loops.scala

object Loops{
  def loop(cond : =>Boolean)(action : =>Unit){
    try { 
      while(cond){
        try { action } catch { case Continue => }
      }
    } catch { case Break => }
  }

  def foreach[T](its : Iterable[T])(action : T=>Unit){
    try {
      its.foreach{t => 
        try { action(t) } catch { case Continue => }
      }
    } catch { case Break => }
  }

  def foldLeft[S, T](its : Iterable[T], start : S)(f : (S, T) => S) = {
    var s = start;
    foreach(its)(t => s = f(s, t));
    s
  }

  def break = throw Break;
  def continue = throw Continue;

  private object Break extends Error;
  private object Continue extends Error;
}