Add arch taglines

[bpt/emacs.git] / lisp / tabify.el

diff --git a/lisp/tabify.el b/lisp/tabify.el
index 492bd48..a28f0d6 100644 (file)
--- a/lisp/tabify.el
+++ b/lisp/tabify.el
@@ -1,11 +1,14 @@
-;; Tab conversion commands for Emacs
-;; Copyright (C) 1985 Free Software Foundation, Inc.
+;;; tabify.el --- tab conversion commands for Emacs
+
+;; Copyright (C) 1985, 1994 Free Software Foundation, Inc.
+
+;; Maintainer: FSF
 
 ;; 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)
+;; the Free Software Foundation; either version 2, or (at your option)
 ;; any later version.
 
 ;; GNU Emacs is distributed in the hope that it will be useful,
@@ -14,40 +17,67 @@
 ;; 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.
+;; along with GNU Emacs; see the file COPYING.  If not, write to the
+;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+;; Boston, MA 02111-1307, USA.
+
+;;; Commentary:
+
+;; Commands to optimize spaces to tabs or expand tabs to spaces in a region
+;; (`tabify' and `untabify').  The variable tab-width does the obvious.
 
+;;; Code:
 
 ;;;###autoload
 (defun untabify (start end)
   "Convert all tabs in region to multiple spaces, preserving columns.
-The variable tab-width controls the action."
+Called non-interactively, the region is specified by arguments
+START and END, rather than by the position of point and mark.
+The variable `tab-width' controls the spacing of tab stops."
   (interactive "r")
   (save-excursion
     (save-restriction
-      (narrow-to-region start end)
+      (narrow-to-region (point-min) 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))
+       (forward-char -1)
+       (let ((tab-beg (point))
+             (indent-tabs-mode nil)
+             column)
+         (skip-chars-forward "\t")
+         (setq column (current-column))
+         (delete-region tab-beg (point))
          (indent-to column))))))
 
+(defvar tabify-regexp "[ \t][ \t]+"
+  "Regexp matching whitespace that tabify should consider.
+Usually this will be \"[ \\t][ \\t]+\" to match two or more spaces or tabs.
+\"^[ \\t]+\" is also useful, for tabifying only initial whitespace.")
+
 ;;;###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."
+Called non-interactively, the region is specified by arguments
+START and END, rather than by the position of point and mark.
+The variable `tab-width' controls the spacing of tab stops."
   (interactive "r")
   (save-excursion
     (save-restriction
-      (narrow-to-region start end)
+      ;; Include the beginning of the line in the narrowing
+      ;; since otherwise it will throw off current-column.
+      (goto-char start)
+      (beginning-of-line)
+      (narrow-to-region (point) end)
       (goto-char start)
-      (while (re-search-forward "[ \t][ \t][ \t]*" nil t)
+      (while (re-search-forward tabify-regexp nil t)
        (let ((column (current-column))
              (indent-tabs-mode t))
          (delete-region (match-beginning 0) (point))
          (indent-to column))))))
+
+(provide 'tabify)
+
+;;; arch-tag: c83893b1-e0cc-4e57-8a09-73fd03466416
+;;; tabify.el ends here