(import actors)

(enable-trace)

(define ((make-counter-behaviour value) self customer . args)
  (match args
    (('get) (send-message customer value) 'sleep)
    (('inc delta) (make-counter-behaviour (+ value delta)))))

(define println
  (make-actor-with-address 'println
   (lambda (self . message)
     (apply print message)
     'sleep)))
    
(define counter0 (make-actor (make-counter-behaviour 0)))

(send-and-run counter0 println 'get)
(send-message counter0 println 'inc 3)
(send-message counter0 println 'get)
(send-message counter0 println 'inc 2)
(send-and-run counter0 println 'get)