/*

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_pt_assign_h)
#define octave_pt_assign_h 1

#include "octave-config.h"

#include <iosfwd>
#include <string>

class octave_value;
class octave_value_list;
class octave_lvalue;

#include "ov.h"
#include "pt-exp.h"
#include "pt-walk.h"
#include "symtab.h"

namespace octave
{
  class tree_argument_list;

  // Simple assignment expressions.

  class tree_simple_assignment : public tree_expression
  {
  public:

    tree_simple_assignment (bool plhs = false, int l = -1, int c = -1,
                            octave_value::assign_op t = octave_value::op_asn_eq)
      : tree_expression (l, c), lhs (nullptr), rhs (nullptr), preserve (plhs),
        ans_ass (), etype (t) { }

    tree_simple_assignment (tree_expression *le, tree_expression *re,
                            bool plhs = false, int l = -1, int c = -1,
                            octave_value::assign_op t = octave_value::op_asn_eq);

    // No copying!

    tree_simple_assignment (const tree_simple_assignment&) = delete;

    tree_simple_assignment& operator = (const tree_simple_assignment&) = delete;

    ~tree_simple_assignment (void);

    bool has_magic_end (void) const { return (rhs && rhs->has_magic_end ()); }

    bool rvalue_ok (void) const { return true; }

    bool is_assignment_expression (void) const { return true; }

    std::string oper (void) const;

    tree_expression * left_hand_side (void) { return lhs; }

    tree_expression * right_hand_side (void) { return rhs; }

    tree_expression * dup (symbol_scope& scope) const;

    void accept (tree_walker& tw)
    {
      tw.visit_simple_assignment (*this);
    }

    octave_value::assign_op op_type (void) const { return etype; }

  private:

    void do_assign (octave_lvalue& ult, const octave_value_list& args,
                    const octave_value& rhs_val);

    void do_assign (octave_lvalue& ult, const octave_value& rhs_val);

    // The left hand side of the assignment.
    tree_expression *lhs;

    // The right hand side of the assignment.
    tree_expression *rhs;

    // True if we should not delete the lhs.
    bool preserve;

    // True if this is an assignment to the automatic variable ans.
    bool ans_ass;

    // The type of the expression.
    octave_value::assign_op etype;
  };

  // Multi-valued assignment expressions.

  class tree_multi_assignment : public tree_expression
  {
  public:

    tree_multi_assignment (bool plhs = false, int l = -1, int c = -1)
      : tree_expression (l, c), lhs (nullptr), rhs (nullptr), preserve (plhs)
      { }

    tree_multi_assignment (tree_argument_list *lst, tree_expression *r,
                           bool plhs = false, int l = -1, int c = -1);

    // No copying!

    tree_multi_assignment (const tree_multi_assignment&) = delete;

    tree_multi_assignment& operator = (const tree_multi_assignment&) = delete;

    ~tree_multi_assignment (void);

    bool has_magic_end (void) const { return (rhs && rhs->has_magic_end ()); }

    bool is_assignment_expression (void) const { return true; }

    bool rvalue_ok (void) const { return true; }

    std::string oper (void) const;

    tree_argument_list * left_hand_side (void) { return lhs; }

    tree_expression * right_hand_side (void) { return rhs; }

    tree_expression * dup (symbol_scope& scope) const;

    void accept (tree_walker& tw)
    {
      tw.visit_multi_assignment (*this);
    }

    octave_value::assign_op op_type (void) const
    { return octave_value::op_asn_eq; }

  private:

    // The left hand side of the assignment.
    tree_argument_list *lhs;

    // The right hand side of the assignment.
    tree_expression *rhs;

    // True if we should not delete the lhs.
    bool preserve;
  };
}

#if defined (OCTAVE_USE_DEPRECATED_FUNCTIONS)

OCTAVE_DEPRECATED (4.4, "use 'octave::tree_simple_assignment' instead")
typedef octave::tree_simple_assignment tree_simple_assignment;

OCTAVE_DEPRECATED (4.4, "use 'octave::tree_multi_assignment' instead")
typedef octave::tree_multi_assignment tree_multi_assignment;

#endif

#endif