undoing define-key

undoing define-key

[jpkotta]

How can I unbind a key in a keymap such that it acts like it was never defined?  The docs make it sound like binding to nil, e.g. (define-key map (kbd "<key>") nil), will do what I want, but it doesn't.

Example (works with emacs -q):

(define-minor-mode foo-mode
  :global t
  :keymap (let ((map (make-sparse-keymap)))
            (define-key map (kbd "M-j") 'left-char)
            (define-key map (kbd "M-k") 'next-line)
            (define-key map (kbd "M-l") 'right-char)
            (define-key map (kbd "M-i") 'previous-line)
            map)
  )
(foo-mode 1)

;; Now M-[ijkl] act like the arrow keys
;; I can do an isearch and they will exit the search just like the arrows

(define-key isearch-mode-map (kbd "M-j") nil)

;; Now M-j does not exit isearch, and it behaves like whatever it was bound to outside of foo-mode.  M-j still does left-char outside of isearch-mode.

Re: undoing define-key

[Stefan Monnier]

> ;; Now M-[ijkl] act like the arrow keys
> ;; I can do an isearch and they will exit the search just like the arrows

> (define-key isearch-mode-map (kbd "M-j") nil)

> ;; Now M-j does not exit isearch, and it behaves like whatever it was
> ;; bound to outside of foo-mode.  M-j still does left-char outside of
> ;; isearch-mode.

And what behavior would you want instead?


        Stefan

Re: undoing define-key

[jpkotta]

On Tuesday, December 18, 2012 6:45:49 PM UTC-6, Stefan Monnier wrote:
> > ;; Now M-[ijkl] act like the arrow keys
> 
> > ;; I can do an isearch and they will exit the search just like the arrows
> 
> 
> 
> > (define-key isearch-mode-map (kbd "M-j") nil)
> 
> 
> 
> > ;; Now M-j does not exit isearch, and it behaves like whatever it was
> 
> > ;; bound to outside of foo-mode.  M-j still does left-char outside of
> 
> > ;; isearch-mode.
> 
> 
> 
> And what behavior would you want instead?
> 
> 
> 
> 
> 
>         Stefan

I wanted to reclaim some keys that were set in isearch-mode-map, and I wanted to do it by making sure they were undefined, so that another keymap would override them.  To be clear, these keys were bound by a 3rd party library, not by default.

It appears to be something special in isearch-mode.  I thought M-[ijkl] were unbound, but they're actually bound to isearch-other-meta-char.  If I bind to that, then everything works as intended.