lisp/rot13.el

   1 ;;; rot13.el --- display a buffer in rot13.
   2
   3 ;; Author: Howard Gayle:
   4 ;; Maintainer: FSF
   5 ;; Last-Modified: 16 Mar 1992
   6
   7 ;; Copyright (C) 1988 Free Software Foundation, Inc.
   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 2, or (at your option)
  14 ;; 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; see the file COPYING.  If not, write to
  23 ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  24
  25 ;; Commentary:
  26
  27 ;; Written by Howard Gayle.  See case-table.el for details.
  28
  29 ;; This hack is mainly to show off the char table stuff.
  30
  31 ;;; Code:
  32
  33 (defvar rot13-display-table
  34   (let ((table (make-display-table))
  35         (i 0))
  36     (while (< i 26)
  37       (aset table (+ i ?a) (make-rope (+ (% (+ i 13) 26) ?a)))
  38       (aset table (+ i ?A) (make-rope (+ (% (+ i 13) 26) ?A)))
  39       (setq i (1+ i)))
  40     table)
  41   "Char table for rot 13 display.")
  42
  43 (defun rot13-other-window ()
  44   "Display current buffer in rot 13 in another window."
  45   (interactive)
  46   (let ((w (display-buffer (current-buffer) t)))
  47     (set-window-display-table w rot13-display-table)))
  48
  49 (provide 'rot13)
  50
  51 ;;; rot13.el ends here