queue-callback

Installs a procedure to be called via the current eventspace's event queue. The procedure is called once in the same way and under the same restrictions that a callback is invoked to handle a method.

A second (optional) boolean argument indicates whether the callback has a high or low priority in the event queue. See Eventspaces for information about the priority of events.

• (queue-callback callback high-priority?) -> void
      callback : procedure of no arguments
      high-priority? = #t : boolean