8.8 Local actors

actor Session {
  var cart: Cart = Cart.empty()
  msg add(item: Item) { cart.push(item) }
  msg total() -> Money { cart.sum() }
}

let s = spawn Session()           // ActorRef<Session>
s.add(item) -> s.total() -> show(it)

• Messages are processed strictly one at a time, in the order of arrival from each sender.
• A msg call is suspendable; it completes after the message has been processed and returns the result. For "fire and forget" use ~> or spawn.
• The actor state (var) is accessible only from its msgs. Arguments and results MUST be transferable (§7.3).
• Waiting for another actor inside a msg is allowed; the analyzer marks cyclic waits with a warning.
• Distributed (sharded) actors — §12.5.

Related diagnostics

actor-cycle

Source: docs/spec/oxl-standard.en.md