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();
14 public abstract String toString();
16 public Topology toAtom() { return this; }
18 // Topology Thunks //////////////////////////////////////////////////////////////////////////////
20 public Topology<T> unwrap() { return top().unwrap(); }
21 public Topology<T> empty() { return top().empty(); }
22 public boolean contains(T v) { return top().contains(v); }
23 public Topology<T> intersect(Topology<T> t) { return top().intersect(t); }
24 public Topology<T> minus(Topology<T> t) { return top().minus(t); }
25 public Topology<T> union(Topology<T> t) { return top().union(t); }
26 public Topology<T> complement() { return top().complement(); }
27 public boolean disjoint(Topology<T> t) { return top().disjoint(t); }
28 public boolean containsAll(Topology<T> t) { return top().containsAll(t); }
29 public int hashCode() { return top().hashCode(); }
30 public boolean equals(Object o) { return o != null && o instanceof Atom && ((Atom)o).top().equals(top()); }
32 // Subclasses //////////////////////////////////////////////////////////////////////////////
34 public static class Infer<T extends Token> extends Atom<T> {
35 private final Element e;
36 public Infer(Element e) { this.e = e; }
37 public Topology<T> top() { return (Topology<T>)e.toAtom(); }
38 public String toString() { return e.toString(); /* FIXME should be toAtom() */ }
41 public static class Invert<T extends Token> extends Atom<T> {
42 private final Atom<T> a;
43 public Invert(Atom<T> a) { this.a = a; }
44 public Topology<T> top() { return ((Topology<T>)a.top()).complement(); }
45 public String toString() { return "~"+a; }
48 public static class Hack<T extends Token> extends Atom<T> {
49 private final Atom<T> a;
50 static final Topology leftright =
51 edu.berkeley.sbp.misc.CharToken.rightBrace.union(edu.berkeley.sbp.misc.CharToken.leftBrace);
52 public Hack(Atom<T> a) { this.a = a; }
53 public Topology<T> top() { return ((Topology<T>)a.top()).minus(leftright); }
54 public String toString() { return "~"+a; }