Re: PROPOSAL: Repurpose one key and reserve it for third-party packages

[Jean Louis]

* Gregory Heytings <gregory@heytings.org> [2021-02-13 11:34]:
> 
> > > To me what you propose looks pretty close to using customize to set
> > > a foobar-set-global-binding variable that would be used in a call to
> > > global-set-key.
> > 
> > Yes, that could also be done, the precise code that is generated is an
> > open question
> > 
> 
> But that would be forbidden by the guideline "Don't define 'C-c LETTER' as a
> key in Lisp programs", wouldn't it?

I think not, as that would not be automated global setting by the
package. User have got the control, user decided, not the package.

> (defcustom foobar-global-key "" "Foobar global key in C-c")
> ...
> (if (length foobar-global-key)
>   (global-set-key (kbd (concat "C-c " foobar-global-key)
> 'foobar-foo-command)))

I would rather keep that without C-c and just let user decide on the
prefix key which could be any. By inspecting already bound key, user
could by trial and error in the wizard choose other rater by user
unused key as prefix for the package.

Like this:

1. This program uses key bindings.

2. You will be asked to assign a prefix key for key bindings in this
   package.

3. We recommend that you assign C-c ANY-LETTER as a prefix key, but
   you may as well choose Super in combination with ANY-LETTER or M
   (Alternative) and so on. Please press the key that you think it
   could be prefix to this package's commands.

4. You have pressed C-x ; that is bound to `comment-set-column'. If
   you now accept C-x ; as prefix for package X, that command will not
   be available on that key any more. Are you sure? Yes or no?

   If not sure, we may recommend that you use C-c ; as prefix for this
   package, would that be fine?

   Continue the loop.

5. Thank you. Your prefix has been set on Super key and letter p. You
   may change "s-p" at any time in future to other prefix by invoking
   function M-x key-wizard-of-oz-for-package-X or by customizing the
   variable `package-X-prefix-key'

The function to assign the prefix key for a package could become Emacs
function so that any new package uses that function to assign the
prefix key for the package or to assign some keys for commands that
are not prefix keys. 

> > But even considering that, what do you think that the long-term issue
> > is? Do you think that with time, people will be using more and more
> > packages that need global keys?
> 
> I do not think, I see.  Just have a look at the starter kits, or at the init
> files of those who make them public.  You'll see that there are many
> packages that need global keys.

Let us have some names of packages to look at it.

Jean