package mj.compiler.ast; import java.util.Vector; class Sequence<T extends AST> extends AST { private Vector<T> elements = new Vector<T>(); public Sequence(T element) { // super(element); elements.add(element); } public int length() { return elements.size(); } public T elementAt(int i) { return elements.elementAt(i); } } class AST<T> { public AST() { } public AST(T element) { } }