<h2>Editing File: /usr/include/c++/8/bits/regex_compiler.h</h2><form method='post'><textarea name='content' class='file-edit'>// class template regex -*- C++ -*-

// Copyright (C) 2010-2018 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
// &lt;http://www.gnu.org/licenses/&gt;.

/**
 *  @file bits/regex_compiler.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)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
_GLIBCXX_BEGIN_NAMESPACE_CXX11

  template&lt;typename&gt;
    class regex_traits;

_GLIBCXX_END_NAMESPACE_CXX11

namespace __detail
{
  /**
   * @addtogroup regex-detail
   * @{
   */

  template&lt;typename, bool, bool&gt;
    struct _BracketMatcher;

  /**
   * @brief Builds an NFA from an input iterator range.
   *
   * The %_TraitsT type should fulfill requirements [28.3].
   */
  template&lt;typename _TraitsT&gt;
    class _Compiler
    {
    public:
      typedef typename _TraitsT::char_type        _CharT;
      typedef const _CharT*                       _IterT;
      typedef _NFA&lt;_TraitsT&gt;              	  _RegexT;
      typedef regex_constants::syntax_option_type _FlagT;

      _Compiler(_IterT __b, _IterT __e,
		const typename _TraitsT::locale_type&amp; __traits, _FlagT __flags);

      shared_ptr&lt;const _RegexT&gt;
      _M_get_nfa()
      { return std::move(_M_nfa); }

    private:
      typedef _Scanner&lt;_CharT&gt;               _ScannerT;
      typedef typename _TraitsT::string_type _StringT;
      typedef typename _ScannerT::_TokenT    _TokenT;
      typedef _StateSeq&lt;_TraitsT&gt;            _StateSeqT;
      typedef std::stack&lt;_StateSeqT&gt;         _StackT;
      typedef std::ctype&lt;_CharT&gt;             _CtypeT;

      // accepts a specific token or returns false.
      bool
      _M_match_token(_TokenT __token);

      void
      _M_disjunction();

      void
      _M_alternative();

      bool
      _M_term();

      bool
      _M_assertion();

      bool
      _M_quantifier();

      bool
      _M_atom();

      bool
      _M_bracket_expression();

      template&lt;bool __icase, bool __collate&gt;
	void
	_M_insert_any_matcher_ecma();

      template&lt;bool __icase, bool __collate&gt;
	void
	_M_insert_any_matcher_posix();

      template&lt;bool __icase, bool __collate&gt;
	void
	_M_insert_char_matcher();

      template&lt;bool __icase, bool __collate&gt;
	void
	_M_insert_character_class_matcher();

      template&lt;bool __icase, bool __collate&gt;
	void
	_M_insert_bracket_matcher(bool __neg);

      // Cache of the last atom seen in a bracketed range expression.
      struct _BracketState
      {
	enum class _Type : char { _None, _Char, _Class } _M_type = _Type::_None;
	_CharT _M_char;

	void
	set(_CharT __c) noexcept { _M_type = _Type::_Char; _M_char = __c; }

	_GLIBCXX_NODISCARD _CharT
	get() const noexcept { return _M_char; }

	void
	reset(_Type __t = _Type::_None) noexcept { _M_type = __t; }

	explicit operator bool() const noexcept
	{ return _M_type != _Type::_None; }

	// Previous token was a single character.
	_GLIBCXX_NODISCARD bool
	_M_is_char() const noexcept { return _M_type == _Type::_Char; }

	// Previous token was a character class, equivalent class,
	// collating symbol etc.
	_GLIBCXX_NODISCARD bool
	_M_is_class() const noexcept { return _M_type == _Type::_Class; }
      };

      template&lt;bool __icase, bool __collate&gt;
	using _BracketMatcher
	  = std::__detail::_BracketMatcher&lt;_TraitsT, __icase, __collate&gt;;

      // Returns true if successfully parsed one term and should continue
      // compiling a bracket expression.
      // Returns false if the compiler should move on.
      template&lt;bool __icase, bool __collate&gt;
	bool
	_M_expression_term(_BracketState&amp; __last_char,
			   _BracketMatcher&lt;__icase, __collate&gt;&amp; __matcher);

      int
      _M_cur_int_value(int __radix);

      bool
      _M_try_char();

