update copyright date 2006->2007

[sbp.git] / src / edu / berkeley / sbp / misc / StringWalker.java

diff --git a/src/edu/berkeley/sbp/misc/StringWalker.java b/src/edu/berkeley/sbp/misc/StringWalker.java
index 923c639..6f02710 100644 (file)
--- a/src/edu/berkeley/sbp/misc/StringWalker.java
+++ b/src/edu/berkeley/sbp/misc/StringWalker.java
@@ -1,3 +1,5 @@
+// Copyright 2006-2007 all rights reserved; see LICENSE file for BSD-style license
+
 package edu.berkeley.sbp.misc;
 import edu.berkeley.sbp.*;
 import edu.berkeley.sbp.util.*;
@@ -6,7 +8,13 @@ import java.util.*;
 import java.lang.reflect.*;
 
 public abstract class StringWalker extends TreeWalker<String> {
-    public Object walk(Tree<String> tree) { return super.walk(tree); }
+    public void   walk(String tag) { }
+    public Object walk(Tree<String> tree) {
+        Object o = tree.head();
+        if (!(o instanceof String)) o = null; /* FIXME */
+        walk((String)o);
+        return super.walk(tree);
+    }
     public Object walk(String tag, Object[] tokens) {
         if (tokens.length==0) return tag;
         if (tag==null) return null;