Re: [babel] #+call-line removes hlines and headings ?

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

Marc-Oliver Ihm <marc-oliver.ihm@online.de> writes:

> Am 29.01.2012 11:42, schrieb Andreas Leha:
>> :colnames yes
> Hi Andreas,
>
> Thanx, that is definitely a solution !
>
> And I agree with you, that its a bit puzzling, that both cases behave differently;
> the #+call-line should just have the same result as the #+begin_src-line, to which after all
> it just refers. Beeing able to change the behaviour of the #+call-line
> with header arguments is
> of course a good thing, but it should not be necessary here in the first place.
>
> However, this would require a patch to the babel-code, which I am
> currently not able to produce, because I already
> got lost in debugging this problem :-) And of course I am not sure
> what would be the side effects of changing this
> behaviour ...
>
> So, thanx again for pointing out this very easy workaround !
>
>
> with kind regards, Marc-Oliver Ihm
>

To explain the cause (if not rationale) for the current behavior; when
executing a call line, an ephemeral code block is created at the point
of the call line.  The result of the called function is passed into this
ephemeral block, and the output of the block is inserted into the
buffer.

This is why call lines have *two* possible sets of header arguments, one
to pass to the original called code block, and one for local effect in
the ephemeral block.

The reason the colnames header argument is required for the call line
and not the code block, is because hlines are only stripped when data
passes *into* a code block as a variable.  In this case the 'hlines are
stripped when the table passes into the ephemeral code blocks.

Hope the above is more illuminating that confusing,

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