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

[Eli Zaretskii <eliz@gnu.org>]

> Cc: larsi@gnus.org, stefan@marxist.se, rms@gnu.org, 46627@debbugs.gnu.org
> From: Dmitry Gutov <dgutov@yandex.ru>
> Date: Sun, 28 Feb 2021 23:40:06 +0200
> 
> On 28.02.2021 19:27, Eli Zaretskii wrote:
> 
> >> Do you have in mind some particular "completion alternative we have
> >> already" for 'describe-command'?
> > 
> > icomplete.el, completion.el, pcomplete.el, and the non-default styles
> > in completion-styles-alist come to mind.
> 
> 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.  And the way the candidates are
presented is an important part of how easy and user-friendly discovery
is.

> So they don't include anything that looks like a replacement for 
> 'describe-command'.

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.

> > This loses the context.  Minor improvements were not the issue I
> > raised, the issue was the perceived attempt to build a significant
> > discovery framework based on completion.
> 
> "Significant discovery framework" is something very ill-defined. From 
> where I'm standing, function and variable discovery based on completion 
> is already in Emacs, and we sometimes provide minor fixes and 
> improvement for it (such as this command).

Then we are in fact in violent agreement.

> Sometimes we do request major changes that would help it as well...

That's the issue at hand.  I don't think we need or should entertain
major changes in that area.

> > I have nothing against providing infrastructure for more sophisticated
> > completion, I was talking only about adding new commands which aim to
> > provide discovery based on completion,
> 
> But which otherwise duplicate existing commands?

Duplicate functionality, not commands.

> > or extend existing
> > completion-related commands with the goal of providing discovery
> > through them.
> 
> Do you mean like extensions of the completion-at-point interface with 
> that aim? I'm curious about possibilities, but so far we haven't really 
> discussed them here.

I don't know what I mean, I will know when actual proposals are
brought up.