Re: Supporting newer Emacs features in older Emacs versions without warnings?

[Basil L. Contovounesios]

Stefan Monnier [2021-09-27 14:38 -0400] wrote:

> Basil L. Contovounesios [2021-09-26 17:49:33] wrote:
>> Stefan Monnier [2021-09-24 09:14 -0400] wrote:
>>> Can you guys come up with an idea of how to change shortdoc.el so that
>>> your package can do its job more easily and cleanly?
>>> [ Ideally without having to use eval-after-load nor having to require
>>> shortdoc.  ]
>>
>> Apart from eval-after-load, what other mechanisms do we have that can
>> register information before a package is loaded?  There's obarray and
>> there are hooks, is there something else?
>
> For buffer-local info, the standard way is for the amjor mode to do
>
>     (setq-local <foo> <bar>)
>
> Example of <foo> include `font-lock-defaults` (back when font-lock was
> not enabled by default), `outline-regexp`, `imenu-generic-expression`, ...
>
> Here I think we want something that's not buffer-local, so we'd need
> something else.  Not sure what's the best option.  Maybe
>
>     (add-hook 'shortdoc-foo-functions #'...)
>
> ?

It faces the same problem: shortdoc somehow needs to know about 'foo'
a priori, for interactive group name completion.

>> The entrypoint command shortdoc-display-group could, every time it is
>> invoked, scan obarray for certain symbol properties, or run a hook, to
>> accumulate auxiliary shortdoc forms, in addition to those that were
>> already permanently stored in shortdoc--groups.
>
> That's also an option, yes (scanning `obarray` is fairly quick).

I'll try to propose something soon™ unless someone beats me to it.

Thanks,

-- 
Basil