(undigestify-rmail-message): Better error messages.

[bpt/emacs.git] / lisp / rot13.el

diff --git a/lisp/rot13.el b/lisp/rot13.el
index 30c1b3d..9c83132 100644 (file)
--- a/lisp/rot13.el
+++ b/lisp/rot13.el
@@ -21,10 +21,15 @@
 ;; along with GNU Emacs; see the file COPYING.  If not, write to
 ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
 
-;; Commentary:
-
-;; Written by Howard Gayle.  See case-table.el for details.
+;;; Commentary:
 
+;; 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:
@@ -33,18 +38,29 @@
   (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