syndicate-2017/racket/syndicate/examples/actor/bank-account.rkt

18 lines
487 B
Racket

#lang syndicate
;; Hello-worldish "bank account" example.
(struct account (balance) #:prefab)
(struct deposit (amount) #:prefab)
(spawn (field [balance 0])
(assert (account (balance)))
(on (message (deposit $amount))
(balance (+ (balance) amount))))
(spawn (on (asserted (account $balance))
(printf "Balance changed to ~a\n" balance)))
(spawn* (until (asserted (observe (deposit _))))
(send! (deposit +100))
(send! (deposit -30)))