1 // class template regex -*- C++ -*- 2 3 // Copyright (C) 2013-2015 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 namespace __detail 34 { 35 _GLIBCXX_BEGIN_NAMESPACE_VERSION 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 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_unknown 77 }; 78 79 protected: 80 typedef regex_constants::syntax_option_type _FlagT; 81 82 enum _StateT 83 { 84 _S_state_normal, 85 _S_state_in_brace, 86 _S_state_in_bracket, 87 }; 88 89 protected: 90 _ScannerBase(_FlagT __flags) 91 : _M_state(_S_state_normal), 92 _M_flags(__flags), 93 _M_escape_tbl(_M_is_ecma() 94 ? _M_ecma_escape_tbl 95 : _M_awk_escape_tbl), 96 _M_spec_char(_M_is_ecma() 97 ? _M_ecma_spec_char 98 : _M_is_basic() 99 ? _M_basic_spec_char 100 : _M_extended_spec_char), 101 _M_at_bracket_start(false) 102 { } 103 104 protected: 105 const char* 106 _M_find_escape(char __c) 107 { 108 auto __it = _M_escape_tbl; 109 for (; __it->first != '\0'; ++__it) 110 if (__it->first == __c) 111 return &__it->second; 112 return nullptr; 113 } 114 115 bool 116 _M_is_ecma() const 117 { return _M_flags & regex_constants::ECMAScript; } 118 119 bool 120 _M_is_basic() const 121 { return _M_flags & (regex_constants::basic | regex_constants::grep); } 122 123 bool 124 _M_is_extended() const 125 { 126 return _M_flags & (regex_constants::extended 127 | regex_constants::egrep 128 | regex_constants::awk); 129 } 130 131 bool 132 _M_is_grep() const 133 { return _M_flags & (regex_constants::grep | regex_constants::egrep); } 134 135 bool 136 _M_is_awk() const 137 { return _M_flags & regex_constants::awk; } 138 139 protected: 140 const std::pair<char, _TokenT> _M_token_tbl[9] = 141 { 142 {'^', _S_token_line_begin}, 143 {'$', _S_token_line_end}, 144 {'.', _S_token_anychar}, 145 {'*', _S_token_closure0}, 146 {'+', _S_token_closure1}, 147 {'?', _S_token_opt}, 148 {'|', _S_token_or}, 149 {'\n', _S_token_or}, // grep and egrep 150 {'\0', _S_token_or}, 151 }; 152 const std::pair<char, char> _M_ecma_escape_tbl[8] = 153 { 154 {'0', '\0'}, 155 {'b', '\b'}, 156 {'f', '\f'}, 157 {'n', '\n'}, 158 {'r', '\r'}, 159 {'t', '\t'}, 160 {'v', '\v'}, 161 {'\0', '\0'}, 162 }; 163 const std::pair<char, char> _M_awk_escape_tbl[11] = 164 { 165 {'"', '"'}, 166 {'/', '/'}, 167 {'\\', '\\'}, 168 {'a', '\a'}, 169 {'b', '\b'}, 170 {'f', '\f'}, 171 {'n', '\n'}, 172 {'r', '\r'}, 173 {'t', '\t'}, 174 {'v', '\v'}, 175 {'\0', '\0'}, 176 }; 177 const char* _M_ecma_spec_char = "^$\\.*+?()[]{}|"; 178 const char* _M_basic_spec_char = ".[\\*^$"; 179 const char* _M_extended_spec_char = ".[\\()*+?{|^$"; 180 181 _StateT _M_state; 182 _FlagT _M_flags; 183 _TokenT _M_token; 184 const std::pair<char, char>* _M_escape_tbl; 185 const char* _M_spec_char; 186 bool _M_at_bracket_start; 187 }; 188 189 /** 190 * @brief Scans an input range for regex tokens. 191 * 192 * The %_Scanner class interprets the regular expression pattern in 193 * the input range passed to its constructor as a sequence of parse 194 * tokens passed to the regular expression compiler. The sequence 195 * of tokens provided depends on the flag settings passed to the 196 * constructor: different regular expression grammars will interpret 197 * the same input pattern in syntactically different ways. 198 */ 199 template<typename _CharT> 200 class _Scanner 201 : public _ScannerBase 202 { 203 public: 204 typedef const _CharT* _IterT; 205 typedef std::basic_string<_CharT> _StringT; 206 typedef regex_constants::syntax_option_type _FlagT; 207 typedef const std::ctype<_CharT> _CtypeT; 208 209 _Scanner(_IterT __begin, _IterT __end, 210 _FlagT __flags, std::locale __loc); 211 212 void 213 _M_advance(); 214 215 _TokenT 216 _M_get_token() const 217 { return _M_token; } 218 219 const _StringT& 220 _M_get_value() const 221 { return _M_value; } 222 223 #ifdef _GLIBCXX_DEBUG 224 std::ostream& 225 _M_print(std::ostream&); 226 #endif 227 228 private: 229 void 230 _M_scan_normal(); 231 232 void 233 _M_scan_in_bracket(); 234 235 void 236 _M_scan_in_brace(); 237 238 void 239 _M_eat_escape_ecma(); 240 241 void 242 _M_eat_escape_posix(); 243 244 void 245 _M_eat_escape_awk(); 246 247 void 248 _M_eat_class(char); 249 250 _IterT _M_current; 251 _IterT _M_end; 252 _CtypeT& _M_ctype; 253 _StringT _M_value; 254 void (_Scanner::* _M_eat_escape)(); 255 }; 256 257 //@} regex-detail 258 _GLIBCXX_END_NAMESPACE_VERSION 259 } // namespace __detail 260 } // namespace std 261 262 #include <bits/regex_scanner.tcc> 263