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 306e126..0a8ad12 100644 (file)
--- a/src/edu/berkeley/sbp/Atom.java
+++ b/src/edu/berkeley/sbp/Atom.java
@@ -7,12 +7,19 @@ import edu.berkeley.sbp.util.*;
 import edu.berkeley.sbp.*;
 import edu.berkeley.sbp.*;
 
-/** <font color=green>an element which matches exactly one input token</font> */
+/**
+ *  <font color=green>an element which matches some set of one-token-long input strings</font>.
+ *
+ *  This class is a topology over itself so that Atoms can be
+ *  intersected and unioned with each other to result in other
+ *  Atom<T>'s (rather than raw Topology<T>'s, which are not Elements).
+ *  If you want the latter, use the getTokenTopology() method.
+ */
 public abstract class Atom<T> extends Element implements Topology<Atom<T>> {
 
-    public  abstract Topology<T>  underlying();
-    public  abstract String       toString();
-    public           StringBuffer toString(StringBuffer sb) { sb.append(this); return sb; }
+    /** the set (topology) of tokens that can match this element */
+    public abstract Topology<T>  getTokenTopology();
 
+    public abstract StringBuffer toString(StringBuffer sb);
 }