Method on

packages/core/src/createActor.ts:468–488

(
    type: TType,
    handler: (
      emitted: EmittedFrom<TLogic> &
        (TType extends '*' ? unknown : { type: TType })
    ) => void
  )

  }

  public on<TType extends EmittedFrom<TLogic>['type'] | '*'>(
    type: TType,
    handler: (
      emitted: EmittedFrom<TLogic> &
        (TType extends '*' ? unknown : { type: TType })
    ) => void
  ): Subscription {
    let listeners = this.eventListeners.get(type);
    if (!listeners) {
      listeners = new Set();
      this.eventListeners.set(type, listeners);
    }
    const wrappedHandler = handler.bind(undefined);
    listeners.add(wrappedHandler);

    return {
      unsubscribe: () => {
        listeners.delete(wrappedHandler);
      }
    };
  }

  public select<TSelected>(
    selector: (snapshot: SnapshotFrom<TLogic>) => TSelected,