Re: [O] Discussion request: 15m tangle time, details follow

[Sebastien Vauban]

Hi Aaron,

Aaron Ecay wrote:
> [...]
> babel needs to fetch 30 properties per source block.  Indeed, this is
> marked “deprecated” in the source, in favor of a system where there is
> only one header arg.  This has been marked deprecated for almost exactly
> a year in the code (Achim’s commit 90b16870 of 2013-06-23), but I don’t
> know of any prominent announcement of the deprecation.

I neither was aware of such a deprecation.

Are you talking of the comment in function
`org-babel-params-from-properties' (in ob-core.el)?

Thought, I can't parse it yet the way you do -- without understanding
much more of that code, as the comments differ in "at point of
definition" vs "at point of call":

     ;; DEPRECATED header arguments specified as separate property at
     ;; point of definition

     ;; header arguments specified with the header-args property at
     ;; point of call

What you're talking about is for specifying header arguments in
a subtree, anyway always at the same point:

> [...] You’d then have to update your file:
>
>   :PROPERTIES:
>   :exports: none
>   :tangle: no
>   :END:
>
> becomes
>
>   :PROPERTIES:
>   :header-args: :exports none :tangle no
>   :END:
>
> The new system is also a bit inferior, in that it doesn’t allow header
> arg inheritance as easily.  So with the one-prop-per-arg system the
> following works as expected:
>
>   * foo
>     :PROPERTIES:
>     :exports: none
>     :END:
>   ** bar
>      :PROPERTIES:
>      :tangle: no
>      :END:
>
>   (src block here)
>
> On the other hand, in the new system there’s no way to specify some
> header args at foo and some at bar; the lowest header-args property
> wins.  (At least as far as I can see)

Maybe the "+" mechanism for concatenating property strings would help
here?

Best regards,
  Seb

-- 
Sebastien Vauban