gistfile1.scala

class Str(val str: String) extends AnyVal {
  def isEmpty = str == null || str.isEmpty
  def _1 = str.charAt(0)
  def _2 = str.substring(1)
}
object Str {
  def unapply(str: String): Str = new Str(str)
}

object StrTest {
  def remLeadingZeros(str: String): String = str match {
    case "" => ""
    case Str('0', tail) => remLeadingZeros(tail)
    case Str(_, tail) => tail
  }
}