lisp/tabify.el

   1 ;;; tabify.el --- tab conversion commands for Emacs
   2
   3 ;; Copyright (C) 1985 Free Software Foundation, Inc.
   4
   5 ;; Maintainer: FSF
   6
   7 ;; This file is part of GNU Emacs.
   8
   9 ;; GNU Emacs is free software; you can redistribute it and/or modify
  10 ;; it under the terms of the GNU General Public License as published by
  11 ;; the Free Software Foundation; either version 2, or (at your option)
  12 ;; any later version.
  13
  14 ;; GNU Emacs is distributed in the hope that it will be useful,
  15 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 ;; GNU General Public License for more details.
  18
  19 ;; You should have received a copy of the GNU General Public License
  20 ;; along with GNU Emacs; see the file COPYING.  If not, write to
  21 ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  22
  23 ;;; Code:
  24
  25 ;;;###autoload
  26 (defun untabify (start end)
  27   "Convert all tabs in region to multiple spaces, preserving columns.
  28 Called non-interactively, the region is specified by arguments
  29 START and END, rather than by the position of point and mark.
  30 The variable `tab-width' controls the spacing of tab stops."
  31   (interactive "r")
  32   (save-excursion
  33     (save-restriction
  34       (narrow-to-region start end)
  35       (goto-char start)
  36       (while (search-forward "\t" nil t)        ; faster than re-search
  37         (let ((start (point))
  38               (column (current-column))
  39               (indent-tabs-mode nil))
  40           (skip-chars-backward "\t")
  41           (delete-region start (point))
  42           (indent-to column))))))
  43
  44 ;;;###autoload
  45 (defun tabify (start end)
  46   "Convert multiple spaces in region to tabs when possible.
  47 A group of spaces is partially replaced by tabs
  48 when this can be done without changing the column they end at.
  49 Called non-interactively, the region is specified by arguments
  50 START and END, rather than by the position of point and mark.
  51 The variable `tab-width' controls the spacing of tab stops."
  52   (interactive "r")
  53   (save-excursion
  54     (save-restriction
  55       (narrow-to-region start end)
  56       (goto-char start)
  57       (while (re-search-forward "[ \t][ \t][ \t]*" nil t)
  58         (let ((column (current-column))
  59               (indent-tabs-mode t))
  60           (delete-region (match-beginning 0) (point))
  61           (indent-to column))))))
  62
  63 ;;; tabify.el ends here