Re: Most of Elisp lacks lexical-binding: t

[Phil Sainty <psainty@orcon.net.nz>]

On 2019-02-05 16:31, Eli Zaretskii wrote:
> I don't see how we could make this the default before we complete
> converting all the Lisp files to lexical binding (or, unlikely, decide
> that some of them need to use dynamic binding).  It would mean risking
> a lot of breakage.

And that's not just for Emacs core -- there is a massive quantity of
elisp in the ecosystem at large which was not written for lexical
binding, and still works absolutely fine in current versions of Emacs.
Such libraries might well no longer have a maintainer (but at present
not be in any need of one).

Releasing a "lexical-binding by default" version of Emacs would surely
create a substantial risk of many user's configs failing on them in a
variety of ways when they upgrade, and suddenly needing a lot of
effort to get working (which for some users will be outside of their
skill set).

The risk seems rather high to me.  I'm not sure the reward would be
worth it?  (When the reward would seem to be nothing more than library
authors being able to omit -*- lexical-binding: t; -*- which, even if
it looks untidy, isn't exactly an onerous requirement).


-Phil