[Orgmode] Re: [BABEL] "unset" :var definitions for subtree

[Eric Schulte]

[...]
>
> I agree, the things I was talking about don't end up being simpler in
> terms of usage for this case. My thinking was that variable unsetting
> might be something that would be required fairly rarely, and so it might
> be worth appropriate to support it as part of a more general/powerful
> mechanism tied into Org properties, or even that hook.
>

It does sound like if there were a way to disable inheritance for
certain properties for certain sub-trees of a document, then that would
be ideal -- although I can't imagine how such functionality would be
implemented.  Can we think of an Org-wide syntax for disinheriting
specific properties?

>
> Before we proceed with the variable unsetting, could someone provide a
> motivating example, just to convince ourselves that the extra features
> are justified? (The conclusion of another message was that the torque
> script example was more a motivating example for shebang/preamble
> processing than for variable unsetting.)
>

Certainly.

1. taking Rainer's first example, lets say that you want a variable
   specified for all but one code block in a file (maybe that one code
   block is the source of the value of the variable).  In this case it
   would be much simpler to specify the variable file-wide, and then
   unset the variable for that one code block.

2. say you want the same session for /nearly/ every code block in a
   file.

3. same for :dir, :file, or :shebang...


So, in summary, I am all for a general org-mode wide solution for
disinheriting specific properties, however, if we are unable to find
such a solution then I would lean towards implementing this for Babel
specifically.

Best -- Eric