frontend and backend

backend/src/Resource/Functions.php

@@ -0,0 +1,16 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Resource;
+
+/**
+ * Implemented PREG functions.
+ */
+enum Functions: string {
+    case Match = 'preg_match';
+    case MatchAll = 'preg_match_all';
+    case Split = 'preg_split';
+    case Replace = 'preg_replace';
+    case Quote = 'preg_quote';
+}