SequentialComposition.scala

package com.samstarling.futures

import com.twitter.util.Future

object SequentialComposition extends App {

  case class User(name: String)

  def authenticate(credentials: String) = Future { Some(User("sam")) }

  def getTweets(user: User) = Future { List("1", "2", "3") }
  
  val future = for {
    user <- authenticate("foo")
    tweets <- getTweets(user)
  } yield (user, tweets)

  future onSuccess { case (user, tweets) =>
    println(s"The tweets for $user are: $tweets")
  }
}