bug#46627: [PATCH] Add new help command 'describe-command'

[Eli Zaretskii]

> Cc: larsi@gnus.org, stefan@marxist.se, rms@gnu.org, 46627@debbugs.gnu.org
> From: Dmitry Gutov <dgutov@yandex.ru>
> Date: Tue, 2 Mar 2021 03:40:02 +0200
> 
> >> All of these (with possible exception of completion.el, which I'm not
> >> familiar with) determine how completions are shown and/or how matching
> >> is performed, but the total set of completions (completion table) is
> >> determined by the command the user invokes.
> > 
> > The completion style does determine the set of candidates, if that's
> > the only aspect you are interested in. 
> 
> Completion style only determines how completions are matched, but not 
> the total set of them. That's defined either by the completion table, or 
> by a completion predicate.

Perhaps I'm missing something, but if, for example, you use the
'initials' style, then "lch" can complete to list-command-history, but
if you don't use 'initials', it will complete to nothing.  So maybe
you are right from the implementation POV, but the list of the
candidates shown to the user is in fact determined by the style.  And
that displayed list is what matters for discovery; that Emacs
internally had some other list is immaterial.

> > I wasn't talking only about describe-command, not even in particular
> > about it.  I was talking about a much more general issue.  If
> > describe-command is the only addition, then I have no problems with
> > that; I only care if that command is the tip of a much larger iceberg.
> 
> I don't think it's going to be.

Then we will be fine.

> Even if we wanted, there are only so many free key bindings anyway. And 
> having more and more commands, bound to different keys, is not actually 
> something that's going to help a new user get oriented quickly.

I agree.