Mercurial > octave
view scripts/miscellaneous/inputname.m @ 31235:b542b88ad3b6
maint: Use space between function name and '(' in sparse-xpow.cc.
* sparse-xpow.cc: Use space between function name and '(' in sparse-xpow.cc.
author | Rik <rik@octave.org> |
---|---|
date | Tue, 20 Sep 2022 14:43:56 -0700 |
parents | e1788b1a315f |
children | 597f3ee61a48 |
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######################################################################## ## ## Copyright (C) 2004-2022 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/>. ## ######################################################################## ## ## Original version by Paul Kienzle distributed as free software in the ## public domain. ## -*- texinfo -*- ## @deftypefn {} {@var{namestr} =} inputname (@var{n}) ## @deftypefnx {} {@var{namestr} =} inputname (@var{n}, @var{ids_only}) ## Return the name of the @var{n}-th argument to the calling function. ## ## If the argument is not a simple variable name, return an empty string. ## Examples which will return @qcode{""} are numbers (@code{5.1}), ## expressions (@code{@var{y}/2}), and cell or structure indexing ## (@code{@var{c}@{1@}} or @code{@var{s}.@var{field}}). ## ## @code{inputname} is only useful within a function. When used at the command ## line or within a script it always returns an empty string. ## ## By default, return an empty string if the @var{n}-th argument is not a valid ## variable name. If the optional argument @var{ids_only} is false, return the ## text of the argument even if it is not a valid variable name. This is an ## Octave extension that allows the programmer to view exactly how the function ## was invoked even when the inputs are complex expressions. ## @seealso{nargin, narginchk} ## @end deftypefn ## FIXME: Actually, it probably *isn't* worth fixing, but there are small ## differences between Octave and Matlab. ## ## 1) When called from the top-level or a script, Matlab throws an error ## ## inputname (1) % at command prompt ## % Octave returns "", Matlab throws an error ## ## 2) cell or struct indexing causes all further names to be returned as "" ## ## c = {'a', 'b'} ## y = 1; z = 2; ## fcn (c, y, z) ## % inputname() would return 'c', 'y', 'z' for the inputs. ## fcn (c{1}, y, z) ## % inputname() would return '', '', '' for the inputs. ## ## 3) If inputname is not called from a function, Matlab walks up the stack ## until it finds some valid code and then works from there. This could ## be relevant for mex files or anonymous functions. ## ## f = @(x) inputname (x); ## a = 1:4; ## arrayfun (fn, a, 'uniformoutput', false) ## % output is {'fn', 'a', '', ''} function namestr = inputname (n, ids_only = true) if (nargin < 1) print_usage (); endif if (! isscalar (n) || ! isindex (n)) error ("inputname: N must be a scalar index"); endif try namestr = evalin ("caller", sprintf ("__varval__ ('.argn.'){%d}", n)); catch namestr = ""; return; end_try_catch ## For compatibility with Matlab, return empty string if argument name is ## not a valid identifier. if (ids_only && ! isvarname (namestr)) namestr = ""; elseif (ids_only) ## More complicated checking is required to verify name (bug #59103). ## NAME may be text, like "Inf", which is an acceptable variable name ## that passes isvarname(), but that does not mean it is an actual ## variable name, rather than a function or IEEE number. try v = evalin ("caller", sprintf ("evalin ('caller', '__varval__ (\"%s\")')", namestr)); catch namestr = ""; end_try_catch endif endfunction %!function name = __iname1__ (arg1, arg2, arg3) %! name = inputname (1); %!endfunction %!function name = __iname1_ID__ (arg1, arg2, arg3) %! name = inputname (1, false); %!endfunction %!function name = __iname2__ (arg1, arg2, arg3) %! name = inputname (2); %!endfunction %!function names = __iname3__ (arg1, arg2, arg3) %! names = cell (1, 3); %! for i = 1:3 %! names{i} = inputname (i); %! endfor %!endfunction %!test %! assert (__iname1__ ('xvar'), ""); %! xvar = 1; %! assert (__iname1__ (xvar), "xvar"); %!test %! xvar = 1; yvar = 2; %! assert (__iname2__ (xvar), ""); %! assert (__iname2__ (xvar, yvar), "yvar"); %!test %! xvar = 1; yvar = 2; %! assert (__iname3__ (xvar), {"xvar", "", ""}); %! assert (__iname3__ (xvar, yvar), {"xvar", "yvar", ""}); %! assert (__iname3__ (xvar, 3, yvar), {"xvar", "", "yvar"}); ## Test numbers, expressions, indexing operations %!test %! assert (__iname1__ (1.0), ""); %! x = 1; %! assert (__iname1__ (x / 2), ""); %! assert (__iname1__ (Inf), ""); %!test %! assert (__iname1_ID__ (1.0), "1.0"); %! x = 1; %! assert (__iname1_ID__ (x / 2), "x / 2"); %! assert (__iname1_ID__ (Inf), "Inf"); %!error <Invalid call> inputname () %!error <N must be a scalar> inputname (ones (2,2)) %!error <N must be a scalar index> inputname (-1)