Re: Empty headline titles unsupported: Bug?

[Tim Cross]

David Masterson <dsmasterson92630@outlook.com> writes:

> Nicolas Goaziou <mail@nicolasgoaziou.fr> writes:
>
>> Sebastian Miele <sebastian.miele@gmail.com> writes:
>
>>> Sebastian Miele <sebastian.miele@gmail.com> writes:
>>>>David Masterson <dsmasterson92630@outlook.com> writes:
>>>>> Sebastian Miele <sebastian.miele@gmail.com> writes:
>>>>>> Currently org-syntax.org says that "TITLE can be made of any
>>>>>> character but a new line.  Though, it will match after every other
>>>>>> part have been matched."  This does not reflect the currently
>>>>>> effective behavior that "* :t:" is a headline with title ":t:" and no
>>>>>> tags.
>
>>>>> Can you describe what should happen in a parser grammar (ie. BNF)?  If
>>>>> not, I would tend toward rethinking the structure of the Org file so
>>>>> that it can be described in a grammar.  Having a good grammar for Org
>>>>> files will promote it's acceptance beyond Emacs.
>
>>>> [...]  However, the way I understand the above quote from
>>>> org-syntax.org (which is, I think, in the end preferable) [...]
>
>>> To be clearer: Preferable to the way it currently is implemented.
>>>
>>> In the headline "* :t:", the above quote from org-syntax.org (at least
>>> in my way of reading it) means TAGS ":t:"
>
>> This is your way of reading it, but it's unfortunately not the sole way
>> to look at it. Also, I'm sympathetic to Ihor Radchenko's desire to see
>> consistent code in that area. But being consistent means we favor one
>> interpretation over the other.
>
> Is there anything wrong with that?
>

I don't think the question is whether there is anything wrong, but
rather which interpretation to adopt. Currently, both use cases can be
catered for. However, once you lock in one interpretation, the other use
case is not possible. Which one should we favour? 

My personal preference would be to keep it simple. A value of :t: is a
tag and you cannot have a heading of the format :t:, but that is just my
view.

>> Currently, what Org does in this situation is unimportant, because the
>> behaviour is simply undefined, which is, IMO, tolerable. If we decide to
>> define it, it needs to be documented.
>
> But having undefined behaviors is limiting on the portability of Org
> because people are unwilling to pick it up and attempt to (say) create a
> (partial) Org for other platforms (iPhone, Android, etc.). 

This is very much a secondary consideration. While making it as easy as
possible to parse org files outside of Emacs is not a bad thing, it
should not be a primary driver for how org works. Org is an emacs mode
and I think we need to be careful when considering limiting what you can
do with it based on how easily it can be formally specified for external
tools to use. I think few org users would welcome a change which removed
a feature or required them to modify their workflow just to support the
development of non-emacs tools. 

-- 
Tim Cross