anchor.diff:  (define-command find-references () ()
     (alexandria:when-let (fn (variable-value 'find-references-function :buffer))
       (let ((refs (funcall fn (current-point))))
  -      (show-references refs))))
  +      (display-xref-references refs))))
   
   (defvar *xref-stack-table* (make-hash-table :test 'equal))
   (defvar *xref-history-table* (make-hash-table :test 'equal))
  
positive.code:   (alexandria:when-let (fn (variable-value 'find-definitions-function :buffer))
      (funcall fn (current-point))))
  
  (defun show-references (refs)
    (unless refs
      (editor-error "No references found"))
    (push-location-stack (current-point))
  
negative.code:    :xref-filespec-to-filename
     :move-to-xref-location-position
     :indent-size
     :display-xref-locations
     :display-xref-references)
    #+sbcl
    (:lock t))
  (in-package :lem.language-mode)
  