Charles Berry <ccberry@ucsd.edu> writes:

> Rainer M Krug <Rainer <at> krugs.de> writes:
>
>> 
>> Sebastien Vauban <sva-news@...>
>> writes:
>> 
>> > Rainer M Krug wrote:
>> >> Charles Berry <ccberry@...> writes:
>> >>> Rainer M Krug <Rainer <at> krugs.de> writes:
>> >>>> 
>> >>>> when exporting the fillowing org file, I get an endless loop of
>> >>>> evaluations.
>> >>>> 
>> >>>> --8<---------------cut here---------------start------------->8---
>> >>>> #+PROPERTY: header-args :exports both
>> >>>> #+PROPERTY: header-args+ :results output
>> >>>> * The bug
>> >>>> This file create an (possibly endless?) loop during export
>> >>>> * here exports both
>> >>>> #+begin_src R 
>> >>>> cat(13+14)
>> >>>> #+end_src
>> >>>> 
>> >>>> * and here only code
>> >>>> :PROPERTIES:
>> >>>> :header-args+: exports code
>> >>>> :END:
>> >>>> #+begin_src R 
>> >>>> paste(13+14)
>> >>>> #+end_src
>> >>>> --8<---------------cut here---------------end--------------->8---
>> >>>
>
> [discussion of problem, diagnostic methods, and cures deleted]
>
>
>> 1) I thought that header-args is simply a string, but it already seems
>> to be a list?
>
> Depends on which `header-args' one is discussing:
>
> 1. A property, as in `(org-entry-get (point) "header-args" t)'
>
> 2. The value of `(nth 2 (org-babel-get-src-block-info))'
>
> 3. The value of an elisp variable like `org-babel-default-header-args'
>
> 4. The 4th string matched by `org-babel-src-block-regexp' 
>
> 5. The first string matched by `org-babel-multi-line-header-regexp'
>
> 1, 4 and 5 are strings. 2 and 3 are lists.

Wow - there are many...

But this helps quite a bit.

>
>> 
> [more questions deleted]
>> 
>
> Exactly what happens and when is a long story, involving a bunch of 
> functions.
>
> You might start by reading `org-babel-get-src-block-info' and 
> `org-babel-merge-params'.
>
> I think most of what you need to know really is in 
>
>    (info "(org) Using header arguments")
> and
>    (info "(org) Property syntax")
>
> Just remember that a property called `header-args' is a string until Babel 
> starts working on it.

So your original code, returns the "property called 'header-args'",
(1) while your function below returns the one from 2) above. That
clarifies.

>
>
>> 5) Is there any way in getting, in this function, the same output
>> (header-args) as from the code block suggested by Charles:
>> 
>
> You might try

Thanks - but I was thinking about the ot=her way round, how I could get
the "property called 'header-args'" (1) within the function called when
using C-c C-v C-i to help in debugging - found a way of doing it and
will send a patch.

> #+BEGIN_SRC emacs-lisp :results pp
>    (cons (org-entry-get (point) "header-args" t)
>          (nth 2 (org-babel-get-src-block-info)))
> #+END_SRC
>
> HTH,

Most definitely,

Thanks,

Rainer

>
> Chuck
>
>
>

-- 
Rainer M. Krug
email: Rainer<at>krugs<dot>de
PGP: 0x0F52F982