Fiber Alternative distributivity

FiberDistributivity.scala

import cats._
import cats.effect._
import scala.concurrent.duration._
import cats.implicits._
import scala.language.higherKinds

implicit val ctx = 
  IO.contextShift(scala.concurrent.ExecutionContext.global)
  
implicit val timer = 
  IO.timer(scala.concurrent.ExecutionContext.global)



val a = IO(println("Hi!"))
val b = IO.sleep(1.second) *> IO(println("Whatup?"))
val c = IO.sleep(2.seconds) *> IO(println("Fine"))

def par[F[_], A](x: Fiber[F, A], y: Fiber[F, A])(implicit F: Concurrent[F]): Fiber[F, (A, A)] = {
  type Fib[A] = Fiber[F, A]
  Applicative[Fib].map2(x, y)((a, b) => (a, b))
}
  

def race[F[_], A](x: Fiber[F, A], y: Fiber[F, A])(implicit F: Concurrent[F]): Fiber[F, A] =
  Fiber(
    F.racePair(x.join, y.join).flatMap {
      case Left((a, fib)) => F.as(fib.cancel, a)
      case Right((fib, a)) => F.as(fib.cancel, a)
    },
    F.map2(x.cancel, y.cancel)((_, _) => ()))

val x = for {
  fibA <- a.start
  fibB <- b.start
  fibC <- c.start
  _ <- par(fibA, race(fibB, fibC)).join
} yield ()

val y = for {
  fibA <- a.start
  fibB <- b.start
  fibC <- c.start
  _ <- race(par(fibA, fibB), par(fibA, fibC)).join
} yield ()