mitsuse

import scala.util.parsing.combinator._

class Tree[L](val label: L, val children: Seq[Tree[L]]) extends Traversable[Tree[L]] {
    val numOfChildren = children.length

    def this(label: L) = this(label, Seq[Tree[L]]())

    override def toString: String = {
        if (isTerminal) {
            return label.toString