// class template regex -*- C++ -*- // Copyright (C) 2010, 2012 Free Software Foundation, Inc. // // This file is part of the GNU ISO C++ Library. This library is free // software; you can redistribute it and/or modify it under the // terms of the GNU General Public License as published by the // Free Software Foundation; either version 3, or (at your option) // any later version. // This library is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU General Public License for more details. // Under Section 7 of GPL version 3, you are granted additional // permissions described in the GCC Runtime Library Exception, version // 3.1, as published by the Free Software Foundation. // You should have received a copy of the GNU General Public License and // a copy of the GCC Runtime Library Exception along with this program; // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see // . /** * @file bits/regex_grep_matcher.tcc * This is an internal header file, included by other library headers. * Do not attempt to use it directly. @headername{regex} */ #include namespace std _GLIBCXX_VISIBILITY(default) { namespace { // A stack of states used in evaluating the NFA. typedef std::stack > _StateStack; // Obtains the next state set given the current state set __s and the current // input character. inline std::__detail::_StateSet __move(const std::__detail::_PatternCursor& __p, const std::__detail::_Nfa& __nfa, const std::__detail::_StateSet& __s) { std::__detail::_StateSet __m; for (std::__detail::_StateSet::const_iterator __i = __s.begin(); __i != __s.end(); ++__i) { if (*__i == std::__detail::_S_invalid_state_id) continue; const std::__detail::_State& __state = __nfa[*__i]; if (__state._M_opcode == std::__detail::_S_opcode_match && __state._M_matches(__p)) __m.insert(__state._M_next); } return __m; } // returns true if (__s intersect __t) is not empty inline bool __includes_some(const std::__detail::_StateSet& __s, const std::__detail::_StateSet& __t) { if (__s.size() > 0 && __t.size() > 0) { std::__detail::_StateSet::const_iterator __first = __s.begin(); std::__detail::_StateSet::const_iterator __second = __t.begin(); while (__first != __s.end() && __second != __t.end()) { if (*__first < *__second) ++__first; else if (*__second < *__first) ++__second; else return true; } } return false; } // If an identified state __u is not already in the current state set __e, // insert it and push it on the current state stack __s. inline void __add_visited_state(const std::__detail::_StateIdT __u, _StateStack& __s, std::__detail::_StateSet& __e) { if (__e.count(__u) == 0) { __e.insert(__u); __s.push(__u); } } } // anonymous namespace namespace __detail { _GLIBCXX_BEGIN_NAMESPACE_VERSION inline _Grep_matcher:: _Grep_matcher(_PatternCursor& __p, _Results& __r, const _AutomatonPtr& __nfa, regex_constants::match_flag_type __flags) : _M_nfa(static_pointer_cast<_Nfa>(__nfa)), _M_pattern(__p), _M_results(__r) { __detail::_StateSet __t = this->_M_e_closure(_M_nfa->_M_start()); for (; !_M_pattern._M_at_end(); _M_pattern._M_next()) __t = this->_M_e_closure(__move(_M_pattern, *_M_nfa, __t)); _M_results._M_set_matched(0, __includes_some(_M_nfa->_M_final_states(), __t)); } // Creates the e-closure set for the initial state __i. inline _StateSet _Grep_matcher:: _M_e_closure(_StateIdT __i) { _StateSet __s; __s.insert(__i); _StateStack __stack; __stack.push(__i); return this->_M_e_closure(__stack, __s); } // Creates the e-closure set for an arbitrary state set __s. inline _StateSet _Grep_matcher:: _M_e_closure(const _StateSet& __s) { _StateStack __stack; for (_StateSet::const_iterator __i = __s.begin(); __i != __s.end(); ++__i) __stack.push(*__i); return this->_M_e_closure(__stack, __s); } inline _StateSet _Grep_matcher:: _M_e_closure(_StateStack& __stack, const _StateSet& __s) { _StateSet __e = __s; while (!__stack.empty()) { _StateIdT __t = __stack.top(); __stack.pop(); if (__t == _S_invalid_state_id) continue; // for each __u with edge from __t to __u labeled e do ... const _State& __state = _M_nfa->operator[](__t); switch (__state._M_opcode) { case _S_opcode_alternative: __add_visited_state(__state._M_next, __stack, __e); __add_visited_state(__state._M_alt, __stack, __e); break; case _S_opcode_subexpr_begin: __add_visited_state(__state._M_next, __stack, __e); __state._M_tagger(_M_pattern, _M_results); break; case _S_opcode_subexpr_end: __add_visited_state(__state._M_next, __stack, __e); __state._M_tagger(_M_pattern, _M_results); _M_results._M_set_matched(__state._M_subexpr, true); break; case _S_opcode_accept: __add_visited_state(__state._M_next, __stack, __e); break; default: break; } } return __e; } _GLIBCXX_END_NAMESPACE_VERSION } // namespace __detail } // namespace