xort.scala

import cats.data.{ Xor, XorT }
import cats.std.future._
import cats.syntax.xor._

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

object XorDemo extends App {
  sealed trait Error

  def f1(): Future[Xor[Error, Int]] = {
    Future.successful(3.right)
  }

  def f2(): Future[Xor[Error, Int]] = {
    Future.successful(5.right)
  }

  def f3(): Future[Xor[Error, Int]] = {
    val z = for {
      x <- XorT(f1())
      y <- XorT(f2())
    } yield x + y
    z.value
  }

  println(Await.result(f3(), Duration.Inf))
}