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The C and C++ Include Header Files
/usr/include/c++/13/bits/regex_executor.h
$ cat -n /usr/include/c++/13/bits/regex_executor.h 1 // class template regex -*- C++ -*- 2 3 // Copyright (C) 2013-2023 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 33 namespace std _GLIBCXX_VISIBILITY(default) 34 { 35 _GLIBCXX_BEGIN_NAMESPACE_VERSION 36 37 namespace __detail 38 { 39 /** 40 * @addtogroup regex-detail 41 * @{ 42 */ 43 44 /** 45 * @brief Takes a regex and an input string and does the matching. 46 * 47 * The %_Executor class has two modes: DFS mode and BFS mode, controlled 48 * by the template parameter %__dfs_mode. 49 */ 50 template<typename _BiIter, typename _Alloc, typename _TraitsT, 51 bool __dfs_mode> 52 class _Executor 53 { 54 using __search_mode = integral_constant<bool, __dfs_mode>; 55 using __dfs = true_type; 56 using __bfs = false_type; 57 58 enum class _Match_mode : unsigned char { _Exact, _Prefix }; 59 60 public: 61 typedef typename iterator_traits<_BiIter>::value_type _CharT; 62 typedef basic_regex<_CharT, _TraitsT> _RegexT; 63 typedef _GLIBCXX_STD_C::vector<sub_match<_BiIter>, _Alloc> _ResultsVec; 64 typedef regex_constants::match_flag_type _FlagT; 65 typedef typename _TraitsT::char_class_type _ClassT; 66 typedef _NFA<_TraitsT> _NFAT; 67 68 public: 69 _Executor(_BiIter __begin, 70 _BiIter __end, 71 _ResultsVec& __results, 72 const _RegexT& __re, 73 _FlagT __flags) 74 : _M_cur_results(__results.get_allocator()), 75 _M_begin(__begin), 76 _M_end(__end), 77 _M_re(__re), 78 _M_nfa(*__re._M_automaton), 79 _M_results(__results), 80 _M_rep_count(_M_nfa.size()), 81 _M_states(_M_nfa._M_start(), _M_nfa.size()), 82 _M_flags(__flags) 83 { 84 using namespace regex_constants; 85 if (__flags & match_prev_avail) // ignore not_bol and not_bow 86 _M_flags &= ~(match_not_bol | match_not_bow); 87 } 88 89 // Set matched when string exactly matches the pattern. 90 bool 91 _M_match() 92 { 93 _M_current = _M_begin; 94 return _M_main(_Match_mode::_Exact); 95 } 96 97 // Set matched when some prefix of the string matches the pattern. 98 bool 99 _M_search_from_first() 100 { 101 _M_current = _M_begin; 102 return _M_main(_Match_mode::_Prefix); 103 } 104 105 bool 106 _M_search(); 107 108 private: 109 void 110 _M_rep_once_more(_Match_mode __match_mode, _StateIdT); 111 112 void 113 _M_handle_repeat(_Match_mode, _StateIdT); 114 115 void 116 _M_handle_subexpr_begin(_Match_mode, _StateIdT); 117 118 void 119 _M_handle_subexpr_end(_Match_mode, _StateIdT); 120 121 void 122 _M_handle_line_begin_assertion(_Match_mode, _StateIdT); 123 124 void 125 _M_handle_line_end_assertion(_Match_mode, _StateIdT); 126 127 void 128 _M_handle_word_boundary(_Match_mode, _StateIdT); 129 130 void 131 _M_handle_subexpr_lookahead(_Match_mode, _StateIdT); 132 133 void 134 _M_handle_match(_Match_mode, _StateIdT); 135 136 void 137 _M_handle_backref(_Match_mode, _StateIdT); 138 139 void 140 _M_handle_accept(_Match_mode, _StateIdT); 141 142 void 143 _M_handle_alternative(_Match_mode, _StateIdT); 144 145 void 146 _M_dfs(_Match_mode __match_mode, _StateIdT __start); 147 148 bool 149 _M_main(_Match_mode __match_mode) 150 { return _M_main_dispatch(__match_mode, __search_mode{}); } 151 152 bool 153 _M_main_dispatch(_Match_mode __match_mode, __dfs); 154 155 bool 156 _M_main_dispatch(_Match_mode __match_mode, __bfs); 157 158 bool 159 _M_is_word(_CharT __ch) const 160 { 161 static const _CharT __s[2] = { 'w' }; 162 return _M_re._M_automaton->_M_traits.isctype 163 (__ch, _M_re._M_automaton->_M_traits.lookup_classname(__s, __s+1)); 164 } 165 166 bool 167 _M_at_begin() const 168 { 169 if (_M_current == _M_begin) 170 { 171 // match_not_bol means ^ does not match [_M_begin,_M_begin) 172 if (_M_flags & regex_constants::match_not_bol) 173 return false; 174 // match_prev_avail means _M_begin is not the start of the input. 