Fix buffer-list rename&refresh after after killing a buffer in ido.
[emacs.git] / lisp / tabify.el
blobc8cf877cb9cfa2806da103ad081c3b3bda0ae754
1 ;;; tabify.el --- tab conversion commands for Emacs
3 ;; Copyright (C) 1985, 1994, 2001, 2002, 2003, 2004,
4 ;; 2005, 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
6 ;; Maintainer: FSF
8 ;; This file is part of GNU Emacs.
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 3 of the License, or
13 ;; (at your option) any later version.
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.
20 ;; You should have received a copy of the GNU General Public License
21 ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
23 ;;; Commentary:
25 ;; Commands to optimize spaces to tabs or expand tabs to spaces in a region
26 ;; (`tabify' and `untabify'). The variable tab-width does the obvious.
28 ;;; Code:
30 ;;;###autoload
31 (defun untabify (start end)
32 "Convert all tabs in region to multiple spaces, preserving columns.
33 Called non-interactively, the region is specified by arguments
34 START and END, rather than by the position of point and mark.
35 The variable `tab-width' controls the spacing of tab stops."
36 (interactive "r")
37 (save-excursion
38 (save-restriction
39 (narrow-to-region (point-min) end)
40 (goto-char start)
41 (while (search-forward "\t" nil t) ; faster than re-search
42 (forward-char -1)
43 (let ((tab-beg (point))
44 (indent-tabs-mode nil)
45 column)
46 (skip-chars-forward "\t")
47 (setq column (current-column))
48 (delete-region tab-beg (point))
49 (indent-to column))))))
51 (defvar tabify-regexp " [ \t]+"
52 "Regexp matching whitespace that tabify should consider.
53 Usually this will be \" [ \\t]+\" to match a space followed by whitespace.
54 \"^\\t* [ \\t]+\" is also useful, for tabifying only initial whitespace.")
56 ;;;###autoload
57 (defun tabify (start end)
58 "Convert multiple spaces in region to tabs when possible.
59 A group of spaces is partially replaced by tabs
60 when this can be done without changing the column they end at.
61 Called non-interactively, the region is specified by arguments
62 START and END, rather than by the position of point and mark.
63 The variable `tab-width' controls the spacing of tab stops."
64 (interactive "r")
65 (save-excursion
66 (save-restriction
67 ;; Include the beginning of the line in the narrowing
68 ;; since otherwise it will throw off current-column.
69 (goto-char start)
70 (beginning-of-line)
71 (narrow-to-region (point) end)
72 (goto-char start)
73 (let ((indent-tabs-mode t))
74 (while (re-search-forward tabify-regexp nil t)
75 ;; The region between (match-beginning 0) and (match-end 0) is just
76 ;; spacing which we want to adjust to use TABs where possible.
77 (let ((end-col (current-column))
78 (beg-col (save-excursion (goto-char (match-beginning 0))
79 (skip-chars-forward "\t")
80 (current-column))))
81 (if (= (/ end-col tab-width) (/ beg-col tab-width))
82 ;; The spacing (after some leading TABs which we wouldn't
83 ;; want to touch anyway) does not straddle a TAB boundary,
84 ;; so it neither contains a TAB, nor will we be able to use
85 ;; a TAB here anyway: there's nothing to do.
86 nil
87 (delete-region (match-beginning 0) (point))
88 (indent-to end-col))))))))
90 (provide 'tabify)
92 ;; arch-tag: c83893b1-e0cc-4e57-8a09-73fd03466416
93 ;;; tabify.el ends here