diff options
author | Pierre Schmitz <pierre@archlinux.de> | 2014-12-27 15:41:37 +0100 |
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committer | Pierre Schmitz <pierre@archlinux.de> | 2014-12-31 11:43:28 +0100 |
commit | c1f9b1f7b1b77776192048005dcc66dcf3df2bfb (patch) | |
tree | 2b38796e738dd74cb42ecd9bfd151803108386bc /includes/libs/MappedIterator.php | |
parent | b88ab0086858470dd1f644e64cb4e4f62bb2be9b (diff) |
Update to MediaWiki 1.24.1
Diffstat (limited to 'includes/libs/MappedIterator.php')
-rw-r--r-- | includes/libs/MappedIterator.php | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/includes/libs/MappedIterator.php b/includes/libs/MappedIterator.php new file mode 100644 index 00000000..7fdde8a8 --- /dev/null +++ b/includes/libs/MappedIterator.php @@ -0,0 +1,117 @@ +<?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(); + } + } +} |