Interactive Input

ContinuationsExample.scala

import scala.util.continuations._

// might need to be compiled and run separately due to a bug in App
object ContinuationsExample extends App {
  def prompt(display: String): Boolean = {
    print(display + " (Y/N) ")

    Console.readLine.trim.headOption match {
      case Some('Y') | Some('y') => true
      case Some('N') | Some('n') => false
      case _ => prompt(display)
    }
  }

  def delay(duration: Long) =
    shift {
      k: (Unit => Boolean) =>
        do {
          println("%nSleeping for %d milliseconds..." format (duration))
          Thread.sleep(duration)
        } while (k())
    }

  println("Before reset")

  reset {
    delay(2000)

    prompt("Repeat?")
  }

  println("\nAfter reset")
}