1 files changed, 23 insertions, 0 deletions
diff --git a/src/NXP/Classes/Token/InterfaceFunction.php b/src/NXP/Classes/Token/InterfaceFunction.php
new file mode 100644
index 0000000..be867b0
--- /dev/null
+++ b/src/NXP/Classes/Token/InterfaceFunction.php
@@ -0,0 +1,23 @@
+<?php
+/**
+ * This file is part of the MathExecutor package
+ *
+ * (c) Alexander Kiryukhin
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code
+ */
+
+namespace NXP\Classes\Token;
+
+/**
+ * @author Alexander Kiryukhin <alexander@symdev.org>
+ */
+interface InterfaceFunction
+{
+    /**
+     * @param array $stack
+     * @return $this
+     */
+    public function execute(&$stack);
+}