refactoring to eliminate Token.result()

[sbp.git] / src / edu / berkeley / sbp / Atom.java

diff --git a/src/edu/berkeley/sbp/Atom.java b/src/edu/berkeley/sbp/Atom.java
index 8c702a1..aac834b 100644 (file)
--- a/src/edu/berkeley/sbp/Atom.java
+++ b/src/edu/berkeley/sbp/Atom.java
@@ -10,38 +10,40 @@ import edu.berkeley.sbp.*;
 /** an element which matches exactly one input token */
 public abstract class Atom<T extends Token> extends Element implements Topology<T> {
 
-    private final Topology<T> rt;
+    protected abstract Topology<T> top();
+    public    abstract String toString();
 
-    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(); }
-    
-    /** equality is based on the underlying <tt>Topology</tt> */
-    public boolean equals(Object o) { return o != null && o instanceof Atom && ((Atom)o).rt.equals(rt); }
-
-    /** declared abstract to force subclasses to override it in a useful manner */
-    public abstract String toString();
+    public Topology toAtom() { return this; }
 
     // Topology Thunks //////////////////////////////////////////////////////////////////////////////
 
-    public void              add(Topology<T> t)         { rt.add(t); }
-    public void              add(T t)                   { rt.add(t); }
-    public void              remove(Topology<T> t)      { rt.remove(t); }
-    public void              remove(T t)                { rt.remove(t); }
-    public Topology<T>       dup()                      { return rt.dup(); }
-    public boolean           contains(T v)              { return rt.contains(v); }
-    public Topology<T>       fresh()                    { return rt.fresh(); }
-    public Topology<T>       intersect(Topology<T> t)   { return rt.intersect(t); }
-    public Topology<T>       minus(Topology<T> t)       { return rt.minus(t); }
-    public Topology<T>       union(Topology<T> t)       { return rt.union(t); }
-    public Topology<T>       complement()               { return rt.complement(); }
-    public boolean           disjoint(Topology<T> t)    { return rt.disjoint(t); }
-    public boolean           containsAll(Topology<T> t) { return rt.containsAll(t); }
+    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(); }
+    }
+    
+    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; }
+    }
     
 }