anchor.diff:  ;; Events
   (defprotocol socket-event-driver (a)
     ((error (driver socket error)
  -    :default-form (drop-connection error)
  +    :default-form nil
       :documentation "Event called when SOCKET has experienced some error. ERROR is the actual
                       condition. This event is executed immediately before the client is shut down.
                       By default, this event simply drops the client connection.
  
positive.code:                                                     end-of-file
                                                      error)
                                                  (lambda (e)
                                                    (on-socket-error (socket-driver socket) e socket))))
                                    (restart-case
                                        (let* ((buffer (socket-read-buffer socket))
                                               (bytes-read
  
negative.code:                     The fact that ON-SOCKET-ERROR receives the actual condition allows a sort of
                      condition handling by specializing both the driver and the condition. For
                      example:
                      (defmethod on-socket-error ((driver my-driver) socket (error end-of-file))
                        (format t \"~&Got an end of file.~%\")
                        (drop-connection error))
  