anchor.diff:    (let* ((name (or (symbol-string-at-point (current-point))
                      (read-symbol-name "Edit uses of: ")))
            (data (lisp-eval `(swank:xrefs '(:calls :macroexpands :binds
  -                                           :references :sets :specializes)
  -                                         ,name))))
  +                                          :references :sets :specializes)
  +                                        ,name))))
       (loop
         :for (type . definitions) :in data
         :for defs := (definitions-to-locations definitions)
  
positive.code:         *edit-definition-stack*))
  
  (defun definition-to-location (definition)
    (optima:match definition
      ((list title
             (list :location
                   (list :file file)
                   (list :position position)
                   (list :snippet _)))
       (return-from definition-to-location
         (make-xref-location :title title
                             :filespec file
                             :position (1+ position))))
      ((list :location
             (list :file file)
             (list :position position)
             (list :snippet _))
       (return-from definition-to-location
         (make-xref-location :title ""
                             :filespec file
                             :position (1+ position))))))
  
  (defun definitions-to-locations (definitions)
    (loop :for def :in definitions
  
negative.code:      (let ((xref-location (source-location-to-xref-location source-location)))
         (go-to-location xref-location t)))))
  
  (defun source-location-to-xref-location (location &optional (title ""))
    (alexandria:destructuring-ecase location
      ((:location location-buffer position _hints)
       (declare (ignore _hints))
       (let ((buffer (location-buffer-to-buffer location-buffer)))
         (with-point ((point (buffer-point buffer)))
           (move-to-location-position point position)
           (make-xref-location :title title
                               :filespec buffer
                               :position (position-at-point point)))))
      ((:error message)
       (editor-error "~A" message))))
  
  