Re: Default lexical-binding to t

[Alan Mackenzie]

Hello, Eli.

On Fri, Nov 08, 2024 at 08:58:40 +0200, Eli Zaretskii wrote:
> > Date: Thu, 7 Nov 2024 21:23:38 +0000
> > Cc: joostkremers@fastmail.fm, emacs-devel@gnu.org
> > From: Alan Mackenzie <acm@muc.de>

> > > > But I do wonder whether the massive time and effort its development
> > > > and proliferation have taken up were worth it.

> > > This could be said about almost every major feature in Emacs that
> > > fundamentally changes the internals.  Are the time, energy, and
> > > massive efforts I invested (and am still investing) in bidirectional
> > > editing support worth it?  I don't know; there are days when I think
> > > it was all a terrible waste.  What about all the multiple changes in
> > > the internals that bring us 3.7% speedup in some benchmark?  What
> > > about support for Lisp threads?  What about the addition of positions
> > > to symbols? in how many error-message situations is this really
> > > important?  And XInput2, and touch devices, etc. etc.

> > No, the difference is that most major features are implemented by one
> > person (or a small team) and are complete in themselves.  Lexical
> > binding involved significant effort from lots and lots of contributors,
> > each having to modify "his own" files as lexical binding steadily
> > morphed from being optional to being compulsory.

> That is factually not true.  You seem to compare the contributions to
> lexical binding and to the other features with different scales, or
> maybe you simply misremember.

They are different.  Most features, such as bidi, are self-contained -
they are very useful for some, or many, users, but they don't upset the
fundaments of Emacs.  Lexical binding was different.  Essentially every
..el file in Emacs had to be modified because of it.

[ .... ]

> > I still wonder who made the decision to convert the entire code base
> > [to lexical binding], and when.

> We all did.

When?  And how?

> If you are against this, you are in a tiny minority, and should
> probably stop fighting this war, because it was lost long ago.

I'm not.  I'm against the process, or lack of process, by which it was
introduced.

I don't think there ever was an explicit decision taken - a thread on
emacs-devel, which ended up with something such as:

    "I think we're all agreed that the advantages of lexical binding
    outweigh the disadvantages, and that from now on we'll work towards
    converting the entire Emacs code base."

..  If there had been such an explicit decision process, we might have
ended up with a better result.  I'm thinking here of the discarding of
functions' parameter lists in .elc files, and their replacement by
numbers coding up some of that information.  For example 514 meaning
exactly two parameters.

[ .... ]

> > I can't remember any discussion of the technical merits and demerits of
> > lexical binding taking place on this list.  I've been subscribed for
> > over 20 years.  Maybe I missed it.  It seems strange, that's all.

> If you don't remember such discussions, then you missed them, yes.  We
> had quite a lot of them over the years.

Yes, there have been some, even some initiated by me, over the past few
years.  But none in the context of deciding whether or not to introduce
lexical binding.  [This is what I meant to say in my last paragraph, but
failed.]

-- 
Alan Mackenzie (Nuremberg, Germany).