On 11/6/2023 12:11 PM, Ihor Radchenko wrote:
[ Branching to emacs-devel for further input from Emacs devs ]
Jim Porter <[email protected]> writes:
This is similar to Emacs bug#66752[1]. It would be nice if
"(thing-at-point 'url)" would return the URL when point is over an Org
link. With this, it's easier to write a function that copies (or browses
to) the URL at point without coding so many special cases.
...
+(defun org--url-at-point ()
+ "`thing-at-point' provider function."
+ (org-element-property :raw-link (org-element-context)))
Supporting thingatpt.el is certainly welcome. However, I have some
doubts about how mature thingatpt.el is.
In particular, I am concerned whether `thing-at-point-provider-alist' is
reliable enough in non-trivial scenarios like when given URL string is
not matching some generic URL regexp.
The nice thing about 'thing-at-point-provider-alist' is that your
provider has absolute control over what to return, so Org's URL provider
could do whatever it wants. As far as I can tell, this code path
completely avoids calling 'bounds-of-thing-at-point' ('botap'). However,
it *would* call 'botap' if point wasn't on an Org link, since it would
fall back to the last condition in 'thing-at-point'. Still, this is what
happens today with no provider, so it's not really any worse than before...
Maybe it would make sense for 'thing-at-point' to have a "(catch
'not-found ...)" form around the loop over
'thing-at-point-provider-alist'. Then Org could definitively say,
"There's no URL at point, no matter what anyone else says".
Looking into the source code of `bounds-of-thing-at-point', I see that
for standard "things" (like url),
`thing-at-point-bounds-of-url-at-point' is used unconditionally. In the
case of Org links, we may have something like [<point>[https://orgmode.org]]
that will not match default URL regexp as is. AFAIU, there is no
documented way to customize the behaviour of `bounds-of-thing-at-point'
and `forward-thing'.
I think it would make sense to add some sort of
'bounds-of-thing-at-point-provider-alist' (that's a mouthful!) that
would let modes override the behavior of 'botap', but I don't think
that's necessary for the narrower purpose of asking, "I want the value
of THING at point, if any."
I also have concerns about Org-specific part of the patch, but the above
is far more important, and we need to discuss it before starting to
consider anything for Org mode.
For better or worse, I mostly modeled this patch on how EWW integrates
with thing-at-point, since that's the only place I saw in the Emacs tree
that did this already.
