RE: completion.el users?

[Drew Adams]

> > 1. Is auto-complete-mode part of Emacs?  I don't think so.  
> > Let's not divert the thread, if not.  The question is whether
> > Emacs already contains a reasonable replacement for
> > completion.el.
> 
> You asked, I answered. Who's diverting what now?

No one has accused anyone of diverting anything.  Please reread what I wrote.

If auto-complete-mode does what completion.el does, and is better at it, then
certainly we could consider deprecating the latter in favor of the former.  But
for that, a-c-m would need to be added to Emacs first, which is a different, or
at least a broader, topic.

As long as it is not part of Emacs and there is no proposal to add it,
considering a-c-m as a replacement would be a diversion, for this thread.

If someone proposes that a-c-m be added, and its author agrees etc., we can
discuss that.  And if it seems likely to be added then that becomes pertinent to
this topic.

FWIW, from the doc and the demo I looked at, and from comments from others here
and there, a-c-m sounds like something that would be great to add to Emacs.

> > 2. Looking at the auto-complete-mode doc and demo, it's not 
> > clear to me that it is comparable to completion.el.  It certainly
> > does many things that completion.el does not do.  (It is also
> > quite large - multiple directories and files.)  But I don't see
> > that a-c-m actually does what completion.el does.  Can
> > you confirm that it does?
> 
> Like I said, the feature is similar, not identical.

Yes, I understood that.  Nothing wrong with that.  The question I raised is
whether it does what completion.el does.  If not, then perhaps the two
complement each other and both could be useful parts of Emacs.

Or perhaps the functionality of completion.el could be added to a-c-m.  I have
no idea.  But a starting point relative to this discussion about possible
deprecation is to know whether a-c-m already does what completion.el does.

> > I understand that you can create a dictionary for a-c-m of 
> > terms you use.  And I understand that a-c-m does lots of useful
> > things wrt completing programming entities that it knows about.
> > And it records the counts and use times of _completions_ that you use.
> 
> Yes.
> 
> > But what about the completion.el use case?  Does a-c-m record
> > ordinary words (as well as programming constructs) that you
> > type and thus consider them future completion candidates?
> > IOW, does simply typing text, or moving the cursor over
> > text, suffice to turn the words typed or traversed into 
> > completion candidates?
> 
> It allows to use "word in buffer" and "words in buffers in the same 
> mode" as sources of completions, so yes, to an extent. Similarly to 
> `dabbrev-expand'.
> 
> > E.g., if you were writing an essay or some documentation, 
> > does hitting a key complete a word that you start typing, based
> > on words you have used previously (including during past sessions)?
> > From the doc I couldn't tell.
> 
> Past sessions? No.

It sounds to me (not knowledgable about a-c-m) like we should:

1. Try to see if a-c-m can/should be added to Emacs (independently of the
current question).

2. If there is no immediate substitute what completions.el does, leave it in
Emacs until there is.

3. See if a-c-m could be enhanced to provide what completion.el offers.  I agree
that it sounds close already, from your comments.