Functional Kotlin

Coroutines

Now, let's rework our example with coroutines:

import kotlinx.coroutines.experimental.Deferredimport kotlinx.coroutines.experimental.asyncimport kotlinx.coroutines.experimental.launchimport kotlinx.coroutines.experimental.runBlockingclass CoroutineUserService(private val userClient: UserClient,                     private val factClient: FactClient,                     private val userRepository: UserRepository,                     private val factRepository: FactRepository) : UserService {   override fun getFact(id: UserId): Fact = runBlocking {      val user = async { userRepository.getUserById(id) }.await()      if (user == null) {         val userFromService = async { userClient.getUser(id) }.await()         launch { userRepository.insertUser(userFromService) }         getFact(userFromService)      } else {         async { factRepository ...