Re: [O] GSoC 2012 -- Elisp backend for Ragel

[Nicolas Goaziou]

Hello,

Aurélien Aptel <address@hidden> writes:

> On Sun, Mar 25, 2012 at 6:17 AM, Rustom Mody <address@hidden> wrote:
>> FYI, there is already an elisp Org parser being worked on in development
>> branch of Org mode. It isn't finished yet, but still advanced enough so
>> a generic exporter could be built upon it.
>
>> Is there any interest in ignoring it and restart all the work from
>> scratch?
>>
>> Yes I agree, no point redoing work unnecessarily.  Maybe the optimal
>> solution would be for Aurélien to work with Nicolas and Adrian to minimize
>> useless rework?
>
> Regardless of the org-mode parser, I think I should work on the elisp
> backend for ragel which is something that can benefit any elisp
> project.

Certainly.

> As for the new org-mode parser, I could not find it on the repo. Could
> you point me to the relevant files?

See org-element.el in contrib/ directory.  You need development version.

> Is it still hand written? 

Yes.

> If so, I think it's ultimately a bad idea and it should be rewritten
> using ragel.

It may be. But it allows for flexibility. Org's syntax is evolving, and
I consider org-element.el as a parser, but also as a guidance in that
process. Since there is no formal description for Org syntax yet, an
org-element.el is more useful than a full-blown parser generator for
now.

I don't know ragel (save for a short excursion in its website), but I'm
pretty sure that even if it generates elisp code without dependency, any
evolution to Org syntax will require to use it again. At that time, it
may be difficult to find someone able and willing to undertake that
updating task in a reasonable delay (since we're talking about a core
feature). On the other hand, there are quite a few elisp hackers in
Emacs's world.

Now, if ragel can improve org-element.el while preserving its
flexibility (and a compatible output, since I assume you won't also
rewrite the generic export engine), I'm all ears.


Regards,

-- 
Nicolas Goaziou