Re: Adding transient to Emacs core

[Madhu <enometh@meer.net>]

*  Stefan Monnier <monnier@iro.umontreal.ca> <jwvwnspos54.fsf-monnier+emacs@gnu.org>
Wrote on Mon, 26 Apr 2021 13:52:49 -0400

>> If the package does not support use display-buffer according to the
>> design of display-buffer, I maintain it will have a negative impact if
>> adopted in the core and one is constrained to use it (instead of
>> keeping it optional)

> In my experience, among the packages that have to display something
> (as opposed to your usual major-mode which only provides commands to
> navigate and edit text), very few correctly deal with all possible
> `display-buffer-alist` customizations.  The vast majority assumes a
> single-frame setup and break in random way in less conventional
> situations.
>
> So if transient.el misbehaves in some of those cases, it's in pretty
> good company.

And I have the option of not being forced to use those packages when
dealing with emacs.

> In the transient.el API the only thing that could inherently cause
> problem, AFAICT is the fact that it relies on being able to
> display a "sizeable" amount of information to the user, but it's hard to

No this is pretty fundamental. The designer of the transient prompt
can make the prompt big enough to trigger the situations where it
fails.

> imagine a comparable feature that doesn't make similar assumptions, and
> it's hard to imagine a situation where there's really no way to make
> it work.
>
> So any problem it might suffer should be a mere "implementation issue"
> that can be fixed without impacting the packages which rely on it.

Except when they can't because of funamental incompatible assumptions.

(Note I am responding at the same level of generality as your post)

If a core package which worked fine is now modified to use a package
which you introduce and the new package and cannot be used in certain
circumstances (that the developer of the new package has not or cannot
consider) I maintain that the new package destroys existing value -
and if that is the explict intent I hope it is made explicit.