Re: Question about xref and adding "find all references" button to built-in help

[Dmitry Gutov]

On 20.09.2021 08:47, Arthur Miller wrote:
> Dmitry Gutov <dgutov@yandex.ru> writes:
>
> > Hi!
> >
> > On 19.09.2021 23:17, Arthur Miller wrote:
> > > If I would like to add a link as there is one in Helpful, to find all references
> > > for a current symbol in help-mode buffer; which xref functionality should I look
> > > at? Is there a ready made function already, or do I have to write something?
> >
> > We have functionality to searching for references in the current project (also
> > works when inside an Emacs sources checkout) and throughout the load-path.
>
> As extensive as helpful's help-ref? He searches through each and every source
> file found in the load-path. Where do I look, can you give me some pointer I can
> start playing with? Or should I do build my own search?

That's just 'M-x xref-find-references'. Try it in an Elisp buffer.

The implementation is fairly simple: see 'xref-backend-references' in 
xref.el and elisp-load-path-roots.

For your own backend, you will probably not dispatch through project.el 
method, and use load-path directly combined with package-user-dir. Maybe 
after pruning it for entries that reside inside other entries.

> > But you probably want this to work in installed Emacs as well?
>
> What do you mean by "installed Emacs"? Emacs without sources? Sorry, I just woke
> up, have to get that coffein going up :).

Without sources or with compressed sources.

> What about to just have a keyboard shortcuts; say 'R', instead of link. With
> source code displayed it already looks a bit crouded. I think helpfuls buffer
> looks a bit busy with all the links.
>
> I could imagine living with just a shortcut and maybe a context menu item.

I don't really have an opinion on the UI part of this. It can be a 
button, command, whatever.

> I attached a screeshots of helpful and built-in help with my yserdays patch both
> showing source code for the comparison.

UI for references and definitions will probably need to be different, no?