Re: Documentation by function beyond elisp

[Eshel Yaron <me@eshelyaron.com>]

Yuri Khan <yuri.v.khan@gmail.com> writes:

> On Fri, 10 Mar 2023 at 16:12, Ihor Radchenko <yantar92@posteo.net> wrote:
>>
>> Yuri Khan <yuri.v.khan@gmail.com> writes:
>>
>> > For languages other than Elisp, this is handled by the language
>> > server. Eglot arranges for language-server-provided function help to
>> > be displayed by ElDoc.
>>
>> What about an equivalent of the *Help* buffer?
>
> Well, what about it? You move the point to an identifier. Its
> signature and a few lines of documentation are shown in the echo area.
> You invoke (eldoc-doc-buffer) and see the whole documentation.
>
> It may be a bit inconvenient that the content of that buffer changes
> as you move point to a different identifier. But that can be worked
> around with (clone-buffer).

IMO ElDoc and Help and two pretty different features, each with its own
use and purpose.  Eglot integrates with ElDoc but not with Help AFAIU,
but language-specific packages can (and should!) integrate with both of
these facilities.  Emacs lets package authors reuse the Help UI pretty
easily.  For example, my package sweeprolog.el (for working with
SWI-Prolog code) provides both ElDoc integration and a command
sweeprolog-describe-predicate that works much like describe-predicate,
it uses the help.el interface to show a proper *Help* buffer with the
documentation of a given Prolog predicate.  References to other
predicates become links to their corresponding *Help* buffers, just like
we have for Elisp.  It even works for user-defined predicates.


Cheers,
Eshel