Re: Adding custom providers for thingatpt.el (was: [PATCH] Add support for 'thing-at-point' to get URL at point)

[Ihor Radchenko <yantar92@posteo.net>]

Eli Zaretskii <eliz@gnu.org> writes:

> I think we do want to allow extending of this, but doesn't
> thingatpt.el already provide such capabilities?  For example, I see
> this in bounds-of-thing-at-point:
> ...
>     (cond
>      ((get thing 'bounds-of-thing-at-point)  <<<<<<<<<<<<<<<<<<<<<<<<
>       (funcall (get thing 'bounds-of-thing-at-point)))
>
> Doesn't this provide the extension capabilities you are looking for?
> If not, why not?

Unlike `thing-at-point-provider-alist', which can be buffer-local,
symbol property is always global and setting it would override other
thing providers.

Note how `thing-at-point' uses

(cond
          ((let ((alist thing-at-point-provider-alist)
                 elt result)
             (while (and alist (null result))
               (setq elt (car alist)
                     alist (cdr alist))
               (and (eq (car elt) thing)
                    (setq result (funcall (cdr elt)))))
             result))
          ((get thing 'thing-at-point)
           (funcall (get thing 'thing-at-point)))

checking `thing-at-point-provider-alist' and only then falling back to
`get'. What I am proposing is to add the equivalent alists for other
operators used by thingatpt.el.

-- 
Ihor Radchenko // yantar92,
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