Future.scala

import scala.concurrent.{Await, Future}
import scala.concurrent.duration._
import scala.concurrent.ExecutionContext.Implicits.global

def ageNextYear(currentAge: Int): Future[Int] = {
  Future { currentAge + 1 }
}

def welcome(name: String, age: Int): Future[String] = {
  Future { s"$name $age" }
}

val f = for {
  age <- ageNextYear(25)
  message <- welcome("Michal", age)
} yield s"$message nextYear: $age"

Await.result(f, 1.second) // Michal 26 nextYear: 26