:4512) //assignment operator could not be generated | |
40 | #endif | |
41 | ||
42 | template <typename S> | |
43 | struct kleene_star | |
44 | : public unary<S, parser<kleene_star<S> > > | |
45 | { | |
46 | typedef kleene_star<S> self_t; | |
47 | typedef unary_parser_category parser_category_t; | |
48 | typedef kleene_star_parser_gen parser_generator_t; | |
49 | typedef unary<S, parser<self_t> > base_t; | |
50 | ||
51 | kleene_star(S const& a) | |
52 | : base_t(a) {} | |
53 | ||
54 | template <typename ScannerT> | |
55 | typename parser_result<self_t, ScannerT>::type | |
56 | parse(ScannerT const& scan) const | |
57 | { | |
58 | typedef typename parser_result<self_t, ScannerT>::type result_t; | |
59 | typedef typename ScannerT::iterator_t iterator_t; | |
60 | result_t hit = scan.empty_match(); | |
61 | ||
62 | for (;;) | |
63 | { | |
64 | iterator_t save = scan.first; | |
65 | if (result_t next = this->subject().parse(scan)) | |
66 | { | |
67 | scan.concat_match(hit, next); | |
68 | } | |
69 | else | |
70 | { | |
71 | scan.first = save; | |
72 | return hit; | |
73 | } | |
74 | } | |
75 | } | |
76 | }; | |
77 | ||
78 | #if BOOST_WORKAROUND(BOOST_MSVC, >= 1400) | |
79 | #pragma warning(pop) | |
80 | #endif | |
81 | ||
82 | struct kleene_star_parser_gen | |
83 | { | |
84 | template <typename S> | |
85 | struct result | |
86 | { | |
87 | typedef kleene_star<S> type; | |
88 | }; | |
89 | ||
90 | template <typename S> | |
91 | static kleene_star<S> | |
92 | generate(parser<S> const& a) | |
93 | { | |
94 | return kleene_star<S>(a.derived()); | |
95 | } | |
96 | }; | |
97 | ||
98 | ////////////////////////////////// | |
99 | template <typename S> | |
100 | kleene_star<S> | |
101 | operator*(parser<S> const& a); | |
102 | ||
103 | BOOST_SPIRIT_CLASSIC_NAMESPACE_END | |
104 | ||
105 | }} // namespace BOOST_SPIRIT_CLASSIC_NS | |
106 | ||
107 | #endif | |
108 | ||
109 | #include <boost/spirit/home/classic/core/composite/impl/kleene_star.ipp> |