1 // class template regex -*- C++ -*- 2 3 // Copyright (C) 2013-2024 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_scanner.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 namespace std _GLIBCXX_VISIBILITY(default) 32 { 33 _GLIBCXX_BEGIN_NAMESPACE_VERSION 34 35 namespace __detail 36 { 37 /** 38 * @addtogroup regex-detail 39 * @{ 40 */ 41 42 struct _ScannerBase 43 { 44 public: 45 /// Token types returned from the scanner. 46 enum _TokenT : unsigned 47 { 48 _S_token_anychar, 49 _S_token_ord_char, 50 _S_token_oct_num, 51 _S_token_hex_num, 52 _S_token_backref, 53 _S_token_subexpr_begin, 54 _S_token_subexpr_no_group_begin, 55 _S_token_subexpr_lookahead_begin, // neg if _M_value[0] == 'n' 56 _S_token_subexpr_end, 57 _S_token_bracket_begin, 58 _S_token_bracket_neg_begin, 59 _S_token_bracket_end, 60 _S_token_interval_begin, 61 _S_token_interval_end, 62 _S_token_quoted_class, 63 _S_token_char_class_name, 64 _S_token_collsymbol, 65 _S_token_equiv_class_name, 66 _S_token_opt, 67 _S_token_or, 68 _S_token_closure0, 69 _S_token_closure1, 70 _S_token_line_begin, 71 _S_token_line_end, 72 _S_token_word_bound, // neg if _M_value[0] == 'n' 73 _S_token_comma, 74 _S_token_dup_count, 75 _S_token_eof, 76 _S_token_bracket_dash, 77 _S_token_unknown = -1u 78 }; 79 80 protected: 81 typedef regex_constants::syntax_option_type _FlagT; 82 83 enum _StateT 84 { 85 _S_state_normal, 86 _S_state_in_brace, 87 _S_state_in_bracket, 88 }; 89 90 protected: 91 _ScannerBase(_FlagT __flags) 92 : _M_state(_S_state_normal), 93 _M_flags(__flags), 94 _M_escape_tbl(_M_is_ecma() 95 ? _M_ecma_escape_tbl 96 : _M_awk_escape_tbl), 97 _M_spec_char(_M_is_ecma() 98 ? _M_ecma_spec_char 99 : _M_flags & regex_constants::basic 100 ? _M_basic_spec_char 101 : _M_flags & regex_constants::extended 102 ? _M_extended_spec_char 103 : _M_flags & regex_constants::grep 104 ? ".[\\*^$\n" 105 : _M_flags & regex_constants::egrep 106 ? ".[\\()*+?{|^$\n" 107 : _M_flags & regex_constants::awk 108 ? _M_extended_spec_char 109 : nullptr), 110 _M_at_bracket_start(false) 111 { __glibcxx_assert(_M_spec_char); } 112 113 protected: 114 const char* 115 _M_find_escape(char __c) 116 { 117 auto __it = _M_escape_tbl; 118 for (; __it->first != '\0'; ++__it) 119 if (__it->first == __c) 120 return &__it->second; 121 return nullptr; 122 } 123 124 bool 125 _M_is_ecma() const 126 { return _M_flags & regex_constants::ECMAScript; } 127 128 bool 129 _M_is_basic() const 130 { return _M_flags & (regex_constants::basic | regex_constants::grep); } 131 132 bool 133 _M_is_extended() const 134 { 135 return _M_flags & (regex_constants::extended 136 | regex_constants::egrep 137 | regex_constants::awk); 138 } 139 140 bool 141 _M_is_grep() const 142 { return _M_flags & (regex_constants::grep | regex_constants::egrep); } 143 144 bool 145 _M_is_awk() const 146 { return _M_flags & regex_constants::awk; } 147 148 protected: 149 // TODO: Make them static in the next abi change. 150 const std::pair<char, _TokenT> _M_token_tbl[9] = 151 { 152 {'^', _S_token_line_begin}, 153 {'$', _S_token_line_end}, 154 {'.', _S_token_anychar}, 155 {'*', _S_token_closure0}, 156 {'+', _S_token_closure1}, 157 {'?', _S_token_opt}, 158 {'|', _S_token_or}, 159 {'\n', _S_token_or}, // grep and egrep 160 {'\0', _S_token_or}, 161 }; 162 const std::pair<char, char> _M_ecma_escape_tbl[8] = 163 { 164 {'0', '\0'}, 165 {'b', '\b'}, 166 {'f', '\f'}, 167 {'n', '\n'}, 168 {'r', '\r'}, 169 {'t', '\t'}, 170 {'v', '\v'}, 171 {'\0', '\0'}, 172 }; 173 const std::pair<char, char> _M_awk_escape_tbl[11] = 174 { 175 {'"', '"'}, 176 {'/', '/'}, 177 {'\\', '\\'}, 178 {'a', '\a'}, 179 {'b', '\b'}, 180 {'f', '\f'}, 181 {'n', '\n'}, 182 {'r', '\r'}, 183 {'t', '\t'}, 184 {'v', '\v'}, 185 {'\0', '\0'}, 186 }; 187 const char* _M_ecma_spec_char = "^$\\.*+?()[]{}|"; 188 const char* _M_basic_spec_char = ".[\\*^$"; 189 const char* _M_extended_spec_char = ".[\\()*+?{|^$"; 190 191 _StateT _M_state; 192 _FlagT _M_flags; 193 _TokenT _M_token; 194 const std::pair<char, char>* _M_escape_tbl; 195 const char* _M_spec_char; 196 bool _M_at_bracket_start; 197 }; 198 199 /** 200 * @brief Scans an input range for regex tokens. 201 * 202 * The %_Scanner class interprets the regular expression pattern in 203 * the input range passed to its constructor as a sequence of parse 204 * tokens passed to the regular expression compiler. The sequence 205 * of tokens provided depends on the flag settings passed to the 206 * constructor: different regular expression grammars will interpret 207 * the same input pattern in syntactically different ways. 208 */ 209 template<typename _CharT> 210 class _Scanner 211 : public _ScannerBase 212 { 213 public: 214 typedef std::basic_string<_CharT> _StringT; 215 typedef regex_constants::syntax_option_type _FlagT; 216 typedef const std::ctype<_CharT> _CtypeT; 217 218 _Scanner(const _CharT* __begin, const _CharT* __end, 219 _FlagT __flags, std::locale __loc); 220 221 void 222 _M_advance(); 223 224 _TokenT 225 _M_get_token() const noexcept 226 { return _M_token; } 227 228 const _StringT& 229 _M_get_value() const noexcept 230 { return _M_value; } 231 232 #ifdef _GLIBCXX_DEBUG 233 std::ostream& 234 _M_print(std::ostream&); 235 #endif 236 237 private: 238 void 239 _M_scan_normal(); 240 241 void 242 _M_scan_in_bracket(); 243 244 void 245 _M_scan_in_brace(); 246 247 void 248 _M_eat_escape_ecma(); 249 250 void 251 _M_eat_escape_posix(); 252 253 void 254 _M_eat_escape_awk(); 255 256 void 257 _M_eat_class(char); 258 259 const _CharT* _M_current; 260 const _CharT* _M_end; 261 _CtypeT& _M_ctype; 262 _StringT _M_value; 263 void (_Scanner::* _M_eat_escape)(); 264 }; 265 266 ///@} regex-detail 267 } // namespace __detail 268 _GLIBCXX_END_NAMESPACE_VERSION 269 } // namespace std 270 271 #include <bits/regex_scanner.tcc> 272
Indexes created Mon Mar 02 05:31:46 UTC 2026