Aaron Ecay <aarone...@gmail.com> writes:
> Hi Eric
>
> 2013ko martxoak 31an, Eric Schulte-ek idatzi zuen:
>>
>> Hi,
>>
>> I've been wanting to add the ability to post-process the results of a
>> code block for some time, and some recent threads (e.g., [1] and [2])
>> could both have benefited from post-processing of code block output.
>
> This looks very nice!
>
>>
>> Does this new header argument seem useful? Any suggestions for better
>> syntax which don't add too much conceptual or code complexity?
>
> See below.
>
>> @@ -625,6 +626,11 @@ block."
>> (not (listp result)))
>> (list (list result)) result))
>> (funcall cmd body params)))
>> + ;; possibly perform post process provided its appropriate
>> + (when (cdr (assoc :post params))
>> + (let ((*this* result))
>> + (setq result (org-babel-ref-resolve
>> + (cdr (assoc :post params))))))
>
> What if you did some string surgery on the :post string, to insert
> ",data=\"the result\"" into the call? That way users could just write
> :post add-width(width=5cm), which would be automatically transformed
> into add-width(width=5cm,data="[[graph.png]]") before being passed to
> o-b-ref-resolve.
>
I don't like this idea, because then it becomes "magic" which value is
assigned the result of the current code block, rather than the current
case in which it is very explicit.
>
> (I guess you’d have to take special care to handle things like ":post
> no-args()" and ":post no-args" properly, stripping the initial comma in
> the first case and adding parens in the second.)
>
> This requires that all :post code blocks take a data
> argument, but I don’t think that’s more onerous than stipulating the
> *this* variable at the lisp level.
>
I think it is more onerous, I also think it reduces flexibility (the
writing of the called block needs to know exactly which argument will
want to be set by later code blocks).
>
> Also, I’m unclear on whether elisp is supported
Yes it is
> (or should be)
Yes again
> . Do we want to allow ":post (message *this*)"?
Yes again
If your issue is that (identity *this*) is cumbersome, then I would
agree. What about if we change `org-babel-read' as with the attached
patch s.t. *any* variable with ear-muffs will be read as Emacs Lisp,
allowing this simpler alternative.
#+name: val-wrap
#+begin_src sh :input="" :results verbatim
echo "--------------------"
echo "$input"
echo "--------------------"
#+end_src
#+begin_src sh :post val-wrap(input=*this*)
echo "foo"
#+end_src
#+RESULTS:
: --------------------
: foo
: --------------------
Cheers,
--
Eric Schulte
http://cs.unm.edu/~eschulte
