lets_build_a_coroutine__state_update.kt

fun saveUserTasks(userId: Int, state: State) {
    when (state.label) {
        0 -> {
            val user = loadUser(userId)
            println("user loaded")
            state.result = user
            state.label = 1
            return
        }

        1 -> {
            //  resume execution
            val user = state.result as User
            val tasks = loadTasks(user)
            println("tasks loaded")
            state.result = tasks
            state.label = 2
            return
        }

        2 -> {
            //  resume execution
            val tasks = state.result as List<Task>
            saveTasks(tasks)
        }
    }
}