Re: [PATCH 03/10] Clean up various org-babel-*-maybe commands

[Eric Schulte <schulte.eric@gmail.com>]

Aaron Ecay <aaronecay@gmail.com> writes:

> Hi Bastien,
>
> Thanks for your comments.
>
> 2013ko apirilak 3an, Bastien-ek idatzi zuen:
>
> [...]
>
>>> org-babel-get-src-block-info is a potentially expensive operation, which
>>> is why its ‘light’ argument exists.  But in any case, it is overkill to
>>> query the whole info, if all that is needed is whether point is in a
>>> block or not.  Factor the simplified common code out into a macro.
>> 
>> The let-bound info variable is not only used to check if we are within
>> a src block, it is also passed as an argument to functions, see the ^^
>> marks below.
>
> All of these functions will re-calculate the info if it is not
> passed, using org-babel-get-src-block-info.  So not passing it does no
> harm.
>

Could re-calculating the info cause referenced blocks to be executed
more than once?

If so then we should continue passing the info and *not* simply
re-calculate it later on.

Cheers,

>
>> 
>>> ---
>>> lisp/ob-core.el | 31 +++++++++++++++++--------------
>>> 1 file changed, 17 insertions(+), 14 deletions(-)
>>> 
>>> diff --git a/lisp/ob-core.el b/lisp/ob-core.el
>>> index 723aa9d..283628e 100644
>>> --- a/lisp/ob-core.el
>>> +++ b/lisp/ob-core.el
>>> @@ -365,15 +365,22 @@ of potentially harmful code."
>>> (or (org-babel-execute-src-block-maybe)
>>> (org-babel-lob-execute-maybe)))
>>> 
>>> +(defmacro org-babel-when-in-src-block (&rest body)
>>> +  `(if (or (org-babel-where-is-src-block-head)
>>> +           (org-babel-get-inline-src-block-matches))
>>> +       (progn
>>> +	 ,@body
>>> +	 t)
>>> +     nil))
>> 
>> (Please always add a docstring of defuns and defmacros)
>
> I’ll resend the patch with a docstring and fixing the commit message
> problems you and Achim pointed out.
>
>
> [...]
>
>
>>> @@ -433,8 +436,8 @@ then run `org-babel-load-in-session'."
>>> Detect if this is context for a org-babel src-block and if so
>>> then run `org-babel-pop-to-session'."
>>> (interactive)
>>> -  (let ((info (org-babel-get-src-block-info)))
>>> -    (if info (progn (org-babel-pop-to-session current-prefix-arg info) t) nil)))
>>                                                                     ^^^^
>>> +  (org-babel-when-in-src-block
>>> +   (org-babel-pop-to-session current-prefix-arg)))
>> 
>> (Let's use the current name `org-babel-switch-to-session' instead of
>> the obsolete alias.)
>
> OK.
>
>> 
>> Maybe we don't always need to pass the info as an argument, but at
>> least for this last example it is needed.
>
> o-b-switch-to-session does nothing with the info argument but pass it
> along to o-b-initiate-session, which will recalculate it if it is
> missing.  So it takes 2 hops in contrast to the 1 in the other cases,
> but it still gets recalculated.

-- 
Eric Schulte
http://cs.unm.edu/~eschulte