Re: Proposal: Forwards-Compatibility Library for Emacs

[Lars Ingebrigtsen]

Richard Stallman <rms@gnu.org> writes:

>   > The idea is to allow developers who don't want to break backwards
>   > compatibility to use newer functionality that wasn't provided in older
>   > versions of Emacs. This version tries to implement as much as possible
>   > from Emacs 24.2 onwards.
>
> Would you please state concretely what this package would do?

The library defines versions of newer functions if Emacs doesn't already
have them.  For instance, Emacs 28 has a new function
'buffer-local-boundp'.  Philip's library would provide a definition of
functions like that for use in ELPA code that's written for newer Emacs
versions, so that they can be used in older Emacs versions without
introducing compatibility shims like `foo-package-buffer-local-boundp'.

This also allows us to put (more) core packages into GNU ELPA without
any code changes.

>   > By its very nature it is an intrusive package, as it defines functions,
>   > macros and advice outside of the "namespace", but I don't see any way
>   > around that if transparent compatibility is to be provided (anything
>   > else would just replicate dash, s, f, ...).
>
> I have a plan to put those names into optional namespaces (using
> symbol renaming) so that the entry points of those packages will
> be visible only from packages that require specific libraries.

Philip shouldn't have mentioned s and dash and the rest -- his proposal
has absolutely nothing to do with those, but it seems like many people
have lashed onto that part, somehow.

-- 
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