-;; Display a buffer in rot13.
+;;; rot13.el --- display a buffer in rot13.
+
;; Copyright (C) 1988 Free Software Foundation, Inc.
+;; Author: Howard Gayle:
+;; 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,
;; 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:
-;; Written by Howard Gayle. See case-table.el for details.
-
+;; The single entry point, `rot13-other-window', performs a Caesar cipher
+;; encrypt/decrypt on the current buffer and displays the result in another
+;; window. Rot13 encryption is sometimes used on USENET as a read-at-your-
+;; own-risk wrapper for material some might consider offensive, such as
+;; ethnic humor.
+;;
+;; Written by Howard Gayle.
;; This hack is mainly to show off the char table stuff.
+;;; Code:
+
(defvar rot13-display-table
(let ((table (make-display-table))
(i 0))
(while (< i 26)
- (aset table (+ i ?a) (make-rope (+ (% (+ i 13) 26) ?a)))
- (aset table (+ i ?A) (make-rope (+ (% (+ i 13) 26) ?A)))
+ (aset table (+ i ?a) (vector (+ (% (+ i 13) 26) ?a)))
+ (aset table (+ i ?A) (vector (+ (% (+ i 13) 26) ?A)))
(setq i (1+ i)))
table)
"Char table for rot 13 display.")
+;;;###autoload
(defun rot13-other-window ()
- "Display current buffer in rot 13 in another window."
+ "Display current buffer in rot 13 in another window.
+To terminate the rot13 display, delete that window."
(interactive)
(let ((w (display-buffer (current-buffer) t)))
(set-window-display-table w rot13-display-table)))
+;;;###autoload
+(defun toggle-rot13-mode ()
+ "Toggle the use of rot 13 encoding for the current window."
+ (interactive)
+ (if (eq (window-display-table (selected-window)) rot13-display-table)
+ (set-window-display-table (selected-window) nil)
+ (if (null (window-display-table (selected-window)))
+ (set-window-display-table (selected-window) rot13-display-table))))
+
(provide 'rot13)
+
+;;; rot13.el ends here