RE: Emacs rewrite in a maintainable language

[Drew Adams]

> > This way, whenever someone needs fast code, he would use this other
> > dialect instead of writing C, or the slow Elisp (or avoiding the
> > task altogether.)
> 
> If it can leverage what the contributor already knows about Elisp,
> I'm all for it. I wonder what RMS' and Eli's reaction would be.

I'm not for it.  I guess it depends on just how "whenever someone
needs fast code" is interpreted, in practice.

I do not wish to see Emacs core developers start opting for
something like this instead of using Lisp, with the excuse that
they want their given code to be "fast".

That would be an unwelcome blow to Emacs, the extendable,
customizable editor.  Emacs is in Lisp for the sake of its users,
above all.  The only difference today between implementation
language and user language is the C code.  I think of that
(relatively small) bit of code as essentially a necessary evil.

Emacs _is_ a Lisp environment.  This has been the case since
before the existence of Lisp machines.  It is no accident that
the development of Emacs (in various flavors) went hand in hand
with Lisp development.

> compilation into C for some of the functions we have in Emacs
> core

This is backwards from the direction we have been moving with
Stefan and Eli, which is toward moving core stuff from C to
Lisp when possible.

> (that is, reimplementing them as a proof of concept),

OTOH, if it's _only_ to test POC, then I suppose it's hard to
object.  But I would not want to see compiling core Lisp code
to the proposed language be taken seriously.  That would be a
step backward, IMO.

Leave such code in Lisp, please.  And move more core code to
Lisp, when that is feasible.  (As Eli has noted, most of the
C code cannot feasibly be moved to Lisp.)

> that would help sell it.

To whom are you trying to sell it?  What's the point?  Emacs
is too slow?  C is too hard to maintain?

To be clear, if it is a question of using such a language
_only_ for the equivalent of what C is _necessarily_ used for,
it's hard to object.  But if it is just to have "fast" core
code, where that code could be in Lisp instead, then I object,
as one user.