Implement HopObject.list(start, length) as proposed by Tobi in

<http://helma.org/bugs/show_bug.cgi?id=303>. This is similar to
HopObject.list(), except the array it returns only contains the child
objects in the range specified by the start and length arguments.
This also does a prefetchChildren() on the specified range to optimize
database access.

src/helma/scripting/rhino/HopObject.java

@@ -452,6 +452,31 @@ public class HopObject extends ScriptableObject implements Wrapper {
         return Context.getCurrentContext().newArray(core.global, a.toArray());
     }
 
+    /**
+     *  Return a JS array of child objects with the given start and length.
+     *
+     * @return A JavaScript Array containing the specified child objexts
+     */
+    public Scriptable jsFunction_list(int start, int length) {
+        if (start < 0 || length < 0) {
+            throw new EvaluatorException("Arguments must not be negative in HopObject.list(start, length)");
+        }
+
+        checkNode();
+
+        jsFunction_prefetchChildren(start, length);
+        ArrayList a = new ArrayList();
+
+        for (int i=start; i<start+length; i++) {
+            INode n = node.getSubnodeAt(i);
+            if (n != null) {
+                a.add(Context.toObject(n, core.global));
+            }
+        }
+
+        return Context.getCurrentContext().newArray(core.global, a.toArray());
+    }
+
     /**
      *
      *