syndicate-2017/racket/syndicate/examples/actor/box-and-client.rkt

20 lines
729 B
Racket

#lang syndicate
;; Simple mutable box and count-to-infinity box client.
(struct set-box (new-value) #:transparent)
(struct box-state (value) #:transparent)
(spawn (field [current-value 0])
(assert (box-state (current-value)))
(stop-when-true (= (current-value) 10)
(log-info "box: terminating"))
(on (message (set-box $new-value))
(log-info "box: taking on new-value ~v" new-value)
(current-value new-value)))
(spawn (stop-when (retracted (observe (set-box _)))
(log-info "client: box has gone"))
(on (asserted (box-state $v))
(log-info "client: learned that box's value is now ~v" v)
(send! (set-box (+ v 1)))))