1 // class template regex -*- C++ -*-
2
3 // Copyright (C) 2013-2014 Free Software Foundation, Inc.
4 //
5 // This file is part of the GNU ISO C++ Library. This library is free
6 // software; you can redistribute it and/or modify it under the
7 // terms of the GNU General Public License as published by the
8 // Free Software Foundation; either version 3, or (at your option)
9 // any later version.
10
11 // This library is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 // GNU General Public License for more details.
15
16 // Under Section 7 of GPL version 3, you are granted additional
17 // permissions described in the GCC Runtime Library Exception, version
18 // 3.1, as published by the Free Software Foundation.
19
20 // You should have received a copy of the GNU General Public License and
21 // a copy of the GCC Runtime Library Exception along with this program;
22 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23 // <http://www.gnu.org/licenses/>.
24
25 /**
26 * @file bits/regex_executor.h
27 * This is an internal header file, included by other library headers.
28 * Do not attempt to use it directly. @headername{regex}
29 */
30
31 // FIXME convert comments to doxygen format.
32
_GLIBCXX_VISIBILITY(default)33 namespace std _GLIBCXX_VISIBILITY(default)
34 {
35 namespace __detail
36 {
37 _GLIBCXX_BEGIN_NAMESPACE_VERSION
38
39 /**
40 * @addtogroup regex-detail
41 * @{
42 */
43
44 /**
45 * @brief Takes a regex and an input string in and
46 * do the matching.
47 *
48 * The %_Executor class has two modes: DFS mode and BFS mode, controlled
49 * by the template parameter %__dfs_mode.
50 */
51 template<typename _BiIter, typename _Alloc, typename _TraitsT,
52 bool __dfs_mode>
53 class _Executor
54 {
55 public:
56 typedef typename iterator_traits<_BiIter>::value_type _CharT;
57 typedef basic_regex<_CharT, _TraitsT> _RegexT;
58 typedef std::vector<sub_match<_BiIter>, _Alloc> _ResultsVec;
59 typedef regex_constants::match_flag_type _FlagT;
60 typedef typename _TraitsT::char_class_type _ClassT;
61 typedef _NFA<_TraitsT> _NFAT;
62
63 public:
64 _Executor(_BiIter __begin,
65 _BiIter __end,
66 _ResultsVec& __results,
67 const _RegexT& __re,
68 _FlagT __flags)
69 : _M_begin(__begin),
70 _M_end(__end),
71 _M_re(__re),
72 _M_nfa(*__re._M_automaton),
73 _M_results(__results),
74 _M_match_queue(__dfs_mode ? nullptr
75 : new vector<pair<_StateIdT, _ResultsVec>>()),
76 _M_visited(__dfs_mode ? nullptr : new vector<bool>(_M_nfa.size())),
77 _M_flags((__flags & regex_constants::match_prev_avail)
78 ? (__flags
79 & ~regex_constants::match_not_bol
80 & ~regex_constants::match_not_bow)
81 : __flags),
82 _M_start_state(_M_nfa._M_start())
83 { }
84
85 // Set matched when string exactly match the pattern.
86 bool
87 _M_match()
88 {
89 _M_current = _M_begin;
90 return _M_main<true>();
91 }
92
93 // Set matched when some prefix of the string matches the pattern.
94 bool
95 _M_search_from_first()
96 {
97 _M_current = _M_begin;
98 return _M_main<false>();
99 }
100
101 bool
102 _M_search();
103
104 private:
105 template<bool __match_mode>
106 void
107 _M_dfs(_StateIdT __start);
108
109 template<bool __match_mode>
110 bool
111 _M_main();
112
113 bool
114 _M_is_word(_CharT __ch) const
115 {
116 static const _CharT __s[2] = { 'w' };
117 return _M_re._M_traits.isctype
118 (__ch, _M_re._M_traits.lookup_classname(__s, __s+1));
119 }
120
121 bool
122 _M_at_begin() const
123 {
124 return _M_current == _M_begin
125 && !(_M_flags & (regex_constants::match_not_bol
126 | regex_constants::match_prev_avail));
127 }
128
129 bool
130 _M_at_end() const
131 {
132 return _M_current == _M_end
133 && !(_M_flags & regex_constants::match_not_eol);
134 }
135
136 bool
137 _M_word_boundary(_State<_TraitsT> __state) const;
138
139 bool
140 _M_lookahead(_State<_TraitsT> __state);
141
142 public:
143 _ResultsVec _M_cur_results;
144 _BiIter _M_current;
145 const _BiIter _M_begin;
146 const _BiIter _M_end;
147 const _RegexT& _M_re;
148 const _NFAT& _M_nfa;
149 _ResultsVec& _M_results;
150 // Used in BFS, saving states that need to be considered for the next
151 // character.
152 std::unique_ptr<vector<pair<_StateIdT, _ResultsVec>>> _M_match_queue;
153 // Used in BFS, indicating that which state is already visited.
154 std::unique_ptr<vector<bool>> _M_visited;
155 _FlagT _M_flags;
156 // To record current solution.
157 _StateIdT _M_start_state;
158 // Do we have a solution so far?
159 bool _M_has_sol;
160 };
161
162 //@} regex-detail
163 _GLIBCXX_END_NAMESPACE_VERSION
164 } // namespace __detail
165 } // namespace std
166
167 #include <bits/regex_executor.tcc>
168