Code Fragment: parenPrint

void parenPrint(const Tree& T, const Position& v) {
  cout << v.element();					// print node's element
  if (T.isInternal(v)) {
    PositionIterator children = T.children(v);
    cout << "( ";					// open
    parenPrint(T, children.next());			// visit the first child
    while (children.hasNext()) {			// for each other child
      cout << ", ";					// print separator
      parenPrint(T, children.next());			// visit the next child
    }
    cout << " )";					// close
  }
}