libstdc++
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00001 // class template regex -*- C++ -*- 00002 00003 // Copyright (C) 2013-2017 Free Software Foundation, Inc. 00004 // 00005 // This file is part of the GNU ISO C++ Library. This library is free 00006 // software; you can redistribute it and/or modify it under the 00007 // terms of the GNU General Public License as published by the 00008 // Free Software Foundation; either version 3, or (at your option) 00009 // any later version. 00010 00011 // This library is distributed in the hope that it will be useful, 00012 // but WITHOUT ANY WARRANTY; without even the implied warranty of 00013 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00014 // GNU General Public License for more details. 00015 00016 // Under Section 7 of GPL version 3, you are granted additional 00017 // permissions described in the GCC Runtime Library Exception, version 00018 // 3.1, as published by the Free Software Foundation. 00019 00020 // You should have received a copy of the GNU General Public License and 00021 // a copy of the GCC Runtime Library Exception along with this program; 00022 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 00023 // <http://www.gnu.org/licenses/>. 00024 00025 /** 00026 * @file bits/regex_automaton.tcc 00027 * This is an internal header file, included by other library headers. 00028 * Do not attempt to use it directly. @headername{regex} 00029 */ 00030 00031 namespace std _GLIBCXX_VISIBILITY(default) 00032 { 00033 namespace __detail 00034 { 00035 _GLIBCXX_BEGIN_NAMESPACE_VERSION 00036 00037 #ifdef _GLIBCXX_DEBUG 00038 inline std::ostream& 00039 _State_base::_M_print(std::ostream& ostr) const 00040 { 00041 switch (_M_opcode) 00042 { 00043 case _S_opcode_alternative: 00044 case _S_opcode_repeat: 00045 ostr << "alt next=" << _M_next << " alt=" << _M_alt; 00046 break; 00047 case _S_opcode_subexpr_begin: 00048 ostr << "subexpr begin next=" << _M_next << " index=" << _M_subexpr; 00049 break; 00050 case _S_opcode_subexpr_end: 00051 ostr << "subexpr end next=" << _M_next << " index=" << _M_subexpr; 00052 break; 00053 case _S_opcode_backref: 00054 ostr << "backref next=" << _M_next << " index=" << _M_backref_index; 00055 break; 00056 case _S_opcode_match: 00057 ostr << "match next=" << _M_next; 00058 break; 00059 case _S_opcode_accept: 00060 ostr << "accept next=" << _M_next; 00061 break; 00062 default: 00063 ostr << "unknown next=" << _M_next; 00064 break; 00065 } 00066 return ostr; 00067 } 00068 00069 // Prints graphviz dot commands for state. 00070 inline std::ostream& 00071 _State_base::_M_dot(std::ostream& __ostr, _StateIdT __id) const 00072 { 00073 switch (_M_opcode) 00074 { 00075 case _S_opcode_alternative: 00076 case _S_opcode_repeat: 00077 __ostr << __id << " [label=\"" << __id << "\\nALT\"];\n" 00078 << __id << " -> " << _M_next 00079 << " [label=\"next\", tailport=\"s\"];\n" 00080 << __id << " -> " << _M_alt 00081 << " [label=\"alt\", tailport=\"n\"];\n"; 00082 break; 00083 case _S_opcode_backref: 00084 __ostr << __id << " [label=\"" << __id << "\\nBACKREF " 00085 << _M_subexpr << "\"];\n" 00086 << __id << " -> " << _M_next << " [label=\"<match>\"];\n"; 00087 break; 00088 case _S_opcode_line_begin_assertion: 00089 __ostr << __id << " [label=\"" << __id << "\\nLINE_BEGIN \"];\n" 00090 << __id << " -> " << _M_next << " [label=\"epsilon\"];\n"; 00091 break; 00092 case _S_opcode_line_end_assertion: 00093 __ostr << __id << " [label=\"" << __id << "\\nLINE_END \"];\n" 00094 << __id << " -> " << _M_next << " [label=\"epsilon\"];\n"; 00095 break; 00096 case _S_opcode_word_boundary: 00097 __ostr << __id << " [label=\"" << __id << "\\nWORD_BOUNDRY " 00098 << _M_neg << "\"];\n" 00099 << __id << " -> " << _M_next << " [label=\"epsilon\"];\n"; 00100 break; 00101 case _S_opcode_subexpr_lookahead: 00102 __ostr << __id << " [label=\"" << __id << "\\nLOOK_AHEAD\"];\n" 00103 << __id << " -> " << _M_next 00104 << " [label=\"epsilon\", tailport=\"s\"];\n" 00105 << __id << " -> " << _M_alt 00106 << " [label=\"<assert>\", tailport=\"n\"];\n"; 00107 break; 00108 case _S_opcode_subexpr_begin: 00109 __ostr << __id << " [label=\"" << __id << "\\nSBEGIN " 00110 << _M_subexpr << "\"];\n" 00111 << __id << " -> " << _M_next << " [label=\"epsilon\"];\n"; 00112 break; 00113 case _S_opcode_subexpr_end: 00114 __ostr << __id << " [label=\"" << __id << "\\nSEND " 00115 << _M_subexpr << "\"];\n" 00116 << __id << " -> " << _M_next << " [label=\"epsilon\"];\n"; 00117 break; 00118 case _S_opcode_dummy: 00119 break; 00120 case _S_opcode_match: 00121 __ostr << __id << " [label=\"" << __id << "\\nMATCH\"];\n" 00122 << __id << " -> " << _M_next << " [label=\"<match>\"];\n"; 00123 break; 00124 case _S_opcode_accept: 00125 __ostr << __id << " [label=\"" << __id << "\\nACC\"];\n" ; 00126 break; 00127 default: 00128 _GLIBCXX_DEBUG_ASSERT(false); 00129 break; 00130 } 00131 return __ostr; 00132 } 00133 00134 template<typename _TraitsT> 00135 std::ostream& 00136 _NFA<_TraitsT>::_M_dot(std::ostream& __ostr) const 00137 { 00138 __ostr << "digraph _Nfa {\n" 00139 " rankdir=LR;\n"; 00140 for (size_t __i = 0; __i < this->size(); ++__i) 00141 (*this)[__i]._M_dot(__ostr, __i); 00142 __ostr << "}\n"; 00143 return __ostr; 00144 } 00145 #endif 00146 00147 template<typename _TraitsT> 00148 _StateIdT 00149 _NFA<_TraitsT>::_M_insert_backref(size_t __index) 00150 { 00151 if (this->_M_flags & regex_constants::__polynomial) 00152 __throw_regex_error(regex_constants::error_complexity, 00153 "Unexpected back-reference in polynomial mode."); 00154 // To figure out whether a backref is valid, a stack is used to store 00155 // unfinished sub-expressions. For example, when parsing 00156 // "(a(b)(c\\1(d)))" at '\\1', _M_subexpr_count is 3, indicating that 3 00157 // sub expressions are parsed or partially parsed(in the stack), aka, 00158 // "(a..", "(b)" and "(c.."). 00159 // _M_paren_stack is {1, 3}, for incomplete "(a.." and "(c..". At this 00160 // time, "\\2" is valid, but "\\1" and "\\3" are not. 00161 if (__index >= _M_subexpr_count) 00162 __throw_regex_error( 00163 regex_constants::error_backref, 00164 "Back-reference index exceeds current sub-expression count."); 00165 for (auto __it : this->_M_paren_stack) 00166 if (__index == __it) 00167 __throw_regex_error( 00168 regex_constants::error_backref, 00169 "Back-reference referred to an opened sub-expression."); 00170 this->_M_has_backref = true; 00171 _StateT __tmp(_S_opcode_backref); 00172 __tmp._M_backref_index = __index; 00173 return _M_insert_state(std::move(__tmp)); 00174 } 00175 00176 template<typename _TraitsT> 00177 void 00178 _NFA<_TraitsT>::_M_eliminate_dummy() 00179 { 00180 for (auto& __it : *this) 00181 { 00182 while (__it._M_next >= 0 && (*this)[__it._M_next]._M_opcode() 00183 == _S_opcode_dummy) 00184 __it._M_next = (*this)[__it._M_next]._M_next; 00185 if (__it._M_has_alt()) 00186 while (__it._M_alt >= 0 && (*this)[__it._M_alt]._M_opcode() 00187 == _S_opcode_dummy) 00188 __it._M_alt = (*this)[__it._M_alt]._M_next; 00189 } 00190 } 00191 00192 // Just apply DFS on the sequence and re-link their links. 00193 template<typename _TraitsT> 00194 _StateSeq<_TraitsT> 00195 _StateSeq<_TraitsT>::_M_clone() 00196 { 00197 std::map<_StateIdT, _StateIdT> __m; 00198 std::stack<_StateIdT> __stack; 00199 __stack.push(_M_start); 00200 while (!__stack.empty()) 00201 { 00202 auto __u = __stack.top(); 00203 __stack.pop(); 00204 auto __dup = _M_nfa[__u]; 00205 // _M_insert_state() never return -1 00206 auto __id = _M_nfa._M_insert_state(std::move(__dup)); 00207 __m[__u] = __id; 00208 if (__dup._M_has_alt()) 00209 if (__dup._M_alt != _S_invalid_state_id 00210 && __m.count(__dup._M_alt) == 0) 00211 __stack.push(__dup._M_alt); 00212 if (__u == _M_end) 00213 continue; 00214 if (__dup._M_next != _S_invalid_state_id 00215 && __m.count(__dup._M_next) == 0) 00216 __stack.push(__dup._M_next); 00217 } 00218 for (auto __it : __m) 00219 { 00220 auto __v = __it.second; 00221 auto& __ref = _M_nfa[__v]; 00222 if (__ref._M_next != _S_invalid_state_id) 00223 { 00224 __glibcxx_assert(__m.count(__ref._M_next) > 0); 00225 __ref._M_next = __m[__ref._M_next]; 00226 } 00227 if (__ref._M_has_alt()) 00228 if (__ref._M_alt != _S_invalid_state_id) 00229 { 00230 __glibcxx_assert(__m.count(__ref._M_alt) > 0); 00231 __ref._M_alt = __m[__ref._M_alt]; 00232 } 00233 } 00234 return _StateSeq(_M_nfa, __m[_M_start], __m[_M_end]); 00235 } 00236 00237 _GLIBCXX_END_NAMESPACE_VERSION 00238 } // namespace __detail 00239 } // namespace