Mercurial > octave-antonio
view scripts/strings/strtrunc.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) 2006-2015 William Poetra Yoga Hadisoeseno ## ## 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} {} strtrunc (@var{s}, @var{n}) ## Truncate the character string @var{s} to length @var{n}. If @var{s} ## is a character matrix, then the number of columns is adjusted. ## If @var{s} is a cell array of strings, then the operation is performed ## on each cell element and the new cell array is returned. ## @end deftypefn function s = strtrunc (s, n) if (nargin != 2) print_usage (); endif n = fix (n); if (! isscalar (n) || n < 0) error ("strtrunc: length N must be a positive integer (N >= 0)"); endif if (ischar (s)) if (n < columns (s)) s = s(:, 1:n); endif elseif (iscellstr (s)) ## Convoluted approach converts cellstr to char matrix, trims the character ## matrix using indexing, and then converts back to cellstr with mat2cell. ## This approach is 24X faster than using cellfun with call to strtrunc idx = cellfun ("size", s, 2) > n; rows = cellfun ("size", s(idx), 1); if (! isempty (rows)) s(idx) = mat2cell (char (s(idx))(:, 1:n), rows); endif else error ("strtrunc: S must be a character string or a cell array of strings"); endif endfunction %!assert (strtrunc ("abcdefg", 4), "abcd") %!assert (strtrunc ("abcdefg", 10), "abcdefg") %!assert (strtrunc (char ("abcdef", "fedcba"), 3), ["abc"; "fed"]) %!assert (strtrunc ({"abcdef", "fedcba"}, 3), {"abc", "fed"}) %!assert (strtrunc ({"", "1", "21", "321"}, 1), {"", "1", "2", "3"}) %!assert (strtrunc ({"1", "", "2"}, 1), {"1", "", "2"}) %!test %! cstr = {"line1"; ["line2"; "line3"]; "line4"}; %! y = strtrunc (cstr, 4); %! assert (size (y), [3, 1]); %! assert (size (y{2}), [2, 4]); %! assert (y{2}, repmat ("line", 2, 1)); ## Test input validation %!error strtrunc () %!error strtrunc ("abcd") %!error strtrunc ("abcd", 4, 5) %!error <N must be a positive integer> strtrunc ("abcd", ones (2,2)) %!error <N must be a positive integer> strtrunc ("abcd", -1) %!error <S must be a character string or a cell array of strings> strtrunc (1, 1)