added a note to get an extension reference

diff --git a/lib/Twig/Node/Expression/ExtensionReference.php b/lib/Twig/Node/Expression/ExtensionReference.php
new file mode 100644 (file)
index 0000000..bef9da7
--- /dev/null
+++ b/lib/Twig/Node/Expression/ExtensionReference.php
@@ -0,0 +1,38 @@
+<?php
+
+/*
+ * This file is part of Twig.
+ *
+ * (c) 2009 Fabien Potencier
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+/**
+ * Represents an extension call node.
+ *
+ * @package    twig
+ * @author     Fabien Potencier <fabien.potencier@symfony-project.com>
+ * @version    SVN: $Id$
+ */
+class Twig_Node_Expression_ExtensionReference extends Twig_Node_Expression
+{
+    public function __construct($name, $lineno, $tag = null)
+    {
+        parent::__construct(array(), array('name' => $name), $lineno, $tag);
+    }
+
+    /**
+     * Compiles the node to PHP.
+     *
+     * @param Twig_Compiler A Twig_Compiler instance
+     */
+    public function compile($compiler)
+    {
+        $compiler
+            ->addDebugInfo($this)
+            ->raw(sprintf("\$this->env->getExtension('%s')", $this['name']))
+        ;
+    }
+}