Mercurial > octave-antonio
view scripts/strings/index.m @ 20166:196871335aa8
Allow call with empty argument list in strcat related functions (bug #44981)
* libinterp/corefcn/strfns.cc (strvcat): return an empty string for an empty
argument list. Simply dropping the input checking, will return an empty
string. This makes it more consistent with cat(), vertcat, and horzcat()
functions, which return [] for this cases. It makes it easier to support
"strcat (cell{:})" when cell is empty.
* scripts/strings/cstrcat.m, scripts/strings/strcat.m: same as above. But
because [cellstr{:}] when cellstr is empty returns double ([]), we
specifically return "".
author | Carnë Draug <carandraug@octave.org> |
---|---|
date | Fri, 01 May 2015 16:21:39 +0100 |
parents | 9fc020886ae9 |
children | df437a52bcaf |
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## Copyright (C) 1996-2015 Kurt Hornik ## ## 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 ## <http://www.gnu.org/licenses/>. ## -*- texinfo -*- ## @deftypefn {Function File} {} index (@var{s}, @var{t}) ## @deftypefnx {Function File} {} index (@var{s}, @var{t}, @var{direction}) ## Return the position of the first occurrence of the string @var{t} in the ## string @var{s}, or 0 if no occurrence is found. @var{s} may also be a ## string array or cell array of strings. ## ## For example: ## ## @example ## @group ## index ("Teststring", "t") ## @result{} 4 ## @end group ## @end example ## ## If @var{direction} is @qcode{"first"}, return the first element found. ## If @var{direction} is @qcode{"last"}, return the last element found. ## ## @seealso{find, rindex} ## @end deftypefn ## Author: Kurt Hornik <Kurt.Hornik@wu-wien.ac.at> ## Adapted-By: jwe ## This is patterned after the AWK function of the same name. function n = index (s, t, direction = "first") if (nargin < 2 || nargin > 3) print_usage (); endif if (ischar (s)) if (! isrow (s)) s = cellstr (s); # Handle string arrays by conversion to cellstr endif elseif (! iscellstr (s)) error ("index: S must be a string, string array, or cellstr"); endif f = strfind (s, t); if (isempty (f)) f = 0; elseif (iscell (f)) f(cellfun ("isempty", f)) = {0}; endif direction = tolower (direction); if (strcmp (direction, "first")) if (iscell (f)) n = cellfun ("min", f); else n = f(1); endif elseif (strcmp (direction, "last")) if (iscell (f)) n = cellfun ("max", f); else n = f(end); endif else error ('index: DIRECTION must be either "first" or "last"'); endif endfunction %!assert (index ("foobarbaz", "b"), 4) %!assert (index ("foobarbaz", "z"), 9) %!assert (index ("astringbstringcstring", "s"), 2) %!assert (index ("astringbstringcstring", "st"), 2) %!assert (index ("astringbstringcstring", "str"), 2) %!assert (index ("astringbstringcstring", "string"), 2) %!assert (index ("abc---", "abc+++"), 0) ## test everything out in reverse %!assert (index ("astringbstringcstring", "s", "last"), 16) %!assert (index ("astringbstringcstring", "st", "last"), 16) %!assert (index ("astringbstringcstring", "str", "last"), 16) %!assert (index ("astringbstringcstring", "string", "last"), 16) %!assert (index ("abc---", "abc+++", "last"), 0) %!test %! str = char ("Hello", "World", "Goodbye", "World"); %! assert (index (str, "o"), [5; 2; 2; 2]); %! assert (index (str, "o", "last"), [5; 2; 3; 2]); %! str = cellstr (str); %! assert (index (str, "o"), [5; 2; 2; 2]); %! assert (index (str, "o", "last"), [5; 2; 3; 2]); ## Test input validation %!error index () %!error index ("a") %!error index ("a", "b", "first", "d") %!error index (1, "bar") %!error index ("foo", "bar", 3)