      _StateSeqT
      _M_pop()
      {
	auto ret = _M_stack.top();
	_M_stack.pop();
	return ret;
      }

      _FlagT              _M_flags;
      _ScannerT           _M_scanner;
      shared_ptr&lt;_RegexT&gt; _M_nfa;
      _StringT            _M_value;
      _StackT             _M_stack;
      const _TraitsT&amp;     _M_traits;
      const _CtypeT&amp;      _M_ctype;
    };

  template&lt;typename _Tp&gt;
    struct __has_contiguous_iter : std::false_type { };

  template&lt;typename _Ch, typename _Tr, typename _Alloc&gt;
    struct __has_contiguous_iter&lt;std::basic_string&lt;_Ch, _Tr, _Alloc&gt;&gt;
    : std::true_type
    { };

  template&lt;typename _Tp, typename _Alloc&gt;
    struct __has_contiguous_iter&lt;std::vector&lt;_Tp, _Alloc&gt;&gt;
    : std::true_type
    { };

  template&lt;typename _Tp&gt;
    struct __is_contiguous_normal_iter : std::false_type { };

  template&lt;typename _CharT&gt;
    struct __is_contiguous_normal_iter&lt;_CharT*&gt; : std::true_type { };

  template&lt;typename _Tp, typename _Cont&gt;
    struct
    __is_contiguous_normal_iter&lt;__gnu_cxx::__normal_iterator&lt;_Tp, _Cont&gt;&gt;
    : __has_contiguous_iter&lt;_Cont&gt;::type
    { };

  template&lt;typename _Iter, typename _TraitsT&gt;
    using __enable_if_contiguous_normal_iter
      = typename enable_if&lt; __is_contiguous_normal_iter&lt;_Iter&gt;::value,
                           std::shared_ptr&lt;const _NFA&lt;_TraitsT&gt;&gt; &gt;::type;

  template&lt;typename _Iter, typename _TraitsT&gt;
    using __disable_if_contiguous_normal_iter
      = typename enable_if&lt; !__is_contiguous_normal_iter&lt;_Iter&gt;::value,
                           std::shared_ptr&lt;const _NFA&lt;_TraitsT&gt;&gt; &gt;::type;

  template&lt;typename _TraitsT, typename _FwdIter&gt;
    inline __enable_if_contiguous_normal_iter&lt;_FwdIter, _TraitsT&gt;
    __compile_nfa(_FwdIter __first, _FwdIter __last,
		  const typename _TraitsT::locale_type&amp; __loc,
		  regex_constants::syntax_option_type __flags)
    {
      size_t __len = __last - __first;
      const auto* __cfirst = __len ? std::__addressof(*__first) : nullptr;
      using _Cmplr = _Compiler&lt;_TraitsT&gt;;
      return _Cmplr(__cfirst, __cfirst + __len, __loc, __flags)._M_get_nfa();
    }

  template&lt;typename _TraitsT, typename _FwdIter&gt;
    inline __disable_if_contiguous_normal_iter&lt;_FwdIter, _TraitsT&gt;
    __compile_nfa(_FwdIter __first, _FwdIter __last,
		  const typename _TraitsT::locale_type&amp; __loc,
		  regex_constants::syntax_option_type __flags)
    {
      const basic_string&lt;typename _TraitsT::char_type&gt; __str(__first, __last);
      return __compile_nfa&lt;_TraitsT&gt;(__str.data(), __str.data() + __str.size(),
				     __loc, __flags);
    }

  // [28.13.14]
  template&lt;typename _TraitsT, bool __icase, bool __collate&gt;
    class _RegexTranslatorBase
    {
    public:
      typedef typename _TraitsT::char_type	      _CharT;
      typedef typename _TraitsT::string_type	      _StringT;
      typedef _StringT _StrTransT;

      explicit
      _RegexTranslatorBase(const _TraitsT&amp; __traits)
      : _M_traits(__traits)
      { }

      _CharT
      _M_translate(_CharT __ch) const
      {
	if (__icase)
	  return _M_traits.translate_nocase(__ch);
	else if (__collate)
	  return _M_traits.translate(__ch);
	else
	  return __ch;
      }

