v4 parser: adding stack.hh for people who have an old bison

git-svn-id: https://www.dynare.org/svn/dynare/dynare_v4@1175 ac1d8469-bf42-47a9-8791-bf33cf982152

parser.src/include/stack.hh

+/* A Bison parser, made by GNU Bison 2.3.  */
+
+/* Stack handling for Bison parsers in C++
+
+   Copyright (C) 2002, 2003, 2004, 2005, 2006 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.  */
+
+/* As a special exception, you may create a larger work that contains
+   part or all of the Bison parser skeleton and distribute that work
+   under terms of your choice, so long as that work isn't itself a
+   parser generator using the skeleton or a modified version thereof
+   as a parser skeleton.  Alternatively, if you modify or redistribute
+   the parser skeleton itself, you may (at your option) remove this
+   special exception, which will cause the skeleton and the resulting
+   Bison output files to be licensed under the GNU General Public
+   License without this special exception.
+
+   This special exception was added by the Free Software Foundation in
+   version 2.2 of Bison.  */
+
+#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