bug#66554: [PATCH] Add the public API of Compat to the core

[Eli Zaretskii <eliz@gnu.org>]

> From: Philip Kaludercic <philipk@posteo.net>
> Cc: Daniel Mendler <mail@daniel-mendler.de>,  66554@debbugs.gnu.org,
>   monnier@iro.umontreal.ca,  stefankangas@gmail.com
> Date: Fri, 19 Jan 2024 16:44:06 +0000
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> >> Compat allows packages to use APIs which are newer than the Emacs they
> >> depend on. A package depending on ((emacs "27.1") (compat "29.1"))
> >> relies on Emacs 27.1 as base line, but can use some APIs from 29.1,
> >> specifically the ones provided by Compat. Is there a better and more
> >> specific term for this than "forward compatibility"?
> >
> > How about
> >
> >   Compat allows packages written for newer Emacs version to still work
> >   with older Emacs versions.
> 
> I think the danger here is that Compat cannot provide full compatibility
> support (some features either too complex to maintain, too slow to
> reproduce or requiring changes in the core), so the way you phrase it
> sounds like more than is being delivered.

I fail to see how what I wrote is different from the text quoted above
that.  If my text promises more than is being delivered, so is the
original text.