########################################################################
##
## Copyright (C) 2016-2021 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.
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## 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.
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## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
## GNU General Public License for more details.
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## along with Octave; see the file COPYING.  If not, see
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########################################################################

## -*- texinfo -*-
## @deftypefn {} {@var{varargout} =} __default__input__ (@var{def_val}, @var{varargin})
## Check if the input arguments of a function are empty or missing.
## If they are, use default values.
##
## The input arguments are:
##
## @itemize @minus
## @item @var{def_val} is a cell array that contains the values to use
## as default.
##
## @item @var{varargin} are the input arguments
## @end itemize
##
## The output arguments are:
##
## @itemize @minus
## @item @var{varargout} all input arguments completed with default
## values for empty or omitted parameters.
##
## @end itemize
##
## @end deftypefn


function [varargout] = __default__input__ (def_val, varargin)

  m = length (def_val);
  n = length (varargin);

  for i = 1:m
    if (n < i || isempty (varargin{i}))
      varargout{i} = def_val{i};
    else
      varargout{i} = varargin{i};
    endif
  endfor

endfunction