X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2FAtom.java;h=55be283096ef76586322e63cff8d98b3e03ee535;hb=45d799349e635f1a99e3974e4504a43d5a7aaf33;hp=1b9c25430f017f039c0701c74feed92cfc73736a;hpb=6caa23ec64fa689a91c0b81238d04ff7322a945c;p=sbp.git

diff --git a/src/edu/berkeley/sbp/Atom.java b/src/edu/berkeley/sbp/Atom.java
index 1b9c254..55be283 100644
--- a/src/edu/berkeley/sbp/Atom.java
+++ b/src/edu/berkeley/sbp/Atom.java
@@ -8,38 +8,51 @@ 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> {
+public abstract class Atom<T> extends Element implements Topology<T> {
 
-    private final Topology<T> rt;
-
-    public Atom(Topology<T> rt) { this.rt = 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();
+    protected abstract Topology<T> top();
+    public    abstract String toString();
+    public             StringBuffer toString(StringBuffer sb) { sb.append(this); return sb; }
 
     // 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 //////////////////////////////////////////////////////////////////////////////
+
+    /** an atom which tracks the possible tokenset of some element, provided that element can only match single-token sequences */
+    public static class Infer<T extends Input> extends Atom<T> {
+        private final Element e;
+        public Infer(Element e) { this.e = e; }
+        public Topology<T> top() { return (Topology<T>)toAtom(e); }
+        public String toString() { return e.toString(); }
+    }
     
+    /** an atom which tracks the inverse of some other atom */
+    public static class Invert<T extends Input> 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; }
+    }
+
+    static Topology toAtom(Element e) {
+        if (e instanceof Atom) return (Atom)e;
+        if (e instanceof Sequence) return ((Sequence)e).toAtom();
+        Topology ret = null;
+        for(Sequence s : (Union)e)
+            ret = ret==null ? toAtom(s) : ret.union(s.toAtom());
+        return ret;
+    }
 }