/*

Copyright (C) 1996-2017 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 3 of the License, 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, see
<http://www.gnu.org/licenses/>.

*/

#if ! defined (octave_oct_lvalue_h)
#define octave_oct_lvalue_h 1

#include "octave-config.h"

class octave_value;
class octave_value_list;

#include <string>

#include "ovl.h"
#include "symtab.h"

class
octave_lvalue
{
public:

  octave_lvalue (const octave::symbol_record& s
                   = octave::symbol_record ())
    : sym (s), black_hole (false), type (), idx (), nel (1)
  { }

  octave_lvalue (const octave_lvalue& vr)
    : sym (vr.sym), black_hole (vr.black_hole), type (vr.type), idx (vr.idx), nel (vr.nel)
  { }

  octave_lvalue& operator = (const octave_lvalue& vr)
  {
    if (this != &vr)
      {
        sym = vr.sym;
        black_hole = vr.black_hole;
        type = vr.type;
        idx = vr.idx;
        nel = vr.nel;
      }

    return *this;
  }

  ~octave_lvalue (void) = default;

  bool is_black_hole (void) const { return black_hole; }

  void mark_black_hole (void) { black_hole = true; }

  bool is_defined (void) const
  {
    return ! is_black_hole () && sym.is_defined ();
  }

  bool is_undefined (void) const
  {
    return is_black_hole () || sym.is_undefined ();
  }

  bool isstruct (void) const { return value().isstruct (); }

  void define (const octave_value& v) { sym.assign (v); }

  void assign (octave_value::assign_op, const octave_value&);

  void numel (octave_idx_type n) { nel = n; }

  octave_idx_type numel (void) const { return nel; }

  void set_index (const std::string& t, const std::list<octave_value_list>& i);

  void clear_index (void) { type = ""; idx.clear (); }

  std::string index_type (void) const { return type; }

  bool index_is_empty (void) const;

  void do_unary_op (octave_value::unary_op op);

  octave_value value (void) const;

private:

  octave::symbol_record sym;

  bool black_hole;

  std::string type;

  std::list<octave_value_list> idx;

  octave_idx_type nel;
};

#endif