public function exportList(Array $list) {
    $that = $this;
    return
      sprintf('array(%s)', A::implode($list, ',', function ($item) use($that) {
        if (is_array($item)) {
          return $that->exportList($item);
        } elseif($item instanceof \stdClass) {
          return $that->exportStdClass($item, 'list'); 
        } else {
          return $that->exportValue($item);
        }
      })
    );
  }