/** @ingroup SPL
 * @brief This Interface allows to hook into the global sort() functions.
 * @since PHP 5.6
 */
interface Sortable
{
  /** Sort the entries by values.
   */
  function sort($sort_flags = SORT_REGULAR);

  /** Sort the entries by values in reverse
   */
  function rsort($sort_flags = SORT_REGULAR);

  /** Sort the entries by values and maintain indexes.
   */
  function asort($sort_flags = SORT_REGULAR);

  /** Sort the entries by values in reverse and maintain indexes.
   */
  function arsort($sort_flags = SORT_REGULAR);

  /** Sort the entries by key.
   */
  function ksort($sort_flags = SORT_REGULAR);

  /** Sort the entries by key in reverse.
   */
  function krsort($sort_flags = SORT_REGULAR);

  /** Sort the entries by values using user defined function.
   */
  function usort(mixed cmp_function);

  /** Sort the entries by values using user defined function and maintain index.
   */
  function uasort(mixed cmp_function);

  /** Sort the entries by key using user defined function.
   */
  function uksort(mixed cmp_function);

  /** Sort the entries by values using "natural order" algorithm.
   */
  function natsort();

  /** Sort the entries by values using case insensitive "natural order" algorithm.
   */
  function natcasesort();

}