PState-example2.scala

trait UserService {
  def updateScoreCard(user: User, event: PointScoredEvent): User
}

val userService: UserService = getUserService()
val userState: PState[User] = getUserState()
val updatedState: PState[User] = userState.map { user =>
  userService.updateScoreCard(user, event)
}

def applyEvent(event: PointScoredEvent): FPState[User] = {
  val futureOptUserState: FOPState[User] =
    userRepo retrieve User.usernameKey(event.username)
  futureOptUserState flatMap { optUserState =>
    val userState: PState[User] = optUserState getOrElse {
      throw new UserNotFoundException(event.username)
    }
    val updatedState: PState[User] =
      userState map userService.updateUser
    userRepo update updatedState
  }
}