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// class template regex -*- C++ -*-

// Copyright (C) 2013-2015 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_automaton.tcc

 *  This is an internal header file, included by other library headers.

 *  Do not attempt to use it directly. @headername{regex}

 */

namespace std _GLIBCXX_VISIBILITY(default)

{

namespace __detail

{

_GLIBCXX_BEGIN_NAMESPACE_VERSION

#ifdef _GLIBCXX_DEBUG

  inline std::ostream&

  _State_base::_M_print(std::ostream& ostr) const

  {

    switch (_M_opcode)

    {

      case _S_opcode_alternative:

      case _S_opcode_repeat:

	ostr << "alt next=" << _M_next << " alt=" << _M_alt;

	break;

      case _S_opcode_subexpr_begin:

	ostr << "subexpr begin next=" << _M_next << " index=" << _M_subexpr;

	break;

      case _S_opcode_subexpr_end:

	ostr << "subexpr end next=" << _M_next << " index=" << _M_subexpr;

	break;

      case _S_opcode_backref:

	ostr << "backref next=" << _M_next << " index=" << _M_backref_index;

	break;

      case _S_opcode_match:

	ostr << "match next=" << _M_next;

	break;

      case _S_opcode_accept:

	ostr << "accept next=" << _M_next;

	break;

      default:

	ostr << "unknown next=" << _M_next;

	break;

    }

    return ostr;

  }

  // Prints graphviz dot commands for state.

  inline std::ostream&

  _State_base::_M_dot(std::ostream& __ostr, _StateIdT __id) const

  {

    switch (_M_opcode)

    {

      case _S_opcode_alternative:

      case _S_opcode_repeat:

	__ostr << __id << " [label=\"" << __id << "\\nALT\"];\n"

	       << __id << " -> " << _M_next

	       << " [label=\"next\", tailport=\"s\"];\n"

	       << __id << " -> " << _M_alt

	       << " [label=\"alt\", tailport=\"n\"];\n";

	break;

      case _S_opcode_backref:

	__ostr << __id << " [label=\"" << __id << "\\nBACKREF "

	       << _M_subexpr << "\"];\n"

	       << __id << " -> " << _M_next << " [label=\"\"];\n";

	break;

      case _S_opcode_line_begin_assertion:

	__ostr << __id << " [label=\"" << __id << "\\nLINE_BEGIN \"];\n"

	       << __id << " -> " << _M_next << " [label=\"epsilon\"];\n";

	break;

      case _S_opcode_line_end_assertion:

	__ostr << __id << " [label=\"" << __id << "\\nLINE_END \"];\n"

	       << __id << " -> " << _M_next << " [label=\"epsilon\"];\n";

	break;

      case _S_opcode_word_boundary:

	__ostr << __id << " [label=\"" << __id << "\\nWORD_BOUNDRY "

	       << _M_neg << "\"];\n"

	       << __id << " -> " << _M_next << " [label=\"epsilon\"];\n";

	break;

      case _S_opcode_subexpr_lookahead:

	__ostr << __id << " [label=\"" << __id << "\\nLOOK_AHEAD\"];\n"

	       << __id << " -> " << _M_next

	       << " [label=\"epsilon\", tailport=\"s\"];\n"

	       << __id << " -> " << _M_alt

	       << " [label=\"\", tailport=\"n\"];\n";

	break;

      case _S_opcode_subexpr_begin:

	__ostr << __id << " [label=\"" << __id << "\\nSBEGIN "

	       << _M_subexpr << "\"];\n"

	       << __id << " -> " << _M_next << " [label=\"epsilon\"];\n";

	break;

      case _S_opcode_subexpr_end:

	__ostr << __id << " [label=\"" << __id << "\\nSEND "

	       << _M_subexpr << "\"];\n"

	       << __id << " -> " << _M_next << " [label=\"epsilon\"];\n";

	break;

      case _S_opcode_dummy:

	break;

      case _S_opcode_match:

	__ostr << __id << " [label=\"" << __id << "\\nMATCH\"];\n"

	       << __id << " -> " << _M_next << " [label=\"\"];\n";

	break;

      case _S_opcode_accept:

	__ostr << __id << " [label=\"" << __id << "\\nACC\"];\n" ;

	break;

      default:

	_GLIBCXX_DEBUG_ASSERT(false);

	break;

    }

    return __ostr;

