Mercurial > hg > octave-lyh
annotate scripts/strings/strchr.m @ 11260:fd18ba11af57
Extra tests in strchr
| author | Kim Hansen <kim@ange.dk> |
|---|---|
| date | Wed, 17 Nov 2010 04:16:59 -0500 |
| parents | be55736a0783 |
| children | 9c19b450b254 |
| rev | line source |
|---|---|
| 8920 | 1 ## Copyright (C) 2008, 2009 Jaroslav Hajek |
| 8552 | 2 ## |
| 3 ## This file is part of Octave. | |
| 4 ## | |
| 5 ## Octave is free software; you can redistribute it and/or modify it | |
| 6 ## under the terms of the GNU General Public License as published by | |
| 7 ## the Free Software Foundation; either version 3 of the License, or (at | |
| 8 ## your option) any later version. | |
| 9 ## | |
| 10 ## Octave is distributed in the hope that it will be useful, but | |
| 11 ## WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 12 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 13 ## General Public License for more details. | |
| 14 ## | |
| 15 ## You should have received a copy of the GNU General Public License | |
| 16 ## along with Octave; see the file COPYING. If not, see | |
| 17 ## <http://www.gnu.org/licenses/>. | |
| 18 | |
| 19 ## -*- texinfo -*- | |
|
10793
be55736a0783
Grammarcheck the documentation from m-files.
Rik <octave@nomad.inbox5.com>
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10408
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20 ## @deftypefn {Function File} {@var{idx} =} strchr (@var{str}, @var{chars}) |
| 8552 | 21 ## @deftypefnx {Function File} {@var{idx} =} strchr (@var{str}, @var{chars}, @var{n}) |
| 8830 | 22 ## @deftypefnx {Function File} {@var{idx} =} strchr (@var{str}, @var{chars}, @var{n}, @var{direction}) |
|
10793
be55736a0783
Grammarcheck the documentation from m-files.
Rik <octave@nomad.inbox5.com>
parents:
10408
diff
changeset
|
23 ## Search for the string @var{str} for occurrences of characters from the set |
|
be55736a0783
Grammarcheck the documentation from m-files.
Rik <octave@nomad.inbox5.com>
parents:
10408
diff
changeset
|
24 ## @var{chars}. |
| 8552 | 25 ## The return value, as well as the @var{n} and @var{direction} arguments behave |
| 26 ## identically as in @code{find}. | |
| 27 ## | |
| 28 ## This will be faster than using regexp in most cases. | |
| 29 ## | |
| 30 ## @seealso{find} | |
| 8715 | 31 ## @end deftypefn |
| 8552 | 32 |
| 33 function varargout = strchr (str, chars, varargin) | |
| 34 if (nargin < 2 || ! ischar (str) || ! ischar (chars)) | |
| 35 print_usage (); | |
| 36 endif | |
| 10408 | 37 if (isempty (chars)) |
| 38 mask = false (size (str)); | |
| 39 elseif (length (chars) <= 6) | |
| 40 ## With a few characters, it pays off to build the mask incrementally. | |
| 41 ## We do it via a for loop to save memory. | |
| 42 mask = str == chars(1); | |
| 43 for i = 2:length (chars) | |
| 44 mask |= str == chars(i); | |
| 45 endfor | |
| 46 else | |
| 47 ## Index the str into a mask of valid values. This is slower than it could be | |
| 48 ## because of the +1 issue. | |
| 49 f = false (1, 256); | |
| 50 f(chars + 1) = true; | |
| 51 si = uint32 (str); # default goes via double - unnecessarily long. | |
| 52 ++si; # in-place | |
| 53 mask = reshape (f(si), size (str)); | |
| 54 endif | |
| 8552 | 55 varargout = cell (1, nargout); |
| 56 varargout{1} = []; | |
| 10408 | 57 [varargout{:}] = find (mask, varargin{:}); |
| 8552 | 58 endfunction |
| 59 | |
| 11260 | 60 %!assert(strchr("Octave is the best software",""),zeros(1,0)) |
| 8552 | 61 %!assert(strchr("Octave is the best software","best"),[3, 6, 9, 11, 13, 15, 16, 17, 18, 20, 23, 27]) |
| 11260 | 62 %!assert(strchr("Octave is the best software","software"),[3, 4, 6, 9, 11, 13, 16, 17, 18, 20, 21, 22, 23, 24, 25, 26, 27]) |
| 63 |