lisp/textmodes/underline.el

   1 ;;; underline.el --- insert/remove underlining (done by overstriking) in Emacs
   2
   3 ;; Copyright (C) 1985, 2001, 2002, 2003, 2004, 2005,
   4 ;;   2006, 2007, 2008 Free Software Foundation, Inc.
   5
   6 ;; Maintainer: FSF
   7 ;; Keywords: wp
   8
   9 ;; This file is part of GNU Emacs.
  10
  11 ;; GNU Emacs is free software: you can redistribute it and/or modify
  12 ;; it under the terms of the GNU General Public License as published by
  13 ;; the Free Software Foundation, either version 3 of the License, or
  14 ;; (at your option) any later version.
  15
  16 ;; GNU Emacs is distributed in the hope that it will be useful,
  17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 ;; GNU General Public License for more details.
  20
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  23
  24 ;;; Commentary:
  25
  26 ;; This package deals with the primitive form of underlining
  27 ;; consisting of prefixing each character with "_\^h".  The entry
  28 ;; point `underline-region' performs such underlining on a region.
  29 ;; The entry point `ununderline-region' removes it.
  30
  31 ;;; Code:
  32
  33 ;;;###autoload
  34 (defun underline-region (start end)
  35   "Underline all nonblank characters in the region.
  36 Works by overstriking underscores.
  37 Called from program, takes two arguments START and END
  38 which specify the range to operate on."
  39   (interactive "*r")
  40   (save-excursion
  41    (let ((end1 (make-marker)))
  42      (move-marker end1 (max start end))
  43      (goto-char (min start end))
  44      (while (< (point) end1)
  45        (or (looking-at "[_\^@- ]")
  46            (insert "_\b"))
  47        (forward-char 1)))))
  48
  49 ;;;###autoload
  50 (defun ununderline-region (start end)
  51   "Remove all underlining (overstruck underscores) in the region.
  52 Called from program, takes two arguments START and END
  53 which specify the range to operate on."
  54   (interactive "*r")
  55   (save-excursion
  56    (let ((end1 (make-marker)))
  57      (move-marker end1 (max start end))
  58      (goto-char (min start end))
  59      (while (re-search-forward "_\b\\|\b_" end1 t)
  60        (delete-char -2)))))
  61
  62 (provide 'underline)
  63
  64 ;; arch-tag: e7b48582-c3ea-4386-987a-87415f3c372a
  65 ;;; underline.el ends here