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authorPierre Schmitz <pierre@archlinux.de>2014-12-27 15:41:37 +0100
committerPierre Schmitz <pierre@archlinux.de>2014-12-31 11:43:28 +0100
commitc1f9b1f7b1b77776192048005dcc66dcf3df2bfb (patch)
tree2b38796e738dd74cb42ecd9bfd151803108386bc /includes/libs/MappedIterator.php
parentb88ab0086858470dd1f644e64cb4e4f62bb2be9b (diff)
Update to MediaWiki 1.24.1
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+<?php
+/**
+ * Convenience class for generating iterators from iterators.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ * @author Aaron Schulz
+ */
+
+/**
+ * Convenience class for generating iterators from iterators.
+ *
+ * @since 1.21
+ */
+class MappedIterator extends FilterIterator {
+ /** @var callable */
+ protected $vCallback;
+ /** @var callable */
+ protected $aCallback;
+ /** @var array */
+ protected $cache = array();
+
+ protected $rewound = false; // boolean; whether rewind() has been called
+
+ /**
+ * Build an new iterator from a base iterator by having the former wrap the
+ * later, returning the result of "value" callback for each current() invocation.
+ * The callback takes the result of current() on the base iterator as an argument.
+ * The keys of the base iterator are reused verbatim.
+ *
+ * An "accept" callback can also be provided which will be called for each value in
+ * the base iterator (post-callback) and will return true if that value should be
+ * included in iteration of the MappedIterator (otherwise it will be filtered out).
+ *
+ * @param Iterator|Array $iter
+ * @param callable $vCallback Value transformation callback
+ * @param array $options Options map (includes "accept") (since 1.22)
+ * @throws UnexpectedValueException
+ */
+ public function __construct( $iter, $vCallback, array $options = array() ) {
+ if ( is_array( $iter ) ) {
+ $baseIterator = new ArrayIterator( $iter );
+ } elseif ( $iter instanceof Iterator ) {
+ $baseIterator = $iter;
+ } else {
+ throw new UnexpectedValueException( "Invalid base iterator provided." );
+ }
+ parent::__construct( $baseIterator );
+ $this->vCallback = $vCallback;
+ $this->aCallback = isset( $options['accept'] ) ? $options['accept'] : null;
+ }
+
+ public function next() {
+ $this->cache = array();
+ parent::next();
+ }
+
+ public function rewind() {
+ $this->rewound = true;
+ $this->cache = array();
+ parent::rewind();
+ }
+
+ public function accept() {
+ $value = call_user_func( $this->vCallback, $this->getInnerIterator()->current() );
+ $ok = ( $this->aCallback ) ? call_user_func( $this->aCallback, $value ) : true;
+ if ( $ok ) {
+ $this->cache['current'] = $value;
+ }
+
+ return $ok;
+ }
+
+ public function key() {
+ $this->init();
+
+ return parent::key();
+ }
+
+ public function valid() {
+ $this->init();
+
+ return parent::valid();
+ }
+
+ public function current() {
+ $this->init();
+ if ( parent::valid() ) {
+ return $this->cache['current'];
+ } else {
+ return null; // out of range
+ }
+ }
+
+ /**
+ * Obviate the usual need for rewind() before using a FilterIterator in a manual loop
+ */
+ protected function init() {
+ if ( !$this->rewound ) {
+ $this->rewind();
+ }
+ }
+}