summaryrefslogtreecommitdiff
path: root/includes/MappedIterator.php
diff options
context:
space:
mode:
Diffstat (limited to 'includes/MappedIterator.php')
-rw-r--r--includes/MappedIterator.php96
1 files changed, 96 insertions, 0 deletions
diff --git a/includes/MappedIterator.php b/includes/MappedIterator.php
new file mode 100644
index 00000000..b4376f44
--- /dev/null
+++ b/includes/MappedIterator.php
@@ -0,0 +1,96 @@
+<?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();
+ }
+}