added Element.toAtom()

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

diff --git a/src/edu/berkeley/sbp/Sequence.java b/src/edu/berkeley/sbp/Sequence.java
index fcff530..9586f72 100644 (file)
--- a/src/edu/berkeley/sbp/Sequence.java
+++ b/src/edu/berkeley/sbp/Sequence.java
@@ -35,6 +35,11 @@ public abstract class Sequence extends Element implements Iterable<Element> {
 
     ////////////////////////////////////////////////////////////////////////////////
 
+    Topology toAtom() {
+        if (elements.length!=1) return null;
+        return elements[0].toAtom();
+    }
+
     protected final Element[] elements;
 
     final HashSet<Sequence> needs;