timeout.scala

object timeout{
  private val _doomsday = new scala.util.DynamicVariable[Long](Long.MaxValue);

  def doomsday = _doomsday.value;
  def timeRemaining = doomsday - System.currentTimeMillis;
  def checkpoint = if (System.currentTimeMillis > _doomsday.value) throw DieNow;

  def timeout[T](time : Long)(t : =>T) : Option[T] = _doomsday.withValue(System.currentTimeMillis + time){
    try { Some(t) } catch { case DieNow => None }
  }

  private[timeout] object DieNow extends Error;    
}