1 package edu.berkeley.sbp;
4 import java.lang.reflect.*;
5 import java.lang.ref.*;
6 import edu.berkeley.sbp.util.*;
7 import edu.berkeley.sbp.*;
8 import edu.berkeley.sbp.*;
10 /** an element which matches exactly one input token */
11 public abstract class Atom<T extends Token> extends Element implements Topology<T> {
13 protected abstract Topology<T> top();
15 public Topology toAtom() { return dup(); }
17 /** equality is based on the underlying <tt>Topology</tt> */
18 public int hashCode() { return top().hashCode(); }
20 /** equality is based on the underlying <tt>Topology</tt> */
21 public boolean equals(Object o) { return o != null && o instanceof Atom && ((Atom)o).top().equals(top()); }
23 /** declared abstract to force subclasses to override it in a useful manner */
24 public abstract String toString();
26 // Topology Thunks //////////////////////////////////////////////////////////////////////////////
28 public void add(Topology<T> t) { top().add(t); }
29 public void add(T t) { top().add(t); }
30 public void remove(Topology<T> t) { top().remove(t); }
31 public void remove(T t) { top().remove(t); }
32 public Topology<T> dup() { return top().dup(); }
33 public boolean contains(T v) { return top().contains(v); }
34 public Topology<T> fresh() { return top().fresh(); }
35 public Topology<T> intersect(Topology<T> t) { return top().intersect(t); }
36 public Topology<T> minus(Topology<T> t) { return top().minus(t); }
37 public Topology<T> union(Topology<T> t) { return top().union(t); }
38 public Topology<T> complement() { return top().complement(); }
39 public boolean disjoint(Topology<T> t) { return top().disjoint(t); }
40 public boolean containsAll(Topology<T> t) { return top().containsAll(t); }
42 // Subclasses //////////////////////////////////////////////////////////////////////////////
44 public static class Infer<T extends Token> extends Atom<T> {
45 private final Element e;
46 public Infer(Element e) { this.e = e; }
47 public Topology<T> top() { return (Topology<T>)e.toAtom(); }
48 public String toString() { return e.toString(); }
51 public static class Invert<T extends Token> extends Atom<T> {
52 private final Atom<T> a;
53 public Invert(Atom<T> a) { this.a = a; }
54 public Topology<T> top() { return ((Topology<T>)a.top()).complement(); }
55 public String toString() { return "~"+a; }