Re: [PATCH] lisp/ob-screen.el: Support ~:var~ header args for babel blocks

[Ihor Radchenko]

Ken Mankoff <mankoff@gmail.com> writes:

>> To archive this, you can define a full
>> org-babel-variable-assignments:screen function that does what I
>> described.
>
> You're pushing my lisp skills here. Which is fine, but I might need some help.
>
> In ob-shell I see
>
> (defcustom org-babel-shell-names
>   '("sh" "bash" "zsh" "fish" "csh" "ash" "dash" "ksh" "mksh" "posh")
>
> Should I create a function that, using case statement or something similar, 
> checks for each of these and calls that flavor? I think I could do that.

Not each of these. AFAIU, :cmd header property in ob-screen defines
which shell to use. Knowing shell name, you can deduce the function name
to be used for variable assignments. See how it is done in
`org-babel-expand-src-block'.

> But if I also see org-babel-shell-initialize in ob-shell that looks like it 
> creates defaliases for each of these to (org-babel-execute:shell) and 
> #'org-babel-variable-assignments:shell.

The convention is for every possible #+begin_src lang to have
org-babel-variable-assignments:LANG.
ob-shell just tries to avoid unnecessary code duplication and instead of
writing identical org-babel-variable-assignments:sh
org-babel-variable-assignments:bash, org-babel-variables-assignents:zsh,
..., it generates them using a macro.

> I'm not sure how that is very different from what I've done. I'm not sure 
> what to do here, nor how to do what you suggest (yet - I've only read it so 
> far, not spent a lot of time experimenting and searching, so I may be able to 
> implement what I think is a solution to what you wrote, but I doubt it'll be 
> what you expect).

AFAIU, you don't need to juggle with macros as ob-shell does. Something
similar to `org-babel-expand-src-block' will do.

-- 
Ihor Radchenko // yantar92,
Org mode contributor,
Learn more about Org mode at <https://orgmode.org/>.
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