Re: Proposal: Forwards-Compatibility Library for Emacs

[Philip Kaludercic]

João Távora <joaotavora@gmail.com> writes:

> On Tue, Sep 21, 2021 at 4:02 PM Lars Ingebrigtsen <larsi@gnus.org> wrote:
>
>> The point here is to not to have any separate namespace, so that you can
>> just can put core packages into ELPA without doing any rewrites.
>>
>> What's the concrete risk here?
>
> 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, that is why full compatibility isn't possible, but on the other
hand, these kinds of changes are not that common to begin with. After
all, you don't want to break existing code, with or without a
compatibility library.

-- 
        Philip Kaludercic