fork-weirdness.scala

import scalaz._
import concurrent._

// utility for shifting off to a different thread
def thread[A](body: => A)(cb: A => Unit): Unit = {
  val t = new Thread {
    setName("test-thread")
    override def run(): Unit = cb(body)
  }
  
  t.start()
}

// shift to a new thread and return as an async Task
def threadTask[A](body: => A): Task[A] = Task async { cb => thread(body) { a => cb(\/-(a)) } }

// show that we're actually shifting off into a different thread
val name1 = threadTask { Thread.currentThread.getName } run

// shift to a different thread, then fork back into the default pool and check the thread name
val name2 = Task fork (threadTask { () }) >> (Task delay { Thread.currentThread.getName }) run

name1 == name2     // => true;    uh, why?!