Re: Completions and history

[Ergus]

On Tue, Apr 12, 2022 at 07:20:02PM +0300, Juri Linkov wrote:
> > > > I suppose that this has been discussed before... so is there a reason
> > > > why this has not been implemented? Should I open a feature request or is
> > > > someone already opened?
> > >
> > > Indeed, this has been discussed recently in
> > > https://lists.gnu.org/archive/html/emacs-devel/2021-12/msg00802.html
> > > but no feature request was opened, since C-TAB is already taken by
> > > file-cache-minibuffer-complete.
> >
> > At least could we have documented how to enable this and then let the
> > user set it? Ivy users will find it comfortable in C-r to substitute the
> > Current isearch-backward, other may prefer something else. The default
> > binding may be agreed latter.
>
> One problem is that completions are sorted alphabetically that
> makes no sense for history items which are sorted chronologically.
> So the first thing to do would be to add sorting keys in Completions
> that will allow switching the order between alphabetical and unsorted
> (history items are in chronological order, so unsorted should keep it)
> that will change the value of 'completions-sort'.
A comment about this... completion-at-point-functions accept a list with
a format (START END COLLECTION . PROPS)

The PROPS can be any :completion-extra-properties plus predicate and
exclusive.. maybe the way to do this is to add a property :sort or
similar... Then on the other side we use that property to select the
sorting method... Does it makes sense?

> Another question: should duplicate history items be retained
> in the Completions window when history-delete-duplicates is nil?