########################################################################
##
## Copyright (C) 2019-2024 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
## (at your option) any later version.
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## 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.
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## You should have received a copy of the GNU General Public License
## along with Octave; see the file COPYING.  If not, see
## <https://www.gnu.org/licenses/>.
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########################################################################

## -*- texinfo -*-
## @deftypefn {} {} mustBeNonempty (@var{x})
##
## Require that input @var{x} is nonempty.
##
## Raise an error if the input @var{x} is empty, as determined by
## @code{isempty (@var{x})}.
##
## @seealso{mustBeMember, mustBeNonzero, isempty}
## @end deftypefn

function mustBeNonempty (x)

  if (nargin < 1)
    print_usage ();
  endif

  if (isempty (x))
    label = inputname (1);
    if (isempty (label))
      label = "input";
    endif
    error ("%s must not be empty", label);
  endif

endfunction


%!test
%! mustBeNonempty (42);
%! mustBeNonempty ("Hello");
%! mustBeNonempty (Inf);
%! mustBeNonempty (NaN);

%!error <Invalid call> mustBeNonempty ()
%!error <input must not be empty> mustBeNonempty ([])
%!error <input must not be empty> mustBeNonempty ('')
%!error <input must not be empty> mustBeNonempty (reshape ([], [0 3 3 3]))
