anchor.diff:  (defvar event-manager (new _event-manager))
   (defvar *default-event-module* (aprog1 (new event-module "default")
                                    (event-manager.add !)))
  +(defvar *event-module* *default-event-module*)
  
positive.code: ; tré – Copyright (c) 2008–2015 Sven Michael Klose <pixel@hugbox.org>
  
  (defun bind-event-listener (obj fun)
    (assert (function? fun) "BIND-EVENT-LISTENER requires a function")
  
negative.code: (defmethod _event-manager _bubble (evt init-elm)
    (with (modules         (copy-list _modules)
  		 stopped-modules (make-queue))
      (when (evt.element)
  	  (loop
          (when (evt.element)._hooked?
            (_handle-modules evt (evt.element) modules stopped-modules))
          (!? (| evt._stop
                 (not (evt.bubble)))
              (return !)))
        (unless evt._stop
          (= evt._element init-elm)
          (_handle-modules evt nil modules stopped-modules)))))
  
  (defmethod _event-manager _dispatch (type evt)
    (log-events "Dispatching ~A event on ~A, X: ~A, Y: ~A.~%"
  