Re: master f225011: ibuffer-do-isearch: don't depend on `cl-values-list' (bug#38430)

[Stefan Monnier <monnier@iro.umontreal.ca>]

>> This is "broken" in the sense that it makes assumptions about how the
>> "multiple values" are implemented.
> Yes, though we've had that implementation for decades and we're not likely
> going to add true multiple values to elisp.

I must admit I'm biased: I find c-lib's multiple-value support to be
completely worthless.  I don't know anything you can do with that you
can't do just as easily without it.  IOW it only makes sense as
a "compatibility with Common-Lisp", yet it doesn't provide the right
semantics either so it doesn't work for that either.

I regret not having noticed it back in Emacs-24 time when I could have
marked those functions as obsolete (or even kept them in cl.el but not
in cl-lib.el).

>> We do know that `ibuffer-split-list` returns a list, so there's no point
>> going through CL's multiple-values simulation.  We should instead treat
>> it as a list and extract the elements with `pcase-let`
>> (or `cl-destructuring-bind`).
> I tried to do a minimal fix so close to branching for 27, but I can do that
> if you want.

I consider the patch you showed as broken (regardless of whether it
does work in practice, obviously).  Require cl-lib is another way to fix
this, if you want a less intrusive patch.  But we're still "before
branching", so I wouldn't worry about intrusiveness yet.


        Stefan