checkpoint

[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 32e7f0f..6c7a25e 100644 (file)
--- a/src/edu/berkeley/sbp/Atom.java
+++ b/src/edu/berkeley/sbp/Atom.java
@@ -11,7 +11,7 @@ import edu.berkeley.sbp.*;
 public abstract class Atom<T> extends Element implements Topology<T> {
 
     protected abstract Topology<T> top();
-    public    abstract String toString();
+    public    abstract String       toString();
     public             StringBuffer toString(StringBuffer sb) { sb.append(this); return sb; }
 
     // Topology Thunks //////////////////////////////////////////////////////////////////////////////
@@ -28,9 +28,10 @@ public abstract class Atom<T> extends Element implements Topology<T> {
     public int               hashCode()                 { return top().hashCode(); }
     public boolean           equals(Object o)           { return o != null && o instanceof Atom && ((Atom)o).top().equals(top()); }
 
-    // Subclasses //////////////////////////////////////////////////////////////////////////////
-
-    
+    /** if all expressions matching <tt>e</tt> are exactly one token
+     *  long, <b>attempt to</b> return an Atom representing that token
+     *  (undecidable in general; only works in trivial cases)
+     */
     public static Topology toAtom(Element e) {
         if (e instanceof Atom) return (Atom)e;
         if (e instanceof Sequence) return ((Sequence)e).toAtom();