Re: Is Elisp really that slow?

[Óscar Fuentes]

Eli Zaretskii <eliz@gnu.org> writes:

>> Emacs is amazing, but as far as productivity goes, at least as a
>> programmer's editor for popular languages, it is far behind current
>> contenders.
>
> You've changed the subject, yes?  This was never about productivity.
>
> I agree that our situation with IDE features is quite bleak, but
> that's entirely unrelated to the issues discussed in this thread, and
> its reasons IMO have nothing to do with either ELisp speed or
> flexibility of Emacs in general.

It has a lot to do. Analyzing source code is cpu-intensive, because it
is algorithmically complex and lots of data needs to be processed.

The ill-fated Semantic package, despite all the effort invested on
implementing speed-ups, suffered badly from this and AFAIK it was one of
the main causes of its failure.

Even if you defer the actual analysis to an external tool (which is the
sane thing to do, BTW) the amount of data to be processed on the Emacs
end can be quite large, more than enough to introduce perceptible delays
that spoil the experience.