lisp/tabify.el

   1 ;;; tabify.el --- tab conversion commands for Emacs
   2
   3 ;; Maintainer: FSF
   4 ;; Last-Modified: 09 May 1991
   5
   6 ;; Copyright (C) 1985 Free Software Foundation, Inc.
   7
   8 ;; This file is part of GNU Emacs.
   9
  10 ;; GNU Emacs is free software; you can redistribute it and/or modify
  11 ;; it under the terms of the GNU General Public License as published by
  12 ;; the Free Software Foundation; either version 2, or (at your option)
  13 ;; any later version.
  14
  15 ;; GNU Emacs is distributed in the hope that it will be useful,
  16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 ;; GNU General Public License for more details.
  19
  20 ;; You should have received a copy of the GNU General Public License
  21 ;; along with GNU Emacs; see the file COPYING.  If not, write to
  22 ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  23
  24 ;;; Code:
  25
  26 ;;;###autoload
  27 (defun untabify (start end)
  28   "Convert all tabs in region to multiple spaces, preserving columns.
  29 The variable tab-width controls the action."
  30   (interactive "r")
  31   (save-excursion
  32     (save-restriction
  33       (narrow-to-region start end)
  34       (goto-char start)
  35       (while (search-forward "\t" nil t)        ; faster than re-search
  36         (let ((start (point))
  37               (column (current-column))
  38               (indent-tabs-mode nil))
  39           (skip-chars-backward "\t")
  40           (delete-region start (point))
  41           (indent-to column))))))
  42
  43 ;;;###autoload
  44 (defun tabify (start end)
  45   "Convert multiple spaces in region to tabs when possible.
  46 A group of spaces is partially replaced by tabs
  47 when this can be done without changing the column they end at.
  48 The variable tab-width controls the action."
  49   (interactive "r")
  50   (save-excursion
  51     (save-restriction
  52       (narrow-to-region start end)
  53       (goto-char start)
  54       (while (re-search-forward "[ \t][ \t][ \t]*" nil t)
  55         (let ((column (current-column))
  56               (indent-tabs-mode t))
  57           (delete-region (match-beginning 0) (point))
  58           (indent-to column))))))
  59
  60 ;;; tabify.el ends here