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From: jimmy@pyrltd.UUCP (Jimmy Aitken)
Newsgroups: comp.emacs
Subject: gnu emacs lisp question
Message-ID: <1211@pyrltd.UUCP>
Date: 18 Jul 89 09:04:28 GMT
Reply-To: jimmy@pyrltd.UUCP (Jimmy Aitken)
Lines: 40


This is my first attempt at a lisp routine for GNU emacs so excuse the
sloppyness/incorrectness.  What I'm trying to do is toggle certain
vlaaues of variables/states in GNU emacs so that they can be changed
via a single keystroke rather than setting the variable manually.  I
wrote the function by looking at the code for other lisp functions in
the lisp directory of GNU.  Things seem to work OK for the readonly
funtion, but for the clt-arrow, wrap, and mode changes the effect of
changing the variable doesn't appear until I redraw the screen.  Can
anybody explain why and, more importantly, how to fix it?  Also if
there are any style improvements I'll gladly accept criticism.

many thanks,

Jimmy
Here's the code:
(defun toggle ()
  "Toggle the values of certain variables."
  (interactive)
  (message
   "toggle: srwct (control^ searchanycase readonly textmode wrap)")
  (let ((char (read-char)))
    (if (char-equal char (string-to-char "c"))
        (set 'ctl-arrow (not ctl-arrow)))
    (if (char-equal char (string-to-char "r"))
        (toggle-read-only))
    (if (char-equal char (string-to-char "s"))
        (setq case-fold-search (not case-fold-search)))
    (if (char-equal char (string-to-char "t"))
        (if (eq major-mode 'fundamental-mode)
            (text-mode)
          (fundamental-mode)))
    (if (char-equal char (string-to-char "w"))
        (setq truncate-lines (not truncate-lines)))
    ))
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