Complete Applications

To make the example in Figure ``Counter'' a complete MrEd application, we need to add the following definition:

  (define mred:startup
    (lambda args
      (make-object pb-counted-session%)))

When MrEd is started with this program (with the -u and -f flags), then mred:startup will be invoked, creating a phone book search session, which in turn creates a frame. When the user presses the ``Quit'' button, the frame will be closed. Since no more frames are open, the application will exit.