Re: Proposal: Forwards-Compatibility Library for Emacs

[João Távora]

On Tue, Sep 21, 2021 at 6:22 PM Lars Ingebrigtsen <larsi@gnus.org> wrote:
>
> João Távora <joaotavora@gmail.com> writes:
>
> > It was Philip who described as "intrusive", "by its very nature",
> > since it relies on advice and such.  This can be seen as "dirty" in itself.
> > But say that the contract/promise that a given function in Emacs 28 makes
> > is different from the promise that the same function in Emacs 24.2 makes.
> > The new ELPA code doesn't have a problem, but you have potential problem
> > to all the other 24.2 code that expects the "old promise".  Right?
>
> Yes, some compatibility shims may be problematic -- especially if they
> aren't bug-compatible.

There's some recent prior art to this.  cl-lib.el vs cl.el.  It worked
in principle
but making cl.el-expecting things to function just right with the new cl-lib.el
made Stefan sweat a lot, I think.  I'm glad that's mostly over (at
least in SLY).

João