/*

Copyright (C) 1996, 1997 John W. Eaton

This file is part of Octave.

Octave 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.

Octave 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 Octave; see the file COPYING.  If not, write to the Free
Software Foundation, 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

*/

#if !defined (octave_tree_cmd_h)
#define octave_tree_cmd_h 1

#if defined (__GNUG__)
#pragma interface
#endif

#include <string>

class tree_walker;

#include "pt.h"

// A base class for commands.

class
tree_command : public tree
{
public:

  tree_command (int l = -1, int c = -1)
    : tree (l, c) { }

  virtual ~tree_command (void) { }

  virtual void eval (void) = 0;

private:

  // No copying!

  tree_command (const tree_command&);

  tree_command& operator = (const tree_command&);
};

// No-op.

class
tree_no_op_command : public tree_command
{
public:

  tree_no_op_command (const string& cmd = "no_op", int l = -1, int c = -1)
    : tree_command (l, c), orig_cmd (cmd) { }

  ~tree_no_op_command (void) { }

  void eval (void) { }

  void accept (tree_walker& tw);

  string original_command (void) { return orig_cmd; }

private:

  string orig_cmd;

  // No copying!

  tree_no_op_command (const tree_no_op_command&);

  tree_no_op_command& operator = (const tree_no_op_command&);
};

#endif

/*
;;; Local Variables: ***
;;; mode: C++ ***
;;; End: ***
*/