Re: [babel] howto debug #+call lines

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

Andreas Leha <andreas.leha@med.uni-goettingen.de> writes:

> Hi Eric,
>
>
>> Andreas Leha <andreas.leha@med.uni-goettingen.de> writes:
>>
>>> Hi Eric,
>>>
>>>> Andreas Leha <andreas.leha@med.uni-goettingen.de> writes:
>>>>
>>>>> Hi all,
>>>>>
>>>>> I am getting different results from the evaluation of a source block and
>>>>> the evaluation of a #+call line to that block.
>>>>>
>>>>> Therefore, my question: Is there an equivalent to
>>>>> org-babel-expand-src-block (C-c C-v v) for #+call lines?
>>>>>
>>>>> Or more general:  How do I debug #+call lines?
>>>>>
>>>>> Regards,
>>>>> Andreas
>>>>>
>>>>
>>>> Can you provide a minimal example?
>>>>
>>>> You could write a code block equivalent to the call line.  E.g.,
>>>>
>>>>     #+call: foo(bar=1)
>>>>
>>>> is equivalent to
>>>>
>>>>     #+begin_src emacs-lisp :var results=foo(bar=1)
>>>>       results
>>>>     #+end_src
>>>
>>> Thanks for following this up.  I found the problem in my case:  The
>>> header argument ':colnames yes' was missing from the call line, such that
>>> the passed variables were different.  (I've fallen into that trap
>>> repeatedly, but do not learn, as it seems...)
>>>
>>> It would have been a lot easier to find this, if I had had the possibility
>>> to do C-c C-v v on the call line to get the chance to step through the
>>> (R-) code that is evaluated.  Without this, it took me some time to
>>> figure things out.
>>>
>>> So the question still stands: Is there the possibility to see what is
>>> actually executed with a call line, similar to C-c C-v v on a source
>>> block?
>>>
>>
>> There is no body to expand in a call line so C-c C-v v would have
>> nothing to show.  You can however jump to the related code block and
>> call C-c C-v v there.  This process could be made faster by wrapping the
>> org-babel-goto-named-src-block and org-babel-expand-src-block functions
>> into a single function.
>>
>>
>>>
>>> For a small example consider:
>>>
>>> ---
>>> #+name: foo
>>> | bar |
>>> | baz |
>>> | bam |
>>>
>>> #+call: testblock[:var a=foo]() :colnames yes
>>>
>>> #+name: testblock
>>> #+begin_src R :var a=foo :colnames yes
>>>   a <- a[,1]
>>>   data.frame(x=a)
>>> #+end_src
>>> ---
>>>
>>> Regards,
>>> Andreas
>>>
>>>
>
> Thanks for the confirmation, that there is no possibility to expand a
> #+call line.
>
> I know, that I can jump to the code block and expand that one (quite
> fast with C-c C-v g RET C-c C-v v), but that is exactly *not* what I was
> looking for.  Because then, the header arguments to the source code
> block will apply instead of the header arguments to the #+call line.
>
> I was hoping for a C-c C-v v on #+call lines, which would spare me from
> modifying the source block's header arguments.  But it is not a pressing
> issue, just my laziness (and bad coding perhaps).
>

Patches are always welcome. :)

The call line is evaluated by first expanding itself into a full code
block, so perhaps you could add functionality to C-c C-v v so that it
will expand this ephemeral code block.  Additionally it may be easy to
update C-c C-v I so that it works on call lines, which may provide the
information you're after.

Best,

>
> Regards,
> Andreas
>
>
>

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