Sealed, not enumerated

Coming from Java, you may be tempted to overload your enum with functionality:

// Java code
enum PizzaOrderStatus {
ORDER_RECEIVED, 
PIZZA_BEING_MADE, 
OUT_FOR_DELIVERY, 
COMPLETED;


    public PizzaOrderStatus nextStatus() {
switch (this) {
case ORDER_RECEIVED: return PIZZA_BEING_MADE;
            case PIZZA_BEING_MADE: return OUT_FOR_DELIVERY;
            case OUT_FOR_DELIVERY: return COMPLETED;
            case COMPLETED:return COMPLETED;
}
    }
}

Instead, you can use the sealed class:

sealed class PizzaOrderStatus(protected val orderId: Int) {
abstract fun nextStatus() : PizzaOrderStatus
class OrderReceived(orderId: Int) : PizzaOrderStatus(orderId) {
override fun nextStatus(): PizzaOrderStatus {
return PizzaBeingMade(orderId)
        }
    }

class PizzaBeingMade(orderId: Int) : PizzaOrderStatus(orderId) {
override fun nextStatus(): PizzaOrderStatus {
return OutForDelivery(orderId)
        }
    }

class OutForDelivery(orderId: Int) : PizzaOrderStatus(orderId) ...