########################################################################
##
## Copyright (C) 2021 The Octave Project Developers
##
## See the file COPYRIGHT.md in the top-level directory of this
## distribution or <https://octave.org/copyright/>.
##
## 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
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########################################################################

## -*- texinfo -*-
## @deftypefn  {} {@var{val} =} disable_diagonal_matrix ()
## @deftypefnx {} {@var{old_val} =} disable_diagonal_matrix (@var{new_val})
## @deftypefnx {} {} disable_diagonal_matrix (@var{new_val}, "local")
## Query or set whether storing diagonal matrices in a special space-efficient
## format is disabled.
## 
## The default value is false.  If this option is set to true, Octave will
## store ranges as full matrices.
## 
## When called from inside a function with the @qcode{"local"} option, the
## setting is changed locally for the function and any subroutines it calls.
## The original setting is restored when exiting the function.
## @seealso{disable_diagonal_matrix, disable_permutation_matrix}
## @end deftypefn

## FIXME: DEPRECATED: Remove in version 9.

function retval = disable_diagonal_matrix (varargin)

  persistent warned = false;
  if (! warned)
    warned = true;
    warning ("Octave:deprecated-function",
             "disable_diagonal_matrix is obsolete and will be removed from a future version of Octave, please use optimize_diagonal_matrix instead\n");
  endif

  if (nargin == 0)
    retval = ! optimize_diagonal_matrix ();
  elseif (nargout == 0)
    optimize_diagonal_matrix (! varargin{1}, varargin{2:end});
  else
    retval = ! optimize_diagonal_matrix (! varargin{1}, varargin{2:end});
  endif

endfunction