  }

  template

    std::ostream&

    _NFA<_TraitsT>::_M_dot(std::ostream& __ostr) const

    {

      __ostr << "digraph _Nfa {\n"

		"  rankdir=LR;\n";

      for (size_t __i = 0; __i < this->size(); ++__i)

	(*this)[__i]._M_dot(__ostr, __i);

      __ostr << "}\n";

      return __ostr;

    }

#endif

  template

    _StateIdT

    _NFA<_TraitsT>::_M_insert_backref(size_t __index)

    {

      // To figure out whether a backref is valid, a stack is used to store

      // unfinished sub-expressions. For example, when parsing

      // "(a(b)(c\\1(d)))" at '\\1', _M_subexpr_count is 3, indicating that 3

      // sub expressions are parsed or partially parsed(in the stack), aka,

      // "(a..", "(b)" and "(c..").

      // _M_paren_stack is {1, 3}, for incomplete "(a.." and "(c..". At this

      // time, "\\2" is valid, but "\\1" and "\\3" are not.

      if (__index >= _M_subexpr_count)

	__throw_regex_error(regex_constants::error_backref);

      for (auto __it : this->_M_paren_stack)

	if (__index == __it)

	  __throw_regex_error(regex_constants::error_backref);

      this->_M_has_backref = true;

      _StateT __tmp(_S_opcode_backref);

      __tmp._M_backref_index = __index;

      return _M_insert_state(std::move(__tmp));

    }

  template

    void

    _NFA<_TraitsT>::_M_eliminate_dummy()

    {

      for (auto& __it : *this)

	{

	  while (__it._M_next >= 0 && (*this)[__it._M_next]._M_opcode

		 == _S_opcode_dummy)

	    __it._M_next = (*this)[__it._M_next]._M_next;

	  if (__it._M_opcode == _S_opcode_alternative

	      || __it._M_opcode == _S_opcode_repeat

	      || __it._M_opcode == _S_opcode_subexpr_lookahead)

	    while (__it._M_alt >= 0 && (*this)[__it._M_alt]._M_opcode

		   == _S_opcode_dummy)

	      __it._M_alt = (*this)[__it._M_alt]._M_next;

	}

    }

  // Just apply DFS on the sequence and re-link their links.

  template

    _StateSeq<_TraitsT>

    _StateSeq<_TraitsT>::_M_clone()

    {

      std::map<_StateIdT, _StateIdT> __m;

      std::stack<_StateIdT> __stack;

      __stack.push(_M_start);

      while (!__stack.empty())

	{

	  auto __u = __stack.top();

	  __stack.pop();

	  auto __dup = _M_nfa[__u];

	  // _M_insert_state() never return -1

	  auto __id = _M_nfa._M_insert_state(__dup);

	  __m[__u] = __id;

	  if (__dup._M_opcode == _S_opcode_alternative

	      || __dup._M_opcode == _S_opcode_repeat

	      || __dup._M_opcode == _S_opcode_subexpr_lookahead)

	    if (__dup._M_alt != _S_invalid_state_id

		&& __m.count(__dup._M_alt) == 0)

	      __stack.push(__dup._M_alt);

	  if (__u == _M_end)

	    continue;

	  if (__dup._M_next != _S_invalid_state_id

	      && __m.count(__dup._M_next) == 0)

	    __stack.push(__dup._M_next);

	}

      for (auto __it : __m)

	{

	  auto __v = __it.second;

	  auto& __ref = _M_nfa[__v];

	  if (__ref._M_next != _S_invalid_state_id)

	    {

	      _GLIBCXX_DEBUG_ASSERT(__m.count(__ref._M_next) > 0);

	      __ref._M_next = __m[__ref._M_next];

	    }

	  if (__ref._M_opcode == _S_opcode_alternative

	      || __ref._M_opcode == _S_opcode_repeat

	      || __ref._M_opcode == _S_opcode_subexpr_lookahead)

	    if (__ref._M_alt != _S_invalid_state_id)

	      {

		_GLIBCXX_DEBUG_ASSERT(__m.count(__ref._M_alt) > 0);

		__ref._M_alt = __m[__ref._M_alt];

	      }

	}

      return _StateSeq(_M_nfa, __m[_M_start], __m[_M_end]);

    }

_GLIBCXX_END_NAMESPACE_VERSION

} // namespace __detail

} // namespace