intl库中的gettext（）等效项？

namespace Example;
class Intl {

  private $resource;

  public function __construct() {
    $bundle_location = \"./locales\";
    $user_locale = \\Locale::acceptFromHttp( $_SERVER[\'HTTP_ACCEPT_LANGUAGE\'] );
    $this->resource = new \\ResourceBundle( $user_locale, $bundle_location );
  }

 ...

 use Example\\Intl;

 $intl = new Intl();
 $r = $intl->resource;

 echo $r[\'string_to_be_translated\'];

 ...

locales

root { 
  string_to_be_translated {String to be translated } 
}

ja { 
  string_to_be_translated {\\u5909\\u63DB\\u3055\\u308C\\u308B\\u6587\\u5B57\\u5217 }
}

sp { 
  string_to_be_translated {Cadena a ser traducido }
}