# HG changeset patch
# User Ben Abbott <bpabbott@mac.com>
# Date 1287366295 14400
# Node ID eab173e1e80c93e9332499312a67d5570356fcfe
# Parent  1f9ab076f5f773c1e669ea085a55deda4a0f8beb
untabify.m: New function to untabify text.

diff --git a/scripts/ChangeLog b/scripts/ChangeLog
--- a/scripts/ChangeLog
+++ b/scripts/ChangeLog
@@ -1,3 +1,7 @@
+2010-10-18  Ben Abbott <bpabbott@mac.com>
+
+	* strings/untabify.m: New function to untabify text.
+
 2010-10-17  Ben Abbott <bpabbott@mac.com>
 
 	* plot/mesh.m, plot/surf.m: Include the 4th input (color) in the
diff --git a/scripts/strings/untabify.m b/scripts/strings/untabify.m
new file mode 100644
--- /dev/null
+++ b/scripts/strings/untabify.m
@@ -0,0 +1,115 @@
+## Copyright (C) 2010 Ben Abbott
+## 
+## 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 2 of the License, or (at 
+## your option) any later version.
+## 
+## This program 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} untabify (@var{t})
+## @deftypefnx {Function file} untabify (@var{t}, @var{tw})
+## @deftypefnx {Function file} untabify (@var{t}, @var{tw}, @var{deblank})
+## Replace TAB characters in @var{t}, with spaces.
+## The tab width is specified by @var{tw}, or defaults to eight.
+## The input, @var{t}, may be either a 2D character array, or a cell
+## array of character strings.  The output is the same class
+## as the input.
+##
+## If the optional argument @var{deblank} is true, then the spaces will
+## be removed from the end of the character data.
+##
+## The following example reads a file and writes an untabified version
+## of the same file with trailing spaces stripped.
+##
+## @example
+## @group
+## fid = fopen ("tabbed_script.m");
+## text = char (fread (fid, "uchar")');
+## fclose (fid);
+## fid = fopen ("untabified_script.m", "w");
+## text = untabify (strsplit (text, "\n"), 8, true);
+## fprintf (fid, "%s\n", text{:});
+## fclose (fid);
+## @end group
+## @end example
+##
+## @seealso{strjust, strsplit, deblank}
+## @end deftypefn
+
+## Author: Ben Abbott <bpabbott@mac.com>
+## Created: 2010-10-15
+
+function s = untabify (t, tw = 8, db = false)
+
+ if (nargin > 0 && nargin < 4 && (ischar (t) || iscellstr (t)))
+   if (ischar (t))
+     s = replace_tabs (t, tw);
+   else
+     s = cellfun (@(str) replace_tabs (str, tw), t, "uniformoutput", false);
+   endif
+   if (db)
+     s = deblank (s);
+   endif
+ else
+   print_usage ();
+ endif
+
+endfunction
+
+function s = replace_tabs (t, tw)
+ if (ndims (t) == 2)
+   if (isempty (t))
+     s = t;
+   else
+     nr = rows (t);
+     sc = cell (nr, 1);
+     for j = 1:nr
+       n = 1:numel(t(j,:));
+       m = find (t(j,:) == "\t");
+       t(j,m) = " ";
+       for i = 1:numel(m)
+         k = tw * ceil (n(m(i)) / tw);
+         dn = k - n(m(i));
+         n(m(i):end) += dn;
+       endfor
+       sc{j} = blanks (n(end));
+       sc{j}(n) = t(j,:);
+     endfor
+     s = char (sc);
+   endif
+ else
+   error ("untabify: character strings to untabify must have 2 dimensions");
+ endif
+endfunction
+
+%!test
+%! s = untabify ("\thello\t");
+%! assert (isequal (s, horzcat (blanks(8), "hello   ")))
+
+%!test
+%! s = untabify ("\thello\t", 4, true);
+%! assert (isequal (s, horzcat (blanks(4), "hello")))
+
+%!test
+%! s = untabify ("\thello\t", 2, true);
+%! assert (isequal (s, horzcat (blanks(2), "hello")))
+
+%!test
+%! s = untabify ("");
+%! assert (isempty (s))
+
+%!test
+%! s = char (fix (100 + 10*rand (3,3)));
+%! assert (isequal (untabify (s), untabify ({s}){1}))
+