diff --git a/projects/viztool/src/java/com/samskivert/viztool/enum/ClassEnumerator.java b/projects/viztool/src/java/com/samskivert/viztool/enum/ClassEnumerator.java
index e07fc2dd..0e48a301 100644
--- a/projects/viztool/src/java/com/samskivert/viztool/enum/ClassEnumerator.java
+++ b/projects/viztool/src/java/com/samskivert/viztool/enum/ClassEnumerator.java
@@ -1,5 +1,5 @@
 //
-// $Id: ClassEnumerator.java,v 1.1 2001/06/14 20:57:15 mdb Exp $
+// $Id: ClassEnumerator.java,v 1.2 2001/07/04 18:22:26 mdb Exp $
 
 package com.samskivert.viztool.enum;
 
@@ -14,7 +14,7 @@ import java.util.StringTokenizer;
  * The component enumerators are structured so that new enumerators can be
  * authored for new kinds of classpath component.
  */
-public class ClassEnumerator
+public class ClassEnumerator implements Enumerator
 {
     /**
      * Constructs a class enumerator with the supplied classpath. A set of
@@ -42,8 +42,8 @@ public class ClassEnumerator
 
             } else {
                 try {
-                    System.out.println("Adding [enum=" + enum +
-                                       ", component=" + component + "].");
+//                      System.out.println("Adding [enum=" + enum +
+//                                         ", component=" + component + "].");
                     // construct an enumerator to enumerate this component
                     // and put it on our list
                     _enums.add(enum.enumerate(component));
diff --git a/projects/viztool/src/java/com/samskivert/viztool/enum/Enumerator.java b/projects/viztool/src/java/com/samskivert/viztool/enum/Enumerator.java
new file mode 100644
index 00000000..9fd63ca9
--- /dev/null
+++ b/projects/viztool/src/java/com/samskivert/viztool/enum/Enumerator.java
@@ -0,0 +1,21 @@
+//
+// $Id: Enumerator.java,v 1.1 2001/07/04 18:22:26 mdb Exp $
+
+package com.samskivert.viztool.enum;
+
+/**
+ * An enumerator is used to iterate over a set of classes.
+ */
+public interface Enumerator
+{
+    /**
+     * Returns true if this enumerator has more classes yet to enumerate,
+     * false if all classes have been reported.
+     */
+    public boolean hasMoreClasses ();
+
+    /**
+     * Returns the class name of the next class in the enumeration.
+     */
+    public String nextClass ();
+}
diff --git a/projects/viztool/src/java/com/samskivert/viztool/enum/FilterEnumerator.java b/projects/viztool/src/java/com/samskivert/viztool/enum/FilterEnumerator.java
new file mode 100644
index 00000000..1e653140
--- /dev/null
+++ b/projects/viztool/src/java/com/samskivert/viztool/enum/FilterEnumerator.java
@@ -0,0 +1,68 @@
+//
+// $Id: FilterEnumerator.java,v 1.1 2001/07/04 18:22:26 mdb Exp $
+
+package com.samskivert.viztool.enum;
+
+/**
+ * The filter enumerator provides the framework by which a particular
+ * subset of classes can be filtered from the total enumeration of classes
+ * in a classpath. This is useful for doing things like only considering
+ * classes in a particular package or only considering interfaces, and so
+ * on.
+ */
+public abstract class FilterEnumerator implements Enumerator
+{
+    /**
+     * Constructs a filter enumerator with the supplied class enumerator
+     * as the source of classes.
+     */
+    public FilterEnumerator (ClassEnumerator source)
+    {
+        _source = source;
+        // we'd love to call scanToNextClass() here but that calls
+        // filterClass() and it's extremely bad form to call a function
+        // provided by a derived class in the super class's constructor
+        // because the derived class's constructor hasn't yet been
+        // executed. sigh.
+    }
+
+    public boolean hasMoreClasses ()
+    {
+        if (_nextClass == null) {
+            scanToNextClass();
+        }
+        return _nextClass != null;
+    }
+
+    public String nextClass ()
+    {
+        if (_nextClass == null) {
+            scanToNextClass();
+        }
+        String clazz = _nextClass;
+        _nextClass = null;
+        scanToNextClass();
+        return clazz;
+    }
+
+    protected void scanToNextClass ()
+    {
+        while (_source.hasMoreClasses()) {
+            String clazz = _source.nextClass();
+            if (!filterClass(clazz)) {
+                _nextClass = clazz;
+                break;
+            }
+        }
+    }
+
+    /**
+     * Derived classes should override this method and return true if the
+     * specified class should be filtered (meaning it should be excluded
+     * from the classes returned) or false if it should be included.
+     */
+    protected abstract boolean filterClass (String clazz);
+
+    protected ClassEnumerator _source;
+    protected String _nextClass;
+}
diff --git a/projects/viztool/src/java/com/samskivert/viztool/enum/PackageEnumerator.java b/projects/viztool/src/java/com/samskivert/viztool/enum/PackageEnumerator.java
new file mode 100644
index 00000000..c65e3187
--- /dev/null
+++ b/projects/viztool/src/java/com/samskivert/viztool/enum/PackageEnumerator.java
@@ -0,0 +1,45 @@
+//
+// $Id: PackageEnumerator.java,v 1.1 2001/07/04 18:22:26 mdb Exp $
+
+package com.samskivert.viztool.enum;
+
+/**
+ * The package enumerator filters out only classes from the specified
+ * package (and subpackages) from the class enumerator provided at
+ * construct time.
+ */
+public class PackageEnumerator extends FilterEnumerator
+{
+    public PackageEnumerator (String pkg, ClassEnumerator source)
+    {
+        super(source);
+        _package = pkg;
+    }
+
+    protected boolean filterClass (String clazz)
+    {
+        return !clazz.startsWith(_package);
+    }
+
+    public static void main (String[] args)
+    {
+        // run ourselves on the classpath
+        String classpath = System.getProperty("java.class.path");
+        ClassEnumerator enum = new ClassEnumerator(classpath);
+        String pkg = "com.samskivert.viztool.enum";
+        PackageEnumerator penum = new PackageEnumerator(pkg, enum);
+
+        // print out the warnings
+        ClassEnumerator.Warning[] warnings = enum.getWarnings();
+        for (int i = 0; i < warnings.length; i++) {
+            System.out.println("Warning: " + warnings[i].reason);
+        }
+
+        // enumerate over whatever classes match our package
+        while (penum.hasMoreClasses()) {
+            System.out.println("Class: " + penum.nextClass());
+        }
+    }
+
+    protected String _package;
+}