add polyfill to for the idn calls

composer.json

@@ -16,9 +16,9 @@
   ],
   "require": {
     "php": ">=5.5",
-    "symfony/polyfill-intl-icu": "^1.0",
     "layershifter/tld-database": "^1.0",
-    "layershifter/tld-support": "^1.1"
+    "layershifter/tld-support": "^1.1",
+    "true/punycode": "^2.1.1"
   },
   "require-dev": {
     "codeclimate/php-test-reporter": "dev-master",
@@ -29,7 +29,8 @@
   },
   "autoload": {
     "files": [
-      "src/static.php"
+      "src/static.php",
+      "src/polyfill.php"
     ],
     "psr-4": {
       "LayerShifter\\TLDExtract\\": "src/"

src/polyfill.php

@@ -0,0 +1,52 @@
+<?php
+/**
+ * TLDExtract: Library for extraction of domain parts e.g. TLD. Domain parser that uses Public Suffix List.
+ *
+ * @link      https://github.com/layershifter/TLDExtract
+ *
+ * @copyright Copyright (c) 2016, Alexander Fedyashov
+ * @license   https://raw.githubusercontent.com/layershifter/TLDExtract/master/LICENSE Apache 2.0 License
+ */
+
+namespace
+{
+    use TrueBV\Punycode;
+
+    if (!function_exists('idn_to_utf8')) {
+
+        /**
+         * Polyfill for idn_to_utf8.
+         *
+         * @link http://php.net/manual/de/function.idn-to-utf8.php
+         *
+         * @param $domain
+         *
+         * @return string
+         */
+        function idn_to_utf8($domain)
+        {
+            $punyCode = new Punycode();
+
+            return $punyCode->encode($domain);
+        }
+    }
+
+    if (!function_exists('idn_to_ascii')) {
+
+        /**
+         * Polyfill for idn_to_ascii.
+         *
+         * @link http://php.net/manual/de/function.idn-to-ascii.php
+         *
+         * @param string $domain
+         *
+         * @return string
+         */
+        function idn_to_ascii($domain)
+        {
+            $punyCode = new Punycode();
+
+            return $punyCode->decode($domain);
+        }
+    }
+}