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_POSITIVE_HPP)
11#define BOOST_SPIRIT_POSITIVE_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
19namespace boost { namespace spirit {
20
21BOOST_SPIRIT_CLASSIC_NAMESPACE_BEGIN
22
23 ///////////////////////////////////////////////////////////////////////////
24 //
25 // positive 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 one (1) or more times.
33 //
34 ///////////////////////////////////////////////////////////////////////////
35 struct positive_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 positive
44 : public unary<S, parser<positive<S> > >
45 {
46 typedef positive<S> self_t;
47 typedef unary_parser_category parser_category_t;
48 typedef positive_parser_gen parser_generator_t;
49 typedef unary<S, parser<self_t> > base_t;
50
51 positive(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 = this->subject().parse(scan);
61
62 if (hit)
63 {
64 for (;;)
65 {
66 iterator_t save = scan.first;
67 if (result_t next = this->subject().parse(scan))
68 {
69 scan.concat_match(hit, next);
70 }
71 else
72 {
73 scan.first = save;
74 break;
75 }
76 }
77 }
78 return hit;
79 }
80 };
81
82#if BOOST_WORKAROUND(BOOST_MSVC, >= 1400)
83#pragma warning(pop)
84#endif
85
86 struct positive_parser_gen
87 {
88 template <typename S>
89 struct result
90 {
91 typedef positive<S> type;
92 };
93
94 template <typename S>
95 static positive<S>
96 generate(parser<S> const& a)
97 {
98 return positive<S>(a.derived());
99 }
100 };
101
102 template <typename S>
103 inline positive<S>
104 operator+(parser<S> const& a);
105
106BOOST_SPIRIT_CLASSIC_NAMESPACE_END
107
108}} // namespace BOOST_SPIRIT_CLASSIC_NS
109
110#endif
111
112#include <boost/spirit/home/classic/core/composite/impl/positive.ipp>
113

source code of boost/libs/spirit/include/boost/spirit/home/classic/core/composite/positive.hpp