Re: Documentation by function beyond elisp

[Augusto Stoffel <arstoffel@gmail.com>]

On Fri, 10 Mar 2023 at 16:50, Eshel Yaron wrote:

> 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,

Right, the LSP protocol doesn't have an interface for anything like
`C-h o'.  You only get information on the symbol at point.

> 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.

The generic Emacs way to provide this functionality is the Info symbol
lookup command `C-h S'.  If your language doesn't have an Info manual
you may have better luck with the `devdocs' package (which I mention as
a shameless but pertinent plug).

Out of curiosity: apart from the issue of availability of documentation
in different formats, is there any prolog-specific logic in
sweeprolog-describe-predicate?