eitherT.scala

import scalaz._
import Scalaz._

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

object Main extends App {
  val getEitherTFutures1: Seq[EitherT[Future, Throwable, String]] = {
    Seq(
      EitherT[Future, Throwable, String](Future.apply(\/-("hoge"))),
      EitherT[Future, Throwable, String](Future.apply(\/-("hoge"))),
      EitherT[Future, Throwable, String](Future.apply(\/-("hoge")))
    )
  }

  val getEitherTFutures2: Seq[EitherT[Future, Throwable, String]] = {
    Seq(
      EitherT[Future, Throwable, String](Future.apply(\/-("hoge"))),
      EitherT[Future, Throwable, String](Future.apply(\/-("hoge"))),
      EitherT[Future, Throwable, String](Future.apply(-\/(new Exception)))
    )
  }

  val res1 = getEitherTFutures1.toList.sequenceU // EitherT[Future, Throwable, List[String]]
  val res2 = getEitherTFutures2.toList.sequenceU // EitherT[Future, Throwable, List[String]]

  Await.result(res1.run.map(_.map(println)), Duration.Inf) // List(hoge, hoge, hoge)
  Await.result(res2.run.map(e => println(e.left)), Duration.Inf) // -\/(-\/(java.lang.Exception))
}