Re: [PATCH] Async session eval (2nd attempt)

[TEC]

Hi Jack,

I love the look of this! Thanks for submitting a patch.

Sorry it's taken so long for someone to take a look at it, I think a lot
of the 'main' Org people have been pretty busy over the last few months.

I just tried to give this a shot.
First up, I had to remove the ORG-NEWS part of the patch to be able to
provide it. It would be nice if you could update the patch so this
applies cleanly.

#+begin_example
error: patch failed: etc/ORG-NEWS:88
error: etc/ORG-NEWS: patch does not apply
#+end_example

To test this, after applying your patch (with ORG-NEWS removed), I
started emacs -Q, loaded Org, and opened a new file.

I was initially unable to get this to seem to work, until I changed the
:results type to "output".

See a excerpt from my test file below:

----- excerpt start -----

#+begin_src python :async :session blah :results output
from time import sleep

a=2

sleep(2)
print("Hi")
#+end_src

#+RESULTS:
: Hi

#+begin_src python :async :session blah
return(a)
#+end_src

#+RESULTS:
: /tmp/babel-62cQRX/python-EfJ4o4

#+begin_src python :async :session blah :results output
print(a)
#+end_src

#+RESULTS:
: 2

----- excerpt end -----


I'm surprised this didn't work with the non-output block though.

Other than this, I'm rather happy to see that when I tried to execute
two long running blocks at once, the second one was not executed until
the first completed :)

Finally, I see that this requires :session to be set in order to work.
Might it be possible to have this work for non-session blocks too? It
seems odd that what I'd imagine is the harder case (session blocks) is
supported, but one-shot (non-session) blocks aren't.

Thanks again for your work, and I look forward to seeing what else you
have in the future!

--
Timothy

p.s. After this is merged, it would be great to see support for other
languages grow :)

Jack Kamm <jackkamm@gmail.com> writes:

> This patch adds asynchronous evaluation for session blocks in
> Python. It also adds functionality to implement async session eval for
> other languages using ob-comint.el.
>
> To test the attached patch, add ":async" to a Python session block
> with a long computation (or "time.sleep") in it. Upon evaluation, your
> Emacs won't freeze to wait for the result -- instead, a placeholder
> will be inserted, and replaced with the true result when it's ready.
>
> I'll note how this is different from some related projects. ob-async
> implements asynchronous evaluation for Babel, but it doesn't work with
> sessions. emacs-jupyter, ein, and ob-ipython all implement
> asynchronous session evaluation, but only for Jupyter kernels. Jupyter
> is great for some cases, but sometimes I prefer to use the built-in
> org-babel languages without jupyter.
>
> The new functionality is mainly implemented in
> `org-babel-comint-async-filter', which I've defined in ob-comint.el,
> and added as a hook to `comint-output-filter-functions'.  Whenever new
> output is added to the comint buffer, the filter scans for an
> indicator token (this is inspired by
> `org-babel-comint-with-output'). Upon encountering the token, the
> filter uses a regular expression to extract a UUID or temp-file
> associated with the result, then searches for the appropriate location
> to add the result to.
>
> This is my 2nd attempt at this patch [0]. I have also ported it to an
> external package [1], but would like to have this functionality in Org
> proper, to permit better code reuse between async and sync
> implementations. The external package also includes an R
> implementation that I regularly use, as well as a Ruby implementation,
> but I've left these out to keep this initial patch smaller, and also I
> need to confirm copyright assignment on the Ruby implementation which
> was externally contributed.
>
> [0] 
> https://orgmode.org/list/87muj04xim.fsf@jaheira.i-did-not-set--mail-host-address--so-tickle-me/
> [1] https://github.com/jackkamm/ob-session-async