;; Stream-Netzwerke

(define (combine proc in-1 in-2 out)
  (spawn
   (lambda ()
     (let loop ()
       (send-sync out
		  (proc (receive-sync in-1)
			(receive-sync in-2)))
       (loop)))))

(define (delay init in out)
  (spawn
   (lambda ()
     (let loop ((message init))
       (send-sync out message)
       (loop (receive-sync in))))))

(define (copy in out-1 out-2)
  (spawn
   (lambda ()
     (let loop ()
       (let ((message (receive-sync in)))
	 (send-sync out-1 message)
	 (send-sync out-2 message)
	 (loop))))))

(define (make-fib-channel)
  (let ((out (make-sync-channel))
	(c1 (make-sync-channel))
	(c2 (make-sync-channel))
	(c3 (make-sync-channel))
	(c4 (make-sync-channel))
	(c5 (make-sync-channel)))

    (delay 0 c4 c5)
    (copy c2 c3 c4)
    (combine + c3 c5 c1)
    (copy c1 c2 out)
    (send-sync c1 1)
    out))