Re: RFC: Adding BBDB to Emacs core

[Paul Eggert]

On 04/24/2018 03:31 PM, Stefan Monnier wrote:
> adding runtime conditional logic has
> been standard procedure "for ever" and comes with all kinds of
> advantages,

It's a tradeoff, though, as the runtime logic makes the code harder to 
maintain and (particularly) to test, and at some point it becomes more 
trouble than it's worth. This is why Gnus dropped support for Emacs 22 a 
couple of years ago. Even if ELPA packages should work on current and 
previous Emacs versions, today I would think that they shouldn't have to 
worry about porting to Emacs 23 or earlier, and that a package's 
maintainer can determine whether the cutoff is 22, 23, or even 24.