X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2FAtom.java;h=e02b79f816c0a95039abcf9e67206563cb3e5e4c;hb=61539aaf02d0537fd1df08b5d5bd03189992cf1e;hp=61f120d6fcccdf24e34ab453fa62c5fce26378fb;hpb=242a8711e98cbd3ed6d05271bf910fde38e9be9a;p=sbp.git

diff --git a/src/edu/berkeley/sbp/Atom.java b/src/edu/berkeley/sbp/Atom.java
index 61f120d..e02b79f 100644
--- a/src/edu/berkeley/sbp/Atom.java
+++ b/src/edu/berkeley/sbp/Atom.java
@@ -1,3 +1,5 @@
+// Copyright 2006 all rights reserved; see LICENSE file for BSD-style license
+
 package edu.berkeley.sbp;
 import java.io.*;
 import java.util.*;
@@ -7,55 +9,25 @@ import edu.berkeley.sbp.util.*;
 import edu.berkeley.sbp.*;
 import edu.berkeley.sbp.*;
 
-/** an element which matches exactly one input token */
-public abstract class Atom<T extends Token> extends Element implements Topology<T> {
-
-    protected abstract Topology<T> top();
-
-    void reachable(HashSet<Sequence.Position> h) { /* do-nothing */ }
-
-    public Topology toAtom() { return dup(); }
-
-    /** equality is based on the underlying <tt>Topology</tt> */
-    public int hashCode() { return top().hashCode(); }
-    
-    /** equality is based on the underlying <tt>Topology</tt> */
-    public boolean equals(Object o) { return o != null && o instanceof Atom && ((Atom)o).top().equals(top()); }
+/**
+ *  <font color=green>an element which matches some set of one-token-long input strings</font>.
+ *
+ *  <p>
+ *  This class is a topology over itself (yes, that's sort of <a
+ *  href=http://en.wikipedia.org/wiki/Frege>Frege'd</a> up) so that
+ *  Atoms can be intersected and unioned with each other to result in
+ *  other Atom<Token>'s (rather than raw Topology<Token>'s, which are
+ *  not Elements).  If you want the latter, use the getTokenTopology()
+ *  method.
+ *  </p>
+ */
+public abstract class Atom<Token> extends Element implements Topology<Atom<Token>> {
+
+    /** the set (topology) of tokens that can match this element */
+    public abstract Topology<Token>  getTokenTopology();
+
+    StringBuffer toString(StringBuffer sb) { sb.append(this); return sb; }
 
-    /** declared abstract to force subclasses to override it in a useful manner */
-    public abstract String toString();
-
-    // Topology Thunks //////////////////////////////////////////////////////////////////////////////
-
-    public void              add(Topology<T> t)         { top().add(t); }
-    public void              add(T t)                   { top().add(t); }
-    public void              remove(Topology<T> t)      { top().remove(t); }
-    public void              remove(T t)                { top().remove(t); }
-    public Topology<T>       dup()                      { return top().dup(); }
-    public boolean           contains(T v)              { return top().contains(v); }
-    public Topology<T>       fresh()                    { return top().fresh(); }
-    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); }
-
-    // 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(); }
-    }
-    
-    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; }
-    }
-    
 }
 
+