Re: Emacs and Guile (was: GSoC projects related to Emacs)

[Eli Zaretskii <eliz@gnu.org>]

> From: Leo <sdl.web@gmail.com>
> Date: Tue, 03 Apr 2012 11:36:05 +0800
> 
> On 2012-04-10 06:28 +0800, Bastien wrote:
> > ,----[ Guile-Emacs ]
> > | 
> > | Use libguile as the basis for Emacs's Lisp implementation and begin
> > | replacing the Elisp interpreter with Guile
> > | 
> > | http://www.google-melange.com/gsoc/proposal/review/google/gsoc2012/bpt/23002
> > `----
> 
> I am looking forward to this ;)

I don't.

FWIW, my (admittedly short) experience with Guile is that it is not
reliable or stable on anything but GNU/Linux, and even there it has
much to catch up.  It has a lot to gain in terms of portability before
it can be considered seriously as an alternative to ELisp, or even its
sibling on equal rights.

As an example, look at the series of reports from my (eventually
successful) attempt to build Guile natively on MS-Windows.  The series
starts here:

  https://lists.gnu.org/archive/html/bug-guile/2012-01/msg00034.html

Please read the diffs and the analysis I posted, and you will see that
very important core features will simply not exist if some library
function or API are not supported by the underlying environment.  So
much so that some .scm files that are part of Guile itself will simply
fail to compile (and break the entire build of Guile), when one of
these features is missing.  To me, the failure to build in these cases
is a clear sign of a package that is not ready for prime time.  I
think simply nobody tried to build or work with it seriously on any
system except latest versions of GNU/Linux (and a couple of others),
see this thread:

  http://lists.gnu.org/archive/html/guile-user/2011-09/msg00064.html

Or consider Guile's support of non-ASCII characters, which relies on
libiconv with no additional features -- we cannot possibly consider
this complete enough to replace what we have in Emacs now.

And before you consider the above FUD and nothing else: GNU Make
recently added Guile support (available only from the Make CVS
repository for now), and even though Make's needs are much simpler
than Emacs's, you can get the feeling about the problems in this
thread:

  http://lists.gnu.org/archive/html/guile-user/2012-01/msg00130.html

Etc., etc.  I would suggest some serious analysis of Guile as it
stands today by someone who knows much more about it than I do, in
comparison with ELisp and the related Emacs infrastructure, and then
some serious discussions with Guile developers about the gaps, before
we can regard Guile as a contender.  I invite anyone with sufficiently
good knowledge of Emacs internals to look at the Guile equivalents and
see the significant differences, gaps, etc. (or maybe my prejudice and
misunderstandings, who knows?).  If we want to seriously talk about
Guile, let's first invest some effort in understanding what we are
talking about.