Re: Inserting a comma as prefix of headlines (in Org code blocks)

[Bastien <bzg@altern.org>]

Hi Nicolas,

Nicolas Goaziou <n.goaziou@gmail.com> writes:

> Ok then another binding. I still think freeing "," key is the best thing
> to do. More on this below.

Users will still be able to use the "," so this will not really fix
the issue.

>> I think "," is good for priorities, and that preventing speed commands
>> in the several blocks is safe and non-intrusive, that's what my patch
>> did. Let me know if you (strongly) think otherwise!
>
> Well, yes, I strongly think otherwise.
>
> Your patch is relying on `org-in-block-p', which is completely broken in
> this situation.
>
> The fact is that any strictly positive number of "*" at column
> 0 followed by a space define a headline, whatever the context is. In
> other words, headlines have precedence over every other construct in Org
> syntax. 
>
> It's not about the parser. Every low level Org command (and most of the
> high level too) assume, and have always assumed, this. For example, try
> to cycle visibility in the following example (or move forward
> heading...):
>
> * H1
>
> ** H11
>
> #+begin_example
> ** H12
> #+end_example
>
> So, we have to make this point clear once and for all. Otherwise, we
> should as well re-implement all functions working on headlines, because
> if we accept that (org-in-block-p '("example")) returns a non-nil value
> in the previous example, they become all wrong.

I got your point, but "broken" is contextual.

The fact that (org-in-block-p '("src")) returns a non-nil value in

#+begin_src org
** H12
#+end_src

is not wrong in the context of checking whether a speed command should
be prevented or not.  It might be wrong in other contexts, but for
this purpose it is not.

That's similar to TAB, which comma-escapes the content of the block
instead of cycling through the folding states, because it knows it is
in a src block.

>   1. "stars + space" at column 0 define a headline. No exception. Most
>      of Org code (reasonably) assumes this, so we should not let users
>      think otherwise.

Yes.  But it is not because the cursor is at the beginning of a
headline that every function should behave the same.  TAB does not,
speed commands do not either.

>   2. Do not rely on `org-in-block-p'. Please use `org-element-at-point'
>      or `org-element-context' instead. These are not broken, and they
>      are fast enough for any interactive use (but let's not use them for
>      fontification yet).

Btw, can you think of cases where it would be nice to have
`org-element-context' check against a wider context than the closest
one?

-- 
 Bastien