RE: Documenting buffer display

[Drew Adams <drew.adams@oracle.com>]

> Attached find a rewrite of the documentation of buffer display
> functions to be applied against the release branch.
> 
> Work in progress.  Proofreading and suggestions welcome.
> 
> Thanks for the attention, martin

Thanks very much for working on this area of the documentation!
This is an area where things have become more complicated and
could use clarification. Working on this really helps.

I only skimmed your patch, but I have at least this comment: I
object to the removal of doc for, and the downplay of support
for, `pop-up-frames' etc. Such variables are very handy; they
should continue to be fully supported and even touted, IMO.

Yes, I am perhaps a lone voice in this regard, but I wanted
to once again voice my disagreement about this, FWIW.

In addition to the wholesale removal of such doc, this, for
instance, is the wrong direction to take, IMHO:

+Many efforts in the design of @code{display-buffer} have been given
+to maintain compatibility with code that uses older options like
+@code{pop-up-windows}, @code{pop-up-frames},
+@code{pop-up-frame-alist}, @code{same-window-buffer-names} and
+@code{same-window-regexps}.  Applications and users should refrain
+from using these options in future code.  Above we already warned
+against customizing @code{pop-up-frame-alist}.  Here we describe how
+to convert the remaining options to use display actions instead.

(I don't object to the "many efforts...to maintain compatibility...".
In fact, I applaud such effort and compatibility. I object to it being
considered only backward compatibility. I object to discouraging
or phasing out such useful constructs. If they didn't exist then
we should want to invent them...)

Being able to simply bind an option such as `pop-up-frames',
to change the behavior of existing code, is very useful.

Richard's arguments why dynamic binding of variables (in _addition_
to lexical binding) is particularly useful for _Emacs_ is relevant here.
It is as relevant today as when it was written, decades ago:

https://www.gnu.org/software/emacs/emacs-paper.html#SEC17

https://www.gnu.org/software/emacs/emacs-paper.html#SEC18

Please keep supporting, and not at all discourage, `pop-up-frames'
and similar.

Thanks for listening, and thanks for the ton of careful work you've
put in for this documentation and to make buffer display more
configurable.