sampleStream34.scala

object Sample2 {
  val notificationStream : Stream[(String,String)] = Stream.empty
  object db {
    def findOrder(id:String) : Stream[{def accountId:String}] = Stream.empty
    def findAccount(id:String) : Stream[{def email:String}] = Stream.empty
    def updateAccount(id:Any) : Stream[Boolean] = Stream.empty
    def updateOrder(id:Any) : Stream[Boolean] = Stream.empty
  }
  object email {
    def send(id:String,n:String) : Stream[Boolean] = Stream.empty
  }
  notificationStream.flatMap { tuple=>
    db.findOrder(tuple._1).map(o => (o, tuple._2))
  }.flatMap { tuple=>
    db.updateOrder(tuple._1)
    db.findAccount(tuple._1.accountId).map(o => (o, tuple._2))
  }.flatMap { tuple=>
    db.updateAccount(tuple._1)
    email.send(tuple._1.email, tuple._2);
  }
}