Add support for simpler (Callable) hooks (issue #2917)
diff --git a/system/core/Hooks.php b/system/core/Hooks.php
index f6eff4b..767dc4c 100644
--- a/system/core/Hooks.php
+++ b/system/core/Hooks.php
@@ -154,7 +154,16 @@
 	 */
 	protected function _run_hook($data)
 	{
-		if ( ! is_array($data))
+		// Closures/lambda functions and array($object, 'method') callables
+		if (is_callable($data))
+		{
+			is_array($data)
+				? $data[0]->{$data[1]}()
+				: $data();
+
+			return TRUE;
+		}
+		elseif ( ! is_array($data))
 		{
 			return FALSE;
 		}