Many editors allow a mouse-click operation on an identifier, plus a
suitable modifier key, to jump to the declaration of the symbol. Emacs
provides xref-find-definitions-at-mouse, but I couldn't find a way to make
it work in response to a click. So I wrote this variant that works nicely
for me. Notably, it is an (interactive) command, and it doesn't use
save-excursion.

(defun xref-find-definitions-at-mouse-2 (event)
  "Find the definition of identifier at or around mouse click.
This command is intended to be bound to a mouse event."
  (interactive "e")
  (let ((identifier
          (progn
           (mouse-set-point event)
           (xref-backend-identifier-at-point (xref-find-backend)))))
    (if identifier
       (xref-find-definitions identifier)
      (user-error "No identifier here"))))

;; cmd-click -> jump to definition
(global-set-key (kbd "s-<mouse-1>") #'xref-find-definitions-at-mouse-2)

Could this functionality (not necessarily this code) be added to
Emacs's xref package? I am not enough of an Emacs expert to know whether I
was simply "holding it wrong", so perhaps this is merely a documentation
problem.

thanks
alan