Re: Bug: org-element-at-point on headline does not contain :parent property [9.3 (release_9.3 @ /home/yantar92/.emacs.d/straight/build/org/)]

[Nicolas Goaziou <mail@nicolasgoaziou.fr>]

Ihor Radchenko <yantar92@gmail.com> writes:

> Thanks for the clarification. I was not sure if it is intended.
> I was mislead about this 2 times because of docstring, though it is
> clear from the source code.

I fixed the docstring. Thank you.

>> Luckily, headlines are exactly where you do _not_ need Element library.
>> `org-back-to-heading' and `org-up-heading-safe' will always be faster,
>> and as accurate. I.e., the code operating on headlines is usually
>> distinct from the code handling other elements.
>
> Well. `org-back-to-heading` + `org-up-heading-safe` take more than 15% of
> my agenda generation time (I have really huge number of headings +
> multiple custom skip functions). I was hoping to use cache for speed
> up. 

Cache will not help you here. `org-up-heading-safe' and
`org-back-to-heading' are faster than `org-element-at-point' + cache.

Moreover, custom skip functions are a pain. They prevent any form of
caching during agenda creation. IMO, Agenda (or its re-implementation)
should do without them.

>> You can parse the full document and get all the :parent properties
>> filled. That's not the job for `org-element-at-point'.
>
> I once tried to do exactly this, but I did not manage to figure out how
> to obtain element at point from full parse tree (from inside an agenda
> skip function). Is it possible?

It is possible but not implemented.

>> Note that `org-element-cache' was disabled a while ago because it could
>> introduce freezes. I think this is related to how this part handles
>> `before-change-functions' and `after-change-functions'. Anyway, YMMV.
>
> I see... I don't know how useful the cache is except my idea about
> using cache to speed up agenda. But I was stuck with the :parent
> property issue and did not play much further since that time.

I once started to implement Agenda-specific caching, but stopped as it
would have entailed rewriting much of the Agenda code. It would have
been a pain. Even switching "org-agenda.el" to lexical binding is
difficult (and isn't done yet).

Some re-implementation of Agenda (e.g., org-super-agenda + org-ql) may
be better wrt caching.