removed illegal use of double-star

[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 9586f72..a5149f2 100644 (file)
--- a/src/edu/berkeley/sbp/Sequence.java
+++ b/src/edu/berkeley/sbp/Sequence.java
@@ -35,8 +35,11 @@ public abstract class Sequence extends Element implements Iterable<Element> {
 
     ////////////////////////////////////////////////////////////////////////////////
 
 
     ////////////////////////////////////////////////////////////////////////////////
 

+    public Topology noFollow() { return null; }
+

     Topology toAtom() {
     Topology toAtom() {

-        if (elements.length!=1) return null;
+        if (elements.length>1) throw new RuntimeException("cannot invoke toAtom() on a Sequence with " + elements.length + " elements: " + this);
+        if (elements.length==0) return null;

         return elements[0].toAtom();
     }
 
         return elements[0].toAtom();
     }