update packages

[CreaPhase.git] / octave_packages / m / strings / strchr.m

diff --git a/octave_packages/m/strings/strchr.m b/octave_packages/m/strings/strchr.m
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+## Copyright (C) 2008-2012 Jaroslav Hajek
+##
+## 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} {@var{idx} =} strchr (@var{str}, @var{chars})
+## @deftypefnx {Function File} {@var{idx} =} strchr (@var{str}, @var{chars}, @var{n})
+## @deftypefnx {Function File} {@var{idx} =} strchr (@var{str}, @var{chars}, @var{n}, @var{direction})
+## @deftypefnx {Function File} {[@var{i}, @var{j}] =} strchr (@dots{})
+## Search for the string @var{str} for occurrences of characters from
+## the set @var{chars}.  The return value(s), as well as the @var{n} and
+## @var{direction} arguments behave identically as in @code{find}.
+##
+## This will be faster than using regexp in most cases.
+##
+## @seealso{find}
+## @end deftypefn
+
+function varargout = strchr (str, chars, varargin)
+
+  if (nargin < 2)
+    print_usage ();
+  elseif (! ischar (str))
+    error ("strchr: STR argument must be a string or string array");
+  elseif (! ischar (chars))
+    error ("strchr: CHARS argument must be a string");
+  endif
+
+  if (isempty (chars))
+    mask = false (size (str));
+  elseif (length (chars) <= 4)
+    ## With a few characters, it pays off to build the mask incrementally.
+    ## We do it via a for loop to save memory.
+    mask = str == chars(1);
+    for i = 2:length (chars)
+      mask |= str == chars(i);
+    endfor
+  else
+    ## Index the str into a mask of valid values.
+    ## This is slower than it could be because of the +1 issue.
+    f = false (256, 1);
+    f(uint8(chars)+1) = true;
+    ## Default goes via double -- unnecessarily long.
+    si = uint32 (str);
+    ## in-place is faster than str+1
+    ++si;
+    mask = reshape (f(si), size (str));
+  endif
+
+  varargout = cell (1, nargout);
+  varargout{1} = [];
+  [varargout{:}] = find (mask, varargin{:});
+
+endfunction
+
+
+%!assert (strchr ("Octave is the best software", ""), zeros (1,0))
+%!assert (strchr ("Octave is the best software", "best"), [3, 6, 9, 11, 13, 15, 16, 17, 18, 20, 23, 27])
+%!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])
+
+%% Test input validation
+%!error strchr ()
+%!error strchr (1)
+%!error <STR argument must be a string> strchr (1, "aeiou")
+%!error <CHARS argument must be a string> strchr ("aeiou", 1)
+