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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 implements Iterator {
/** @var Iterator */
protected $baseIterator;
/** @var Closure */
protected $vCallback;
/**
* 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.
*
* @param Iterator|Array $iter
* @param Closure $vCallback
* @throws MWException
*/
public function __construct( $iter, Closure $vCallback ) {
if ( is_array( $iter ) ) {
$this->baseIterator = new ArrayIterator( $iter );
} elseif ( $iter instanceof Iterator ) {
$this->baseIterator = $iter;
} else {
throw new MWException( "Invalid base iterator provided." );
}
$this->vCallback = $vCallback;
}
/**
* @return void
*/
public function rewind() {
$this->baseIterator->rewind();
}
/**
* @return Mixed|null Returns null if out of range
*/
public function current() {
if ( !$this->baseIterator->valid() ) {
return null; // out of range
}
return call_user_func_array( $this->vCallback, array( $this->baseIterator->current() ) );
}
/**
* @return Mixed|null Returns null if out of range
*/
public function key() {
if ( !$this->baseIterator->valid() ) {
return null; // out of range
}
return $this->baseIterator->key();
}
/**
* @return void
*/
public function next() {
$this->baseIterator->next();
}
/**
* @return bool
*/
public function valid() {
return $this->baseIterator->valid();
}
}
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