PitTree.scala

class PitTree[T](val children : Map[String, PitTree[T]], val value : Option[T]) extends Map[String, T] {
  def this() = this(Map(), None)
  def this(value : T) = this(Map(), Some(value))
  def update(path : String, upVal : T) : PitTree[T] = update(splitPath(path), upVal)
  def update(path : List[String], upVal : T) : PitTree[T] = path match {
    case Nil =>
      new PitTree[T](upVal)
    case h :: t =>
      val child = children.getOrElse(h, new PitTree[T]()).update(t, upVal)
      new PitTree[T](children + (h -> child), value)
  }
  def get(path : String) : Option[T] = get(splitPath(path))
  def get(path : List[String]) : Option[T] = path match {
    case Nil =>
      	value
    case h :: t =>
      	if(children.keysIterator.exists(_ == h))
      		children(h).get(t)
        else
        	None
  }
  
  def + [T1 >: T](kv: (String, T1)): PitTree[T] = this  // TODO: Implement me
  def - (key: String): PitTree[T] = this                // TODO: Implement me
  def iterator = Iterator()                             // TODO: Implement me

  def splitPath(path : String) = path.split('/').filter(_ != "").toList

  override def toString = {
	def formatTree(children : Map[String, PitTree[T]], prefix : String) : String = {
	  children.toList.take(children.size).map((pair) => {
		val (path, tree) = pair
	    val valueString = if (tree.value.isDefined) " = " + tree.value.get.toString else " "
	    prefix + path + valueString + "\n" + formatTree(tree.children, prefix + "|`")
	  }
	).mkString}
	formatTree(children, "")
  }
}

object PitTree {
  def apply[T]()                          = new PitTree[T]()
  def apply[T](value : T)                 = new PitTree[T](value)
}

object Test {  
  def main(args: Array[String]) {
    //TODO: Add example with comments showing results of operations.
  }
}