Re: Shrinking the C core

[Ihor Radchenko <yantar92@posteo.net>]

Emanuel Berg <incal@dataswamp.org> writes:

> Please stop pushing for the disallowance of topics related to
> SBCL and Emacs. It is a non-starter.

Well. The main problem with "let's rewrite Emacs using X language" is
that it has been discussed and even attempted (for example:
https://github.com/remacs/remacs, https://github.com/emacs-ng/emacs-ng)
many times. Without success. So, I can see how raising the same topic
yet again does not look productive.

Yet, I do agree that there is no reason to _forbid_ such discussions.
But please clearly mark them under appropriate email subject, so that
people who do not want to follow them could filter out the subject in
their email client and not be bothered.

> Also, please stop pushing for the disencouragement of using
> the GNU Emacs Elisp features provided by cl-lib.
> Also a non-starter.

There is actually reasoning behind discouragement of using cl-lib in
_Emacs source code_. In particular, things like `cl-loop' that
constitute a mini-language of its own (or `pcase' for what its worth).

When such "mini-languages" are used too much, without a clear need,
people not familiar with CL conventions will have harder time to read
the Emacs source code - increased entry barrier for contribution.

Also, it is up to Emacs maintainers to decide on the preferred style
inside Emacs sources.

> One thing that can be discussed is how to get parallelism into
> Emacs, to make use of modern CPU multicore architectures.
>
> Emacs is a single-thread Lisp machine written in C, so can't
> we have a multi-thread Lisp machine, using the same language?
> And not by rewriting the whole thing, rather extending it to
> allow for multithreading?
>
> Didn't anyone try to do that already BTW? It feels like
> a pretty basic idea and multicore CPUs have been around for
> a while.

It is not as easy as you may think. Naive attempts will fail:
https://www.youtube.com/watch?v=7H1Pe9HkJ7I

You can see the gory details in
https://yhetil.org/emacs-devel/871qhnr4ty.fsf@localhost
I'd appreciate if we move the discussion about parallelism there to have
a single place with all the caveats detailed and discussed instead of
scattering things all over emacs-devel.

-- 
Ihor Radchenko // yantar92,
Org mode contributor,
Learn more about Org mode at <https://orgmode.org/>.
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