Re: Can you automatically noweb include?

[Tom Gillespie <tgbugs@gmail.com>]

After a bit of investigation, it seems that wallyqs implementation of
ob-racket does not treat/manage :prologue arguments correctly, which
is worrying because I would assume that the semantics for how prologue
works should not be something that could be accidentally broken by
ob-* implementations (but that is a separate issue). More relevant to
this thread is that python the prologue works as others have reported,
but if you include a noweb reference in the prologue it does not get
expanded. It is quite possible that this should be considered a bug
since it means that prologues are added only after the main block is
expanded. This seems incorrect, and I suspect that it is another bug
related to the one fixed in df5a83637518ad9aa586d49884a6271f11afc592
(discussion here
https://orgmode.org/list/CA+G3_PNi3uMvBiWgBdKuC3C6VJt1T1j-RKH43LRqYbr+4NS8ZA@mail.gmail.com/).
The fact that prologue is not expanded means that you can modify what
code is run by putting it in a prologue and org mode will be none-the
wiser. The sha1 changes if you set :cache yes, which means that
something in the execution code is doing something different than in
the block hashing code. Further investigation required.

* Use the code
:PROPERTIES:
:header-args:python: :prologue "<<python-helper>>"
:END:

#+name: python-helper
#+begin_src python
asdf = lambda : 'result'
#+end_src

#+begin_src python :noweb yes
return asdf()
#+end_src

On Fri, Aug 7, 2020 at 9:20 PM Tom Gillespie <tgbugs@gmail.com> wrote:
>
> Hah, this is what I get for not reading carefully enough. I wonder if
> it is possible to stick <<racket-helper>> in the prologue and have it
> expand.
>
> On Fri, Aug 7, 2020 at 9:18 PM Tom Gillespie <tgbugs@gmail.com> wrote:
> >
> > I don't see a direct answer to the original question in the thread, so
> > here is an example of how I do it taken from
> > https://raw.githubusercontent.com/SciCrunch/sparc-curation/master/docs/developer-guide.org.
> > You can ctrl-f for racket-graph-helper to see the relevant blocks. A
> > reduced version is below. Recall that I use
> > https://github.com/wallyqs/ob-racket. I use this pattern all over the
> > place in my org blocks. Best,
> > Tom
> >
> > * Use the code
> > :cache yes"
> > #+begin_src racket :lang racket/base :noweb yes
> > <<racket-helper>>
> > (helper-function "this should work")
> > #+end_src
> >
> > #+RESULTS:
> > : this should work hello world
> >
> >
> > * Define the helpers
> > #+name: racket-helper
> > #+header: :prologue "#lang racket/base"
> > #+begin_src racket :lang racket/base
> > (define (helper-function arg)
> >   (string-append arg " hello world"))
> > #+end_src