-public abstract class Atom<T extends Token> extends Element {
-
- private final Topology<T> rt;
-
- public Atom(Topology<T> rt) { this.rt = rt; }
-
- Topology<T> top() { return rt; }
-
- void reachable(HashSet<Sequence.Position> h) { /* do-nothing */ }
-
- /** equality is based on the underlying <tt>Topology</tt> */
- public int hashCode() { return rt.hashCode(); }
+public abstract class Atom<T extends Token> extends Element implements Topology<T> {
+
+ protected abstract Topology<T> top();
+ public abstract String toString();
+
+ public Topology toAtom() { return this; }
+
+ // Topology Thunks //////////////////////////////////////////////////////////////////////////////
+
+ public Topology<T> unwrap() { return top().unwrap(); }
+ public Topology<T> empty() { return top().empty(); }
+ public boolean contains(T v) { return top().contains(v); }
+ public Topology<T> intersect(Topology<T> t) { return top().intersect(t); }
+ public Topology<T> minus(Topology<T> t) { return top().minus(t); }
+ public Topology<T> union(Topology<T> t) { return top().union(t); }
+ public Topology<T> complement() { return top().complement(); }
+ public boolean disjoint(Topology<T> t) { return top().disjoint(t); }
+ public boolean containsAll(Topology<T> t) { return top().containsAll(t); }
+ public int hashCode() { return top().hashCode(); }
+ public boolean equals(Object o) { return o != null && o instanceof Atom && ((Atom)o).top().equals(top()); }
+
+ // Subclasses //////////////////////////////////////////////////////////////////////////////
+
+ public static class Infer<T extends Token> extends Atom<T> {
+ private final Element e;
+ public Infer(Element e) { this.e = e; }
+ public Topology<T> top() { return (Topology<T>)e.toAtom(); }
+ public String toString() { return e.toString(); /* FIXME should be toAtom() */ }
+ }
+
+ public static class Invert<T extends Token> extends Atom<T> {
+ private final Atom<T> a;
+ public Invert(Atom<T> a) { this.a = a; }
+ public Topology<T> top() { return ((Topology<T>)a.top()).complement(); }
+ public String toString() { return "~"+a; }
+ }
+
+ public static class Hack<T extends Token> extends Atom<T> {
+ private final Atom<T> a;
+ static final Topology leftright =
+ edu.berkeley.sbp.misc.CharToken.rightBrace.union(edu.berkeley.sbp.misc.CharToken.leftBrace);
+ public Hack(Atom<T> a) { this.a = a; }
+ public Topology<T> top() { return ((Topology<T>)a.top()).minus(leftright); }
+ public String toString() { return "~"+a; }
+ }