Re: Xref completion

[Dmitry Gutov]

On 05.12.2020 14:21, William Xu wrote:
> Dmitry Gutov <dgutov@yandex.ru> writes:
>
> > I've pushed it now with some changes, hope you all like the result.
> >
> > Shortening the group part (in most common cases) is among them.
> >
> > Also added some highlighting with corresponding xref faces. It now
> > looks closer to Pierre's original screenshot.
>
> The result looks nice.

Thanks.

> > Removed the bit of logic that hid the summaries when they are
> > technically unnecessary because in my testing it made completion
> > slightly less useful by hiding information (sorry).
>
> If the summary contains different info, like the actual line from the
> group (in case it is a file), that may be useful to show it, for
> example:
>
> /foo.cpp:40:struct Foo : Bar
> /foo2.cpp:42:struct Foo : Foo2

That's how it usually looks in my testing, with the etags backend. E.g.:

Possible completions are:
dispextern.h:2703:  int vpos;
indent.h:29:    EMACS_INT vpos;
window.h:97:  int hpos, vpos;

(After I try to navigate to the definitions 'vpos' from xdisp.c:1499).

Of course, in the end it depends on each backend to put useful into into 
summaries. And in the case of etags, that depends on how the definition 
is written (that the identifier is not alone on its line).

> However, at the moment it only shows the same summary info for each
> line, which doesn't seem really useful:
>
> /foo.cpp:40:Foo
> /foo2.cpp:42:Foo

Which backend is this? Also etags?

> Or one can also just add this info into the reading prompt:
>      (format "Jump to definition of `%s': " summary)

I suppose it could be a special case, but we'd have to pipe through the 
initial input as well (it's not currently available). So hopefully there 
is some better solution.