self

self is implicitly bound inside an actor. Use self to pass a reference to the current actor to another actor. self is never needed to reference to the current actor within the current actor.

Source:

actor Pinger(ponger: Ponger):
    def pong(message: str):
        print("Pinger: Got pong:", message)

    print("Pinger: Sending ping to Ponger...")
    ponger.ping(self)

actor Ponger():
    def ping(pinger: Pinger):
        print("Ponger: Got ping!")
        # Call back to the pinger
        pinger.pong("Hello from Ponger!")

# Usage
actor main(env):
    ponger = Ponger()
    pinger = Pinger(ponger)

    env.exit(0)

Output:

Pinger: Sending ping to Ponger...
Ponger: Got ping!
Pinger: Got pong: Hello from Ponger!

In this example, Pinger passes self to Ponger when pinging, allowing the ponger to send a pong back.