stack.hh

GNU的词法/语法分析器bison源码

/* A Bison parser, made by GNU Bison 2.1.  */

/* stack handling for Bison C++ parsers,
   Copyright (C) 2002, 2003, 2004, 2005 Free Software Foundation, Inc.

   This program 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 2, or (at your option)
   any later version.

   This program 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.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street, Fifth Floor,
   Boston, MA 02110-1301, USA.  */

#ifndef BISON_STACK_HH
# define BISON_STACK_HH

#include <deque>

namespace yy
{
  template <class T, class S = std::deque<T> >
  class stack
  {
  public:

    // Hide our reversed order.
    typedef typename S::reverse_iterator iterator;
    typedef typename S::const_reverse_iterator const_iterator;

    stack () : seq_ ()
    {
    }

    stack (unsigned int n) : seq_ (n)
    {
    }

    inline
    T&
    operator [] (unsigned int i)
    {
      return seq_[i];
    }

    inline
    const T&
    operator [] (unsigned int i) const
    {
      return seq_[i];
    }

    inline
    void
    push (const T& t)
    {
      seq_.push_front (t);
    }

    inline
    void
    pop (unsigned int n = 1)
    {
      for (; n; --n)
	seq_.pop_front ();
    }

    inline
    unsigned int
    height () const
    {
      return seq_.size ();
    }

    inline const_iterator begin () const { return seq_.rbegin (); }
    inline const_iterator end () const { return seq_.rend (); }

  private:

    S seq_;
  };

  /// Present a slice of the top of a stack.
  template <class T, class S = stack<T> >
  class slice
  {
  public:

    slice (const S& stack,
	   unsigned int range) : stack_ (stack),
				 range_ (range)
    {
    }

    inline
    const T&
    operator [] (unsigned int i) const
    {
      return stack_[range_ - i];
    }

  private:

    const S& stack_;
    unsigned int range_;
  };
}

#endif // not BISON_STACK_HH