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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_scanner.h

 *  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

  /**

   * @addtogroup regex-detail

   * @{

   */

  struct _ScannerBase

  {

  public:

    /// Token types returned from the scanner.

    enum _TokenT

    {

      _S_token_anychar,

      _S_token_ord_char,

      _S_token_oct_num,

      _S_token_hex_num,

      _S_token_backref,

      _S_token_subexpr_begin,

      _S_token_subexpr_no_group_begin,

      _S_token_subexpr_lookahead_begin, // neg if _M_value[0] == 'n'

      _S_token_subexpr_end,

      _S_token_bracket_begin,

      _S_token_bracket_neg_begin,

      _S_token_bracket_end,

      _S_token_interval_begin,

      _S_token_interval_end,

      _S_token_quoted_class,

      _S_token_char_class_name,

      _S_token_collsymbol,

      _S_token_equiv_class_name,

      _S_token_opt,

      _S_token_or,

      _S_token_closure0,

      _S_token_closure1,

      _S_token_line_begin,

      _S_token_line_end,

      _S_token_word_bound, // neg if _M_value[0] == 'n'

      _S_token_comma,

      _S_token_dup_count,

      _S_token_eof,

      _S_token_unknown

    };

  protected:

    typedef regex_constants::syntax_option_type _FlagT;

    enum _StateT

    {

      _S_state_normal,

      _S_state_in_brace,

      _S_state_in_bracket,

    };

  protected:

    _ScannerBase(_FlagT __flags)

    : _M_state(_S_state_normal),

    _M_flags(__flags),

    _M_escape_tbl(_M_is_ecma()

		  ? _M_ecma_escape_tbl

		  : _M_awk_escape_tbl),

    _M_spec_char(_M_is_ecma()

		 ? _M_ecma_spec_char

		 : _M_flags & regex_constants::basic

		 ? _M_basic_spec_char

		 : _M_flags & regex_constants::extended

		 ? _M_extended_spec_char

		 : _M_flags & regex_constants::grep

		 ?  ".[\\*^$\n"

		 : _M_flags & regex_constants::egrep

		 ? ".[\\()*+?{|^$\n"

		 : _M_flags & regex_constants::awk

		 ? _M_extended_spec_char

		 : nullptr),

    _M_at_bracket_start(false)

    { __glibcxx_assert(_M_spec_char); }

  protected:

    const char*

    _M_find_escape(char __c)

    {

      auto __it = _M_escape_tbl;

      for (; __it->first != '\0'; ++__it)

	if (__it->first == __c)

	  return &__it->second;

      return nullptr;

    }

    bool

    _M_is_ecma() const

    { return _M_flags & regex_constants::ECMAScript; }

    bool

    _M_is_basic() const

    { return _M_flags & (regex_constants::basic | regex_constants::grep); }

    bool

    _M_is_extended() const

    {

      return _M_flags & (regex_constants::extended

			 | regex_constants::egrep

			 | regex_constants::awk);

    }

    bool

    _M_is_grep() const

    { return _M_flags & (regex_constants::grep | regex_constants::egrep); }

    bool

    _M_is_awk() const

    { return _M_flags & regex_constants::awk; }

  protected:

    // TODO: Make them static in the next abi change.

    const std::pair _M_token_tbl[9] =

      {

	{'^', _S_token_line_begin},

	{'$', _S_token_line_end},

	{'.', _S_token_anychar},

	{'*', _S_token_closure0},

	{'+', _S_token_closure1},

	{'?', _S_token_opt},

	{'|', _S_token_or},

	{'\n', _S_token_or}, // grep and egrep

	{'\0', _S_token_or},

      };

    const std::pair _M_ecma_escape_tbl[8] =

      {

	{'0', '\0'},

	{'b', '\b'},

	{'f', '\f'},

	{'n', '\n'},

	{'r', '\r'},

	{'t', '\t'},

	{'v', '\v'},

	{'\0', '\0'},

      };

    const std::pair _M_awk_escape_tbl[11] =

      {

	{'"', '"'},

	{'/', '/'},

	{'\\', '\\'},

	{'a', '\a'},

	{'b', '\b'},

	{'f', '\f'},

	{'n', '\n'},

	{'r', '\r'},

	{'t', '\t'},

	{'v', '\v'},

	{'\0', '\0'},

      };

    const char* _M_ecma_spec_char = "^$\\.*+?()[]{}|";

    const char* _M_basic_spec_char = ".[\\*^$";

    const char* _M_extended_spec_char = ".[\\()*+?{|^$";

    _StateT                       _M_state;

    _FlagT                        _M_flags;

    _TokenT                       _M_token;

    const std::pair*  _M_escape_tbl;

    const char*                   _M_spec_char;

    bool                          _M_at_bracket_start;

  };

  /**

   * @brief Scans an input range for regex tokens.

   *

   * The %_Scanner class interprets the regular expression pattern in

   * the input range passed to its constructor as a sequence of parse

   * tokens passed to the regular expression compiler.  The sequence

   * of tokens provided depends on the flag settings passed to the

   * constructor: different regular expression grammars will interpret

   * the same input pattern in syntactically different ways.

   */

  template

    class _Scanner

    : public _ScannerBase

    {

    public:

      typedef const _CharT*                                       _IterT;

      typedef std::basic_string<_CharT>                           _StringT;

      typedef regex_constants::syntax_option_type                 _FlagT;

      typedef const std::ctype<_CharT>                            _CtypeT;

      _Scanner(_IterT __begin, _IterT __end,

	       _FlagT __flags, std::locale __loc);

      void

      _M_advance();

      _TokenT

      _M_get_token() const

      { return _M_token; }

      const _StringT&

      _M_get_value() const

      { return _M_value; }

#ifdef _GLIBCXX_DEBUG

      std::ostream&

      _M_print(std::ostream&);

#endif

    private:

      void

      _M_scan_normal();

      void

      _M_scan_in_bracket();

      void

      _M_scan_in_brace();

      void

      _M_eat_escape_ecma();

      void

      _M_eat_escape_posix();

      void

      _M_eat_escape_awk();

      void

      _M_eat_class(char);

      _IterT                        _M_current;

      _IterT                        _M_end;

      _CtypeT&                      _M_ctype;

      _StringT                      _M_value;

      void (_Scanner::* _M_eat_escape)();

    };

 //@} regex-detail

_GLIBCXX_END_NAMESPACE_VERSION

} // namespace __detail

} // namespace std

#include