175 if (_M_flags & regex_constants::match_prev_avail) 176 { 177 // For ECMAScript multiline matches, check if the previous 178 // character is a line terminator. 179 if (_M_match_multiline()) 180 return _M_is_line_terminator(*std::prev(_M_current)); 181 else 182 return false; 183 } 184 else // ^ matches at _M_begin 185 return true; 186 } 187 else if (_M_match_multiline()) 188 return _M_is_line_terminator(*std::prev(_M_current)); 189 else 190 return false; 191 } 192 193 bool 194 _M_at_end() const 195 { 196 if (_M_current == _M_end) 197 return !(_M_flags & regex_constants::match_not_eol); 198 else if (_M_match_multiline()) 199 return _M_is_line_terminator(*_M_current); 200 else 201 return false; 202 } 203 204 bool 205 _M_word_boundary() const; 206 207 bool 208 _M_lookahead(_StateIdT __next); 209 210 bool 211 _M_is_line_terminator(_CharT __c) const 212 { 213 const auto& __traits = _M_re._M_automaton->_M_traits; 214 const auto& __ct = use_facet<ctype<_CharT>>(__traits.getloc()); 215 const char __n{ __ct.narrow(__c, ' ') }; 216 if (__n == '\n') 217 return true; 218 if (_M_re._M_automaton->_M_options() & regex_constants::ECMAScript) 219 { 220 if (__n == '\r') 221 return true; 222 // FIXME: U+2028 (line separator) and U+2029 (paragraph separator) 223 } 224 return false; 225 } 226 227 bool 228 _M_match_multiline() const noexcept 229 { 230 constexpr auto __m 231 = regex_constants::ECMAScript | regex_constants::__multiline; 232 return (_M_re._M_automaton->_M_options() & __m) == __m; 233 } 234 235 // Holds additional information used in BFS-mode. 236 template<typename _SearchMode, typename _ResultsVec> 237 struct _State_info; 238 239 template<typename _ResultsVec> 240 struct _State_info<__bfs, _ResultsVec> 241 { 242 explicit 243 _State_info(_StateIdT __start, size_t __n) 244 : _M_visited_states(new bool[__n]()), _M_start(__start) 245 { } 246 247 ~_State_info() { delete[] _M_visited_states; } 248 249 _State_info(const _State_info&) = delete; 250 _State_info& operator=(const _State_info&) = delete; 251 252 bool _M_visited(_StateIdT __i) 253 { 254 if (_M_visited_states[__i]) 255 return true; 256 _M_visited_states[__i] = true; 257 return false; 258 } 259 260 void _M_queue(_StateIdT __i, const _ResultsVec& __res) 261 { _M_match_queue.emplace_back(__i, __res); } 262 263 // Dummy implementations for BFS mode. 264 _BiIter* _M_get_sol_pos() { return nullptr; } 265 266 // Saves states that need to be considered for the next character. 267 _GLIBCXX_STD_C::vector<pair<_StateIdT, _ResultsVec>> _M_match_queue; 268 // Indicates which states are already visited. 269 bool* _M_visited_states; 270 // To record current solution. 271 _StateIdT _M_start; 272 }; 273 274 template<typename _ResultsVec> 275 struct _State_info<__dfs, _ResultsVec> 276 { 277 explicit 278 _State_info(_StateIdT __start, size_t) : _M_start(__start) 279 { } 280 281 // Dummy implementations for DFS mode. 282 bool _M_visited(_StateIdT) const { return false; } 283 void _M_queue(_StateIdT, const _ResultsVec&) { } 284 285 _BiIter* _M_get_sol_pos() { return &_M_sol_pos; } 286 287 // To record current solution. 288 _StateIdT _M_start; 289 _BiIter _M_sol_pos; 290 }; 291 292 public: 293 _ResultsVec _M_cur_results; 294 _BiIter _M_current; 295 _BiIter _M_begin; 296 const _BiIter _M_end; 297 const _RegexT& _M_re; 298 const _NFAT& _M_nfa; 299 _ResultsVec& _M_results; 300 _GLIBCXX_STD_C::vector<pair<_BiIter, int>> _M_rep_count; 301 _State_info<__search_mode, _ResultsVec> _M_states; 302 _FlagT _M_flags; 303 // Do we have a solution so far? 304 bool _M_has_sol; 305 }; 306 307 ///@} regex-detail 308 } // namespace __detail 309 _GLIBCXX_END_NAMESPACE_VERSION 310 } // namespace std 311 312 #include <bits/regex_executor.tcc>
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