public abstract class Atom<T> extends Element implements Topology<T> {
protected abstract Topology<T> top();
- public abstract String toString();
+ public abstract String toString();
public StringBuffer toString(StringBuffer sb) { sb.append(this); return sb; }
// Topology Thunks //////////////////////////////////////////////////////////////////////////////
public int hashCode() { return top().hashCode(); }
public boolean equals(Object o) { return o != null && o instanceof Atom && ((Atom)o).top().equals(top()); }
- // Subclasses //////////////////////////////////////////////////////////////////////////////
-
-
+ /** 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();