Thanks for your answer!


> You likely need to extend `org-babel-scheme--table-or-string' to
> understand Image: type.
>

It looks to me that when `org-babel-execute:scheme` gets executed, then the
result will not get inserted as a link, as that would require the results
type 'file', right?
From the manual <https://orgmode.org/manual/Results-of-Evaluation.html>, it
seems to me that using the 'file' type is required to get the result
inserted as a link.

However, I can not see how the code does the following as explained in the
manual.

The manual <https://orgmode.org/manual/Results-of-Evaluation.html> states
(under Type/file):

> If ‘file’ header argument is missing, Org generates the base name of the
> output file from the name of the code block, and its extension from the ‘
> file-ext’ header argument. In that case, both the name and the extension
> are mandatory.
>
suggesting that a file gets written also when there is no :file header
argument.

But from the `and` condition here
<https://github.com/bzg/org-mode/blob/bd468136dd1a2172302b3ec980c5e6b6e327d683/lisp/ob-core.el#L820>
in `org-babel-execute-src-block`, it looks to me that a file is only
written when a :file argument is provided (via the `with-temp-file` that
follows within the 'when file ...').
Anyway, this I only found when trying to find out how the result gets
formatted as a link.

I guess to get the racket `Image` file-path to formatted correctly, it
would be preferable to only touch ob-scheme for that. In which case, I
think the 'result' under 'org-babel-result-cond' at the end of
'org-babel-execute:scheme' should get (re)formatted conditionally (when the
results is a racket image (link)).

So in the end, I conclude that maybe the advice as mentioned in my
'original' mail, might be already the 'cleanest' solution (and that it does
not cause any problem concerning a file getting written to disk, as
luckily, org does not seem to write files when no :file header argument is
given). Anyway, I am struggling to find out how to come up with an
alternative clean(er) solution.

On Sun, 18 Dec 2022 at 13:38, Ihor Radchenko <yantar92@posteo.net> wrote:

> dalanicolai <dalanicolai@gmail.com> writes:
>
> > I have not asked anywhere yet, but I do not know a 'standard org-mode'
> way
> > to make org-mode show the plot images. Racket creates a temp image file
> and
> > returns a string that includes the path to the file. The actual format of
> > the string is:
> >
> > "\"#<Image: /var/tmp/geiser-img-16711484841671148484684.png>\""
> >
> > I could create a patch for it, but I am not sure how to best implement it
> > (in a clean way).
>
> You likely need to extend `org-babel-scheme--table-or-string' to
> understand Image: type.
>
> > however, it would be great if support could be added to ob-scheme itself.
> > I would be happy to do it, but as mentioned before I don't think I know
> how
> > to do it in the proper way. I would probably just add a condition around
> the
> > 'result' in 'org-babel-execute:scheme' as follows:
>
> I do not know much about scheme.
>
> Generally, ob-* libraries try their best to convert native language
> types to Elisp. If #<Image: ...> is something that is unambiguously
> identified as image file, I do not see why we cannot support it,
> converting the #<Image: ...> representation to file link. Especially,
> when users request :results file.
>
> --
> Ihor Radchenko // yantar92,
> Org mode contributor,
> Learn more about Org mode at <https://orgmode.org/>.
> Support Org development at <https://liberapay.com/org-mode>,
> or support my work at <https://liberapay.com/yantar92>
>