Rename examples and update some comments.

[ci skip]

examples/lua_scripting_abstraction.php

@@ -0,0 +1,71 @@
+<?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 __DIR__.'/shared.php';
+
+// This example will not work with versions of Redis < 2.6.
+//
+// Additionally to the EVAL command defined in the current development profile,
+// the Predis\Command\ScriptCommand class can be used to build an higher level
+// abstraction for "scriptable" commands so that they will appear just like any
+// other command on the client-side. This is a quick example used to implement
+// INCREX.
+
+use Predis\Command\ScriptCommand;
+
+class IncrementExistingKeysBy extends ScriptCommand
+{
+    public function getKeysCount()
+    {
+        // Tell Predis to use all the arguments but the last one as arguments
+        // for KEYS. The last one will be used to populate ARGV.
+        return -1;
+    }
+
+    public function getScript()
+    {
+        return <<<LUA
+local cmd, insert = redis.call, table.insert
+local increment, results = ARGV[1], { }
+
+for idx, key in ipairs(KEYS) do
+  if cmd('exists', key) == 1 then
+    insert(results, idx, cmd('incrby', key, increment))
+  else
+    insert(results, idx, false)
+  end
+end
+
+return results
+LUA;
+    }
+}
+
+$client = new Predis\Client($single_server, array(
+    'profile' => function ($options) {
+        $profile = $options->getDefault('profile');
+        $profile->defineCommand('increxby', 'IncrementExistingKeysBy');
+
+        return $profile;
+    }
+));
+
+$client->mset('foo', 10, 'foobar', 100);
+
+var_export($client->increxby('foo', 'foofoo', 'foobar', 50));
+
+/*
+array (
+  0 => 60,
+  1 => NULL,
+  2 => 150,
+)
+*/