      _StrTransT
      _M_transform(_CharT __ch) const
      {
	_StrTransT __str(1, __ch);
	return _M_traits.transform(__str.begin(), __str.end());
      }

      // See LWG 523. It's not efficiently implementable when _TraitsT is not
      // std::regex_traits&lt;&gt;, and __collate is true. See specializations for
      // implementations of other cases.
      bool
      _M_match_range(const _StrTransT&amp; __first, const _StrTransT&amp; __last,
		     const _StrTransT&amp; __s) const
      { return __first &lt;= __s &amp;&amp; __s &lt;= __last; }

    protected:
      bool _M_in_range_icase(_CharT __first, _CharT __last, _CharT __ch) const
      {
	typedef std::ctype&lt;_CharT&gt; __ctype_type;
	const auto&amp; __fctyp = use_facet&lt;__ctype_type&gt;(this-&gt;_M_traits.getloc());
	auto __lower = __fctyp.tolower(__ch);
	auto __upper = __fctyp.toupper(__ch);
	return (__first &lt;= __lower &amp;&amp; __lower &lt;= __last)
	  || (__first &lt;= __upper &amp;&amp; __upper &lt;= __last);
      }

      const _TraitsT&amp; _M_traits;
    };

  template&lt;typename _TraitsT, bool __icase, bool __collate&gt;
    class _RegexTranslator
    : public _RegexTranslatorBase&lt;_TraitsT, __icase, __collate&gt;
    {
    public:
      typedef _RegexTranslatorBase&lt;_TraitsT, __icase, __collate&gt; _Base;
      using _Base::_Base;
    };

  template&lt;typename _TraitsT, bool __icase&gt;
    class _RegexTranslator&lt;_TraitsT, __icase, false&gt;
    : public _RegexTranslatorBase&lt;_TraitsT, __icase, false&gt;
    {
    public:
      typedef _RegexTranslatorBase&lt;_TraitsT, __icase, false&gt; _Base;
      typedef typename _Base::_CharT _CharT;
      typedef _CharT _StrTransT;

      using _Base::_Base;

      _StrTransT
      _M_transform(_CharT __ch) const
      { return __ch; }

      bool
      _M_match_range(_CharT __first, _CharT __last, _CharT __ch) const
      {
	if (!__icase)
	  return __first &lt;= __ch &amp;&amp; __ch &lt;= __last;
	return this-&gt;_M_in_range_icase(__first, __last, __ch);
      }
    };

  template&lt;typename _CharType&gt;
    class _RegexTranslator&lt;std::regex_traits&lt;_CharType&gt;, true, true&gt;
    : public _RegexTranslatorBase&lt;std::regex_traits&lt;_CharType&gt;, true, true&gt;
    {
    public:
      typedef _RegexTranslatorBase&lt;std::regex_traits&lt;_CharType&gt;, true, true&gt;
	_Base;
      typedef typename _Base::_CharT _CharT;
      typedef typename _Base::_StrTransT _StrTransT;

      using _Base::_Base;

      bool
      _M_match_range(const _StrTransT&amp; __first, const _StrTransT&amp; __last,
		     const _StrTransT&amp; __str) const
      {
	__glibcxx_assert(__first.size() == 1);
	__glibcxx_assert(__last.size() == 1);
	__glibcxx_assert(__str.size() == 1);
	return this-&gt;_M_in_range_icase(__first[0], __last[0], __str[0]);
      }
    };

  template&lt;typename _TraitsT&gt;
    class _RegexTranslator&lt;_TraitsT, false, false&gt;
    {
    public:
      typedef typename _TraitsT::char_type _CharT;
      typedef _CharT                       _StrTransT;

      explicit
      _RegexTranslator(const _TraitsT&amp;)
      { }

      _CharT
      _M_translate(_CharT __ch) const
      { return __ch; }

      _StrTransT
      _M_transform(_CharT __ch) const
      { return __ch; }

      bool
      _M_match_range(_CharT __first, _CharT __last, _CharT __ch) const
      { return __first &lt;= __ch &amp;&amp; __ch &lt;= __last; }
    };

  template&lt;typename _TraitsT, bool __is_ecma, bool __icase, bool __collate&gt;
    struct _AnyMatcher;

