public int hashCode() { return top().hashCode(); }
public boolean equals(Object o) { return o != null && o instanceof Atom && ((Atom)o).top().equals(top()); }
- /** if all expressions matching <tt>e</tt> are exactly one token
- * long, <b>attempt to</b> return an Atom representing that token
- * (undecidable in general; only works in trivial cases)
- */
- public static Topology toAtom(Element e) {
- if (e instanceof Atom) return (Atom)e;
- if (e instanceof Sequence) return ((Sequence)e).toAtom();
- Topology ret = null;
- for(Sequence s : (Union)e)
- ret = ret==null ? toAtom(s) : ret.union(s.toAtom());
- return ret;
- }
}