/*
 * call-seq:
 *  [](tag_name)
 *
 * Get ElemementDescription for +tag_name+
 */
static VALUE get_description(VALUE klass, VALUE tag_name)
{
  const htmlElemDesc * description = htmlTagLookup(
      (const xmlChar *)StringValuePtr(tag_name)
  );

  if(NULL == description) return Qnil;
  return Data_Wrap_Struct(klass, 0, 0, (void *)description);
}