}
private static Expr transform(XMLQuery q) {
Stack stack = new Stack();
for (Iterator i = q.getWhereElementSet().iterator(); i.hasNext();) {
QueryElement e = (QueryElement) i.next();
String keyword = e.getValue();
String type = e.getRole();
if ("elemName".equals(type))
stack.push(keyword);
else if ("LITERAL".equals(type))
stack.push(keyword);
else if ("RELOP".equals(type))