Re: Limit what M-x TAB lists?

[Lars Ingebrigtsen <larsi@gnus.org>]

Óscar Fuentes <ofv@wanadoo.es> writes:

> Instead of a predicate for every function, the usual Emacs idiom of "if
> it is a symbol, filter by mode, if it is a function, it must be a
> predicate returning non-nil if the command is applicable blah blah...".
> I'll bet that 99% of the commands fall in the "symbol" case, which is
> fast.

Yup.  But perhaps the symbols we want to use here are really mode names?
And mode names are unfortunately also functions...  Hm...

> I'm definitely interested on this idea. It is annoying (as in "Emacs
> looks stupid and counterproductive") to always see useless candidates on
> M-x. If you put the underlying machinery in place, I volunteer for the
> command hunt.

Great!

> It would be nice if the annotations were backwards compatible, so they
> could be added to external packages without making them incompatible
> with past Emacs releases.

Well, if we go with new variations on `interactive', then external
packages could just do something like

(unless (fboundp 'command)
  (defmacro command (&rest args)
    `(interactive ,@(cdr args))))

and then

(defun vc-dir-mark ()
  (command 'vc-dir-mode "p")
  ...)

(defun quit-window ()
  (command (lambda () (..stuff..)) "p")
  ...)
  
Or something.  Would that work, or is `interactive' interpreted even
more specially?  (I.e., before macro expansion...)  Let's see...

(defun foo (arg)
  (command 'bar "p")
  (message "%s" arg))

Yup, seems to work.

-- 
(domestic pets only, the antidote for overdose, milk.)
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