view scripts/strings/cstrcat.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
line wrap: on
line source

## Copyright (C) 1994-2015 John W. Eaton
##
## 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} {} cstrcat (@var{s1}, @var{s2}, @dots{})
## Return a string containing all the arguments concatenated
## horizontally.  Trailing white space is preserved.  For example:
##
## @example
## @group
## cstrcat ("ab   ", "cd")
##       @result{} "ab   cd"
## @end group
## @end example
##
## @example
## @group
## s = [ "ab"; "cde" ];
## cstrcat (s, s, s)
##       @result{} "ab ab ab "
##          "cdecdecde"
## @end group
## @end example
## @seealso{strcat, char, strvcat}
## @end deftypefn

## Author: jwe

function st = cstrcat (varargin)

  if (nargin == 0)
    ## Special because if varargin is empty, iscellstr still returns
    ## true but then "[varargin{:}]" would be of class double.
    st = "";
  elseif (! iscellstr (varargin))
    st = [varargin{:}];
  else
    error ("cstrcat: expecting arguments to character strings");
  endif

endfunction


## Test the dimensionality
## 1d
%!assert (cstrcat ("ab ", "ab "), "ab ab ")
## 2d
%!assert (cstrcat (["ab ";"cde"], ["ab ";"cde"]), ["ab ab ";"cdecde"])

%!assert (cstrcat ("foo", "bar"), "foobar")
%!assert (cstrcat (["a"; "bb"], ["foo"; "bar"]), ["a foo"; "bbbar"])

%!assert (cstrcat (), "")

## Test input validation
%!error cstrcat (1, 2)