emacs/lisp/tabify.el
1991-05-09 21:50:55 +00:00

53 lines
1.9 KiB
EmacsLisp

;; Tab conversion commands for Emacs
;; Copyright (C) 1985 Free Software Foundation, Inc.
;; This file is part of GNU Emacs.
;; GNU Emacs 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 1, or (at your option)
;; any later version.
;; GNU Emacs 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 GNU Emacs; see the file COPYING. If not, write to
;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
;;;###autoload
(defun untabify (start end)
"Convert all tabs in region to multiple spaces, preserving columns.
The variable tab-width controls the action."
(interactive "r")
(save-excursion
(save-restriction
(narrow-to-region start end)
(goto-char start)
(while (search-forward "\t" nil t) ; faster than re-search
(let ((start (point))
(column (current-column))
(indent-tabs-mode nil))
(skip-chars-backward "\t")
(delete-region start (point))
(indent-to column))))))
;;;###autoload
(defun tabify (start end)
"Convert multiple spaces in region to tabs when possible.
A group of spaces is partially replaced by tabs
when this can be done without changing the column they end at.
The variable tab-width controls the action."
(interactive "r")
(save-excursion
(save-restriction
(narrow-to-region start end)
(goto-char start)
(while (re-search-forward "[ \t][ \t][ \t]*" nil t)
(let ((column (current-column))
(indent-tabs-mode t))
(delete-region (match-beginning 0) (point))
(indent-to column))))))