RE: [External] : Continue cycling from a particular element in collection

[Heime]

------- Original Message -------
On Wednesday, August 23rd, 2023 at 9:11 AM, Heime <heimeborgia@protonmail.com> 
wrote:


> ------- Original Message -------
> On Wednesday, August 23rd, 2023 at 9:04 AM, Drew Adams drew.adams@oracle.com 
> wrote:
> 
> 
> 
> > > > > I am using 'completing-read' with INITIAL-INPUT to prefill the
> > > > > minibuffer
> > > > > with the first entry "alpha". Hew can I then start at index k from
> > > > > collection
> > > > > as the next entry.
> > > > 
> > > > There is NO "next entry". INITIAL-INPUT is simply a string that gets
> > > > inserted in the minibuffer. It need not correspond to any candidate
> > > > provided by argument COLLECTION, meaning that it need not correspond to
> > > > any completion.
> > > > 
> > > > `completing-read' can be LAX, meaning that, if REQUIRE-MATCH is nil or
> > > > absent then it accepts any text you input - it need not be a completion
> > > > candidate.
> > > 
> > > Ok, but can I ask completing-read to start from
> > > a different point in collection, rather than
> > > from the beginning ?
> > 
> > Dunno. I'm no expert on vanilla Emacs cycling,
> > and I'm not sure what kind of cycling ("next entry")
> > you have in mind.
> 
> 
> By 'Next Entry' I mean what shows up after INITIAL-INPUT
> is shown after pressing <down>.
> 
> > If you're using argument DEFAULTS to provide a list
> > of "entries" then you can of course sort it (or
> > truncate it) however you like, to affect the "future
> > history".
> > 
> > If you're using a HISTORY variable and cycling the
> > (past/real) history then I suppose you could sort
> > (or truncate) its value.
> > 
> > But entries in neither DEFAULTS nor HISTORY need be
> > elements of COLLECTION.
> > 
> > If you meant the "future history" elements that are
> > provided by the misfeature of automatically adding
> > everything in COLLECTION to that pseudo-history,
> > then no, AFAIK there's no way to filter, sort, or
> > truncate the elements from COLLECTION that get added.
> > 
> > But maybe there will be now, since I think they're
> > considering adding some option that may help here -
> > dunno.
> > 
> > Maybe someone else will have a useful suggestion.

It is a deficiency on the part of completing-read that makes
INITIAL-INPUT unaware of COLLECTION and of REQUIRE-MATCH.