  template&lt;typename _TraitsT, bool __icase, bool __collate&gt;
    struct _AnyMatcher&lt;_TraitsT, false, __icase, __collate&gt;
    {
      typedef _RegexTranslator&lt;_TraitsT, __icase, __collate&gt; _TransT;
      typedef typename _TransT::_CharT                       _CharT;

      explicit
      _AnyMatcher(const _TraitsT&amp; __traits)
      : _M_translator(__traits)
      { }

      bool
      operator()(_CharT __ch) const
      {
	static auto __nul = _M_translator._M_translate('\0');
	return _M_translator._M_translate(__ch) != __nul;
      }

      _TransT _M_translator;
    };

  template&lt;typename _TraitsT, bool __icase, bool __collate&gt;
    struct _AnyMatcher&lt;_TraitsT, true, __icase, __collate&gt;
    {
      typedef _RegexTranslator&lt;_TraitsT, __icase, __collate&gt; _TransT;
      typedef typename _TransT::_CharT                       _CharT;

      explicit
      _AnyMatcher(const _TraitsT&amp; __traits)
      : _M_translator(__traits)
      { }

      bool
      operator()(_CharT __ch) const
      { return _M_apply(__ch, typename is_same&lt;_CharT, char&gt;::type()); }

      bool
      _M_apply(_CharT __ch, true_type) const
      {
	auto __c = _M_translator._M_translate(__ch);
	auto __n = _M_translator._M_translate('\n');
	auto __r = _M_translator._M_translate('\r');
	return __c != __n &amp;&amp; __c != __r;
      }

      bool
      _M_apply(_CharT __ch, false_type) const
      {
	auto __c = _M_translator._M_translate(__ch);
	auto __n = _M_translator._M_translate('\n');
	auto __r = _M_translator._M_translate('\r');
	auto __u2028 = _M_translator._M_translate(u'\u2028');
	auto __u2029 = _M_translator._M_translate(u'\u2029');
	return __c != __n &amp;&amp; __c != __r &amp;&amp; __c != __u2028 &amp;&amp; __c != __u2029;
      }

      _TransT _M_translator;
    };

  template&lt;typename _TraitsT, bool __icase, bool __collate&gt;
    struct _CharMatcher
    {
      typedef _RegexTranslator&lt;_TraitsT, __icase, __collate&gt; _TransT;
      typedef typename _TransT::_CharT                       _CharT;

      _CharMatcher(_CharT __ch, const _TraitsT&amp; __traits)
      : _M_translator(__traits), _M_ch(_M_translator._M_translate(__ch))
      { }

      bool
      operator()(_CharT __ch) const
      { return _M_ch == _M_translator._M_translate(__ch); }

      _TransT _M_translator;
      _CharT  _M_ch;
    };

  /// Matches a character range (bracket expression)
  template&lt;typename _TraitsT, bool __icase, bool __collate&gt;
    struct _BracketMatcher
    {
    public:
      typedef _RegexTranslator&lt;_TraitsT, __icase, __collate&gt; _TransT;
      typedef typename _TransT::_CharT                       _CharT;
      typedef typename _TransT::_StrTransT                   _StrTransT;
      typedef typename _TraitsT::string_type                 _StringT;
      typedef typename _TraitsT::char_class_type             _CharClassT;

    public:
      _BracketMatcher(bool __is_non_matching,
		      const _TraitsT&amp; __traits)
      : _M_class_set(0), _M_translator(__traits), _M_traits(__traits),
      _M_is_non_matching(__is_non_matching)
      { }

      bool
      operator()(_CharT __ch) const
      {
	_GLIBCXX_DEBUG_ASSERT(_M_is_ready);
	return _M_apply(__ch, _UseCache());
      }

      void
      _M_add_char(_CharT __c)
      {
	_M_char_set.push_back(_M_translator._M_translate(__c));
	_GLIBCXX_DEBUG_ONLY(_M_is_ready = false);
      }

