Hi Dmitry:
Thanks for your work on xref.el. I agree that the API could use some work and it will be better. One thing that would help would be better separation between finding xrefs (which should just return lists of them) and displaying xrefs. For example, I went looking for a generic xref equivalent to find-tag-noselect and the only thing I found was something specific to elisp tags. Shouldn't there be something like xref-find-definitions that only returns a list of definitions and does not display them?
Also, there seem to be many functions that just call a single other functions, creating a deeply nested tree of calls. Is there a way to simplify that?
I also see that about a year ago there was a call for documenting xref.el. Has any progress been made on that? Even though things will change, writing the documentation will give you a base that you can adapt as the library evolves and will help people to provide further feedback.
Just some thoughts.
Bob