Scala - Custom Iterator

CustomIterator.scala

import scala.collection.AbstractIterator

class CustomIterator[T,U](it: Iterator[T])(f: (T => U)) extends AbstractIterator[U] {
  override def hasNext: Boolean = it.hasNext
  override def next(): U = f(it.next)
}

private def resourceAsStream(resource: String): Iterator[(String, String)] = {
  val stream : java.io.InputStream = getClass.getResourceAsStream(resource)
  val it = scala.io.Source.fromInputStream( stream ).getLines
  val Regex = raw"<([0-9]+)(\s+)(\w+)(\s+)(.+)".r
  new CustomIterator[String, (String,String)](it)({
    s => s match {
      case Regex(seq, _, name, _, m) => (seq, m)
      case _ => null
    }
  })
}

def test() {
  val it = resourceAsStream("/extract_market_data-01.txt")
  it.foreach { s => println(s) }
}