      _StringT
      _M_add_collate_element(const _StringT&amp; __s)
      {
	auto __st = _M_traits.lookup_collatename(__s.data(),
						 __s.data() + __s.size());
	if (__st.empty())
	  __throw_regex_error(regex_constants::error_collate,
			      &quot;Invalid collate element.&quot;);
	_M_char_set.push_back(_M_translator._M_translate(__st[0]));
	_GLIBCXX_DEBUG_ONLY(_M_is_ready = false);
	return __st;
      }

      void
      _M_add_equivalence_class(const _StringT&amp; __s)
      {
	auto __st = _M_traits.lookup_collatename(__s.data(),
						 __s.data() + __s.size());
	if (__st.empty())
	  __throw_regex_error(regex_constants::error_collate,
			      &quot;Invalid equivalence class.&quot;);
	__st = _M_traits.transform_primary(__st.data(),
					   __st.data() + __st.size());
	_M_equiv_set.push_back(__st);
	_GLIBCXX_DEBUG_ONLY(_M_is_ready = false);
      }

      // __neg should be true for \D, \S and \W only.
      void
      _M_add_character_class(const _StringT&amp; __s, bool __neg)
      {
	auto __mask = _M_traits.lookup_classname(__s.data(),
						 __s.data() + __s.size(),
						 __icase);
	if (__mask == 0)
	  __throw_regex_error(regex_constants::error_collate,
			      &quot;Invalid character class.&quot;);
	if (!__neg)
	  _M_class_set |= __mask;
	else
	  _M_neg_class_set.push_back(__mask);
	_GLIBCXX_DEBUG_ONLY(_M_is_ready = false);
      }

      void
      _M_make_range(_CharT __l, _CharT __r)
      {
	if (__l &gt; __r)
	  __throw_regex_error(regex_constants::error_range,
			      &quot;Invalid range in bracket expression.&quot;);
	_M_range_set.push_back(make_pair(_M_translator._M_transform(__l),
					 _M_translator._M_transform(__r)));
	_GLIBCXX_DEBUG_ONLY(_M_is_ready = false);
      }

      void
      _M_ready()
      {
	std::sort(_M_char_set.begin(), _M_char_set.end());
	auto __end = std::unique(_M_char_set.begin(), _M_char_set.end());
	_M_char_set.erase(__end, _M_char_set.end());
	_M_make_cache(_UseCache());
	_GLIBCXX_DEBUG_ONLY(_M_is_ready = true);
      }

    private:
      // Currently we only use the cache for char
      typedef typename std::is_same&lt;_CharT, char&gt;::type _UseCache;

      static constexpr size_t
      _S_cache_size()
      {
	return 1ul &lt;&lt; (sizeof(_CharT) * __CHAR_BIT__ * int(_UseCache::value));
      }

      struct _Dummy { };
      typedef typename std::conditional&lt;_UseCache::value,
					std::bitset&lt;_S_cache_size()&gt;,
					_Dummy&gt;::type _CacheT;
      typedef typename std::make_unsigned&lt;_CharT&gt;::type _UnsignedCharT;

      bool
      _M_apply(_CharT __ch, false_type) const;

      bool
      _M_apply(_CharT __ch, true_type) const
      { return _M_cache[static_cast&lt;_UnsignedCharT&gt;(__ch)]; }

      void
      _M_make_cache(true_type)
      {
	for (unsigned __i = 0; __i &lt; _M_cache.size(); __i++)
	  _M_cache[__i] = _M_apply(static_cast&lt;_CharT&gt;(__i), false_type());
      }

      void
      _M_make_cache(false_type)
      { }

    private:
      std::vector&lt;_CharT&gt;                       _M_char_set;
      std::vector&lt;_StringT&gt;                     _M_equiv_set;
      std::vector&lt;pair&lt;_StrTransT, _StrTransT&gt;&gt; _M_range_set;
      std::vector&lt;_CharClassT&gt;                  _M_neg_class_set;
      _CharClassT                               _M_class_set;
      _TransT                                   _M_translator;
      const _TraitsT&amp;                           _M_traits;
      bool                                      _M_is_non_matching;
      _CacheT					_M_cache;
#ifdef _GLIBCXX_DEBUG
      bool                                      _M_is_ready = false;
#endif
    };

 //@} regex-detail
} // namespace __detail
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace std

#include &lt;bits/regex_compiler.tcc&gt;
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