Re: Adding support for xref jumping to headers/interfaces

[Dmitry Gutov]

On 26/11/2023 22:37, João Távora wrote:
> On Sun, Nov 26, 2023 at 8:15 PM Dmitry Gutov <dmitry@gutov.dev> wrote:
>
> > Eglot's integration shows that we don't in advance know whether a
> > backend actually supports a specific kind. At least, we cannot know
> > whether that kind is supported for a specific symbol at a given position
> > (my tests with Eglot in the Emacs repo and clangd more than often ended
> > up in "nothing found"). So to provide a list like ("definition/A"
> > "documentation/B" ...) we'd have to first query all available backends
> > about all kinds for the symbol at point. I think somebody said that this
> > can be slow at least for some kind/backend/ls combinations.
>
> Who?  Was it me?  If so (I don't think so), I take it back.  This is
> absolutely fine.  Eglot takes this list, from the capabilities reported
> at the start of the LSP session and is very fast.

What I'm saying is that *actually fetching* those might be slow 
(allegedly) for some combinations of kind/backend/ls.

And to implement the kind of fallback Felician described, it seems we 
would first have to know what actual kinds of definitions are available 
for a given reference before providing the aforementioned. For optimal 
user experience, at least.

The Elisp backend actually does that (only show the applicable kinds), 
but Eglot returns a fixed list for all symbols.

> > > > 2. Whether Eglot should, in time, deprecate its corresponding three
> > > > commands if Xref adds its own versions.
> > >
> > > I think one of João's design goals of Eglot is to rely on existing Emacs
> > > features as much as possible.
> >
> > That was my expectation indeed, but lately he said that since the
> > commands are already in Eglot, they will remain there.
>
> This is not my argument, as you well know.

It was one of your explanations, among others, and it was one that I 
understood best.

But one of the latest emails mentioned a separate Xref backend for c/c++ 
-- should I assume that every such backend would define its own set of 
*-find-* commands suitable for its languages?

Would such backends each come with an automatically-enabled keymap? Or 
would the user have to set up key bindings for every such command, for 
every special backend like that?