Fixed preg error lookup for all PHP versions

Author: GrahamCampbell

src/Regex/Regex.php

@@ -2,8 +2,6 @@
 
 namespace Dotenv\Regex;
 
-use PhpOption\Option;
-
 class Regex
 {
     /**
@@ -81,20 +79,23 @@ private static function pregAndWrap(callable $operation, $subject)
      */
     private static function lookupError($code)
     {
-        return Option::fromValue(get_defined_constants(true))
-            ->filter(function (array $consts) {
-                return isset($consts['pcre']) && defined('ARRAY_FILTER_USE_KEY');
-            })
-            ->map(function (array $consts) {
-                return array_filter($consts['pcre'], function ($msg) {
-                    return substr($msg, -6) === '_ERROR';
-                }, ARRAY_FILTER_USE_KEY);
-            })
-            ->flatMap(function (array $errors) use ($code) {
-                return Option::fromValue(
-                    array_search($code, $errors, true)
-                );
-            })
-            ->getOrElse('PREG_ERROR');
+        if (defined('PREG_JIT_STACKLIMIT_ERROR') && $code === PREG_JIT_STACKLIMIT_ERROR) {
+            return 'JIT stack limit exhausted';
+        }
+
+        switch ($code) {
+            case PREG_INTERNAL_ERROR:
+                return 'Internal error';
+            case PREG_BAD_UTF8_ERROR:
+                return 'Malformed UTF-8 characters, possibly incorrectly encoded';
+            case PREG_BAD_UTF8_OFFSET_ERROR:
+                return 'The offset did not correspond to the beginning of a valid UTF-8 code point';
+            case PREG_BACKTRACK_LIMIT_ERROR:
+                return 'Backtrack limit exhausted';
+            case PREG_RECURSION_LIMIT_ERROR:
+                return 'Recursion limit exhausted';
+            default:
+                return 'Unknown error';
+        }
     }
 }