Re: A simple implementation of context-sensitive keys

[Tassilo Horn <tassilo@member.fsf.org>]

"Lennart Borgman" <lennart.borgman@gmail.com> writes:

Hi Lennart,

>> Sorry, no time to write the code now.  What I mean is that in
>>
>>  (info "(elisp)Searching Keymaps")
>>
>> there's the pseudocode how emacs finds the command for a key.  Now
>> you can surrogate "FIND-IN" with lookup-key and see if the key is
>> bound in the map.  In that code you know the map or at least the
>> mode, cause you either have the variable directly (like
>> overriding-local-map) or you walk an alist of the form ((mode-name
>> . keymap)...) in the case of FIND-IN-ANY.
>
> It would be good if that where true, but it is not. You have to take a
> closer look to understand how this works. I think a good start might
> be the code I sent before.

Here's a q&d implementation of what I thought should do the trick.  It
works for me, although only very briefly tested.

--8<---------------cut here---------------start------------->8---
(defun find-key-commands (key)
  (let (list)
    (when overriding-terminal-local-map
      (let ((c (lookup-key overriding-terminal-local-map key))) 
        (when (and c
                   (not (numberp c)))
          (add-to-list 'list (cons 'overriding-terminal-local-map c) t))))
    (when overriding-local-map
      (let ((c (lookup-key overriding-local-map key))) 
        (when (and c
                   (not (numberp c)))
          (add-to-list 'list (cons 'overriding-local-map c) t))))
    (let ((prop-map (get-char-property (point) 'keymap)))
      (when prop-map
        (let ((c (lookup-key prop-map key))) 
          (when (and c
                     (not (numberp c)))
            (add-to-list 'list (cons 'char-property-keymap c) t)))))
    (dolist (alist '(emulation-mode-map-alists
                     minor-mode-overriding-map-alist
                     minor-mode-map-alist))
      (dolist (x (symbol-value alist))
        (let ((mapname (car x))
              (map (cdr x)))
          (when map
            (let ((c (lookup-key map key))) 
              (when (and c
                         (not (numberp c)))
                (add-to-list 'list (cons mapname c) t)))))))
    (when (get-text-property (point) 'local-map)
      (let ((prop-map (get-char-property (point) 'local-map)))
        (when prop-map
          (let ((c (lookup-key prop-map key))) 
            (when (and c
                       (not (numberp c)))
              (add-to-list 'list (cons 'char-property-local-map c) t))))))
    (when (current-local-map)
      (let ((c (lookup-key (current-local-map) key))) 
        (when (and c
                   (not (numberp c)))
          (add-to-list 'list (cons 'current-local-map c) t))))
    (let ((c (lookup-key (current-global-map) key))) 
      (when (and c
                 (not (numberp c)))
        (add-to-list 'list (cons 'current-global-map c) t)))
    list))

(find-key-commands (kbd "M-1"))
;; ==> ((window-number-mode lambda nil (interactive) (window-number-select 1)) (current-global-map . digit-argument))
(find-key-commands (kbd "C-f"))
;; ==> ((paredit-mode . paredit-forward) (current-global-map . forward-char))
--8<---------------cut here---------------end--------------->8---

Bye,
Tassilo