X-Git-Url: http://git.megacz.com/?p=sbp.git;a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2FTree.java;h=2ab70c89de063194fdbbb9d3c81b47d8cf6ee511;hp=102817cc073505b48a370061fa333611d8e9e277;hb=fc1e5069ec5401c425dd29b77b04285916b62d10;hpb=c7af09d552a9cf2d53a72baa975c9a73384813ea

diff --git a/src/edu/berkeley/sbp/Tree.java b/src/edu/berkeley/sbp/Tree.java
index 102817c..2ab70c8 100644
--- a/src/edu/berkeley/sbp/Tree.java
+++ b/src/edu/berkeley/sbp/Tree.java
@@ -39,4 +39,7 @@ public class Tree<T> extends PrintableTree<Tree<T>> implements Iterable<Tree<T>>
 
     protected String headToString() { return head==null?null:head.toString(); }
     protected String headToJava()   { return head==null?null:StringUtil.toJavaString(head+""); }
+    protected String left()   { return "{"; }
+    protected String right()  { return "}"; }
+    protected boolean ignoreSingleton() { return false; }
 }