Add an example for multibulk reply iterators.

[ci skip]

examples/MultiBulkReplyIterators.php

@@ -0,0 +1,56 @@
+<?php
+
+/*
+ * This file is part of the Predis package.
+ *
+ * (c) Daniele Alessandri <suppakilla@gmail.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+require 'SharedConfigurations.php';
+
+// Operations such as LRANGE, ZRANGE and others can potentially generate replies
+// containing a huge number of items. In some corner cases, such replies might
+// end up exhausting the maximum allowed memory allocated for a PHP process.
+// Multibulk iterators can be handy because they allow you to stream multibulk
+// replies using plain old PHP iterators, making it possible to iterate them with
+// a classic `foreach` loop and avoiding to consume an excessive amount of memory.
+//
+// PS: please note that multibulk iterators are supported only by the standard
+// connection backend class (Predis\Connection\StreamConnection) and not the
+// phpiredis-based one (Predis\Connection\PhpiredisConnection).
+
+// Create a client and force the connection to use iterable multibulk responses.
+$client = new Predis\Client($single_server + array('iterable_multibulk' => true));
+
+// Prepare an hash with some fields and their respective values.
+$client->hmset('metavars', array('foo' => 'bar', 'hoge' => 'piyo', 'lol' => 'wut'));
+
+// By default multibulk iterators iterate over the reply as a list of items...
+foreach ($client->hgetall('metavars') as $index => $item) {
+    echo "[$index] $item\n";
+}
+
+/* OUTPUT:
+[0] foo
+[1] bar
+[2] hoge
+[3] piyo
+[4] lol
+[5] wut
+*/
+
+// ... but certain multibulk replies are better represented as lists of tuples.
+foreach ($client->hgetall('metavars')->asTuple() as $index => $kv) {
+    list($key, $value) = $kv;
+
+    echo "[$index] $key => $value\n";
+}
+
+/* OUTPUT:
+[0] foo => bar
+[1] hoge => piyo
+[2] lol => wut
+*/