Re: C and Emacs Lisp code parts

[Eli Zaretskii <eliz@gnu.org>]

> From: Fabrice Popineau <fabrice.popineau@gmail.com>
> Date: Sat, 2 Jul 2016 16:41:05 +0000 (UTC)
> 
> Eli Zaretskii <eliz <at> gnu.org> writes:
> 
> > As for font-lock, its features are based on regular expression and
> > syntax tables, both of which are implemented in C as well.
> 
> The fact that regexp are implemented in C is not a guarantee of 
> the best speed.
> Some years ago, when the Common Lisp CL-PPCRE library appeared, 
> it was benchmarked 5-20 times faster than C regexp libraries, because
> the automaton was compiled directly to machine code, whereas the C
> counterpart had to do lookups into the table that describes the
> automaton.

Andreas was proposing to push parts of Emacs to C, so the fact that
the C implementation can be improved is not related to the argument.

> I am no specialist of the the current variants of regexp libraries
> but some of them seem to make use of jit compiler.
> (See http://sljit.sourceforge.net/regex_perf.html for example)
> So isnt't there some response time to gain around regexps?

Maybe there is, but that's a separate issue.  Of course, volunteers
are welcome to come up with more efficient implementations.