gistfile1.txt

/**
 * In reply to http://blog.xebia.com/2009/07/04/real-world-functional-programming-in-scala-comparing-java-clojure-and-scala/
 */

def opt[T](x: Seq[T]): Seq[T] = if (x == null) Nil else x

def indexed[T](coll: Seq[T]): Seq[(Int, T)] = {
  val c = opt(coll)
  List.range(0,c.length).zip(c.toList)
}

def indexedFilter[T](pred:Seq[T], coll:Seq[T]): Seq[Int] =
  for (p <- opt(pred); idxPair <- indexed(coll); if p == idxPair._2) yield idxPair._1

def indexOfAny[T](pred: Seq[T], coll:Seq[T]): Option[Int] =
  indexedFilter(pred, coll).firstOption