includes/libs/ReverseArrayIterator.php

   1 <?php
   2 /**
   3  * Convenience class for iterating over an array in reverse order.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @since 1.27
  22  */
  23
  24 /**
  25  * Convenience class for iterating over an array in reverse order.
  26  *
  27  * @since 1.27
  28  */
  29 class ReverseArrayIterator implements Iterator, Countable {
  30         /** @var array $array */
  31         protected $array;
  32
  33         /**
  34          * Creates an iterator which will visit the keys in $array in
  35          * reverse order.  If given an object, will visit the properties
  36          * of the object in reverse order.  (Note that the default order
  37          * for PHP arrays and objects is declaration/assignment order.)
  38          *
  39          * @param array|object $array
  40          */
  41         public function __construct( $array = [] ) {
  42                 if ( is_array( $array ) ) {
  43                         $this->array = $array;
  44                 } elseif ( is_object( $array ) ) {
  45                         $this->array = get_object_vars( $array );
  46                 } else {
  47                         throw new InvalidArgumentException( __METHOD__ . ' requires an array or object' );
  48                 }
  49
  50                 $this->rewind();
  51         }
  52
  53          public function current() {
  54                 return current( $this->array );
  55          }
  56
  57          public function key() {
  58                 return key( $this->array );
  59          }
  60
  61          public function next() {
  62                 prev( $this->array );
  63          }
  64
  65          public function rewind() {
  66                 end( $this->array );
  67          }
  68
  69          public function valid() {
  70                 return key( $this->array ) !== null;
  71          }
  72
  73          public function count() {
  74                 return count( $this->array );
  75          }
  76 }