lisp/rot13.el

   1 ;; Display a buffer in rot13.
   2 ;; Copyright (C) 1988 Free Software Foundation, Inc.
   3
   4 ;; This file is part of GNU Emacs.
   5
   6 ;; GNU Emacs is free software; you can redistribute it and/or modify
   7 ;; it under the terms of the GNU General Public License as published by
   8 ;; the Free Software Foundation; either version 1, or (at your option)
   9 ;; any later version.
  10
  11 ;; GNU Emacs is distributed in the hope that it will be useful,
  12 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 ;; GNU General Public License for more details.
  15
  16 ;; You should have received a copy of the GNU General Public License
  17 ;; along with GNU Emacs; see the file COPYING.  If not, write to
  18 ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  19
  20
  21 ;; Written by Howard Gayle.  See case-table.el for details.
  22
  23 ;; This hack is mainly to show off the char table stuff.
  24
  25 (defvar rot13-display-table
  26   (let ((table (make-display-table))
  27         (i 0))
  28     (while (< i 26)
  29       (aset table (+ i ?a) (make-rope (+ (% (+ i 13) 26) ?a)))
  30       (aset table (+ i ?A) (make-rope (+ (% (+ i 13) 26) ?A)))
  31       (setq i (1+ i)))
  32     table)
  33   "Char table for rot 13 display.")
  34
  35 (defun rot13-other-window ()
  36   "Display current buffer in rot 13 in another window."
  37   (interactive)
  38   (let ((w (display-buffer (current-buffer) t)))
  39     (set-window-display-table w rot13-display-table)))
  40
  41 (provide 'rot13)