Mercurial > octave
view scripts/miscellaneous/nargoutchk.m @ 31602:16fb0e3e6aab
maint: Merge stable to default.
author | John W. Eaton <jwe@octave.org> |
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date | Thu, 01 Dec 2022 15:04:44 -0500 |
parents | 5d3faba0342e |
children | 597f3ee61a48 |
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######################################################################## ## ## Copyright (C) 2008-2022 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. ## ## 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 ## <https://www.gnu.org/licenses/>. ## ######################################################################## ## -*- texinfo -*- ## @deftypefn {} {} nargoutchk (@var{minargs}, @var{maxargs}) ## @deftypefnx {} {@var{msgstr} =} nargoutchk (@var{minargs}, @var{maxargs}, @var{nargs}) ## @deftypefnx {} {@var{msgstr} =} nargoutchk (@var{minargs}, @var{maxargs}, @var{nargs}, "string") ## @deftypefnx {} {@var{msgstruct} =} nargoutchk (@var{minargs}, @var{maxargs}, @var{nargs}, "struct") ## Check for correct number of output arguments. ## ## In the first form, return an error if the number of arguments is not between ## @var{minargs} and @var{maxargs}. Otherwise, do nothing. Note that this ## function evaluates the value of @code{nargout} on the caller so its value ## must have not been tampered with. ## ## Both @var{minargs} and @var{maxargs} must be numeric scalars. Zero, Inf, ## and negative are all valid, and they can have the same value. ## ## For backwards compatibility, the other forms return an appropriate error ## message string (or structure) if the number of outputs requested is ## invalid. ## ## This is useful for checking to that the number of output arguments supplied ## to a function is within an acceptable range. ## @seealso{narginchk, error, nargout, nargin} ## @end deftypefn function msg = nargoutchk (minargs, maxargs, nargs, outtype) ## Before Matlab 2011b, nargoutchk would return an error message (just the ## message in a string). With 2011b, it no longer returns anything, it ## simply gives an error if the args number is incorrect. ## To try to keep compatibility with both versions, check nargout and nargin ## to guess if the caller is expecting a value (old syntax) or none ## (new syntax). if (nargout == 1 && (nargin == 3 || nargin == 4)) if (minargs > maxargs) error ("nargoutchk: MINARGS must be <= MAXARGS"); elseif (nargin == 3) outtype = "string"; elseif (! any (strcmpi (outtype, {"string" "struct"}))) error ("nargoutchk: output type must be either string or struct"); elseif (! (isscalar (minargs) && isscalar (maxargs) && isscalar (nargs))) error ("nargoutchk: MINARGS, MAXARGS, and NARGS must be scalars"); endif msg = struct ("message", "", "identifier", ""); if (nargs < minargs) msg.message = "not enough output arguments"; msg.identifier = "Octave:nargoutchk:not-enough-outputs"; elseif (nargs > maxargs) msg.message = "too many output arguments"; msg.identifier = "Octave:nargoutchk:too-many-outputs"; endif if (strcmpi (outtype, "string")) msg = msg.message; elseif (isempty (msg.message)) ## Compatibility: Matlab returns a 0x1 empty struct when nargoutchk passes msg = resize (msg, 0, 1); endif elseif (nargout == 0 && nargin == 2) if (! isnumeric (minargs) || ! isscalar (minargs)) error ("nargoutchk: MINARGS must be a numeric scalar"); elseif (! isnumeric (maxargs) || ! isscalar (maxargs)) error ("nargoutchk: MAXARGS must be a numeric scalar"); elseif (minargs > maxargs) error ("nargoutchk: MINARGS cannot be larger than MAXARGS"); endif args = evalin ("caller", "nargout;"); if (args < minargs) error ("nargoutchk: Not enough output arguments"); elseif (args > maxargs) error ("nargoutchk: Too many output arguments"); endif else print_usage (); endif endfunction %!shared stnul, stmin, stmax %! stnul = resize (struct ("message", "", "identifier", ""), 0, 1); %! stmin = struct ("message", "not enough output arguments", %! "identifier", "Octave:nargoutchk:not-enough-outputs"); %! stmax = struct ("message", "too many output arguments", %! "identifier", "Octave:nargoutchk:too-many-outputs"); %!assert (nargoutchk (0, 1, 0), "") %!assert (nargoutchk (0, 1, 1), "") %!assert (nargoutchk (1, 1, 0), "not enough output arguments") %!assert (nargoutchk (0, 1, 2), "too many output arguments") %!assert (nargoutchk (0, 1, 2, "string"), "too many output arguments") ## Struct outputs %!assert (nargoutchk (0, 1, 0, "struct"), stnul) %!assert (nargoutchk (0, 1, 1, "struct"), stnul) %!assert (nargoutchk (1, 1, 0, "struct"), stmin) %!assert (nargoutchk (0, 1, 2, "struct"), stmax)