Rename library/ to src/

We've always considered renaming this directory, as it's not a common
standard to name `library` the directory where the source code of a
library it. Having it as `src/` is a common pattern we find in several
PHP libraries these days.

Acked-by: Alexandre Gomes Gaigalas <alganet@gmail.com>

src/Validators/Control.php

@@ -0,0 +1,41 @@
+<?php
+
+/*
+ * SPDX-License-Identifier: MIT
+ * SPDX-FileCopyrightText: (c) Respect Project Contributors
+ * SPDX-FileContributor: Alexandre Gomes Gaigalas <alganet@gmail.com>
+ * SPDX-FileContributor: Andre Ramaciotti <andre@ramaciotti.com>
+ * SPDX-FileContributor: Danilo Correa <danilosilva87@gmail.com>
+ * SPDX-FileContributor: Graham Campbell <graham@mineuk.com>
+ * SPDX-FileContributor: Henrique Moody <henriquemoody@gmail.com>
+ * SPDX-FileContributor: Nick Lombard <github@jigsoft.co.za>
+ */
+
+declare(strict_types=1);
+
+namespace Respect\Validation\Validators;
+
+use Attribute;
+use Respect\Validation\Message\Template;
+use Respect\Validation\Validators\Core\FilteredString;
+
+use function ctype_cntrl;
+
+#[Attribute(Attribute::TARGET_PROPERTY | Attribute::IS_REPEATABLE)]
+#[Template(
+    '{{subject}} must only contain control characters',
+    '{{subject}} must not contain control characters',
+    self::TEMPLATE_STANDARD,
+)]
+#[Template(
+    '{{subject}} must only contain control characters and {{additionalChars}}',
+    '{{subject}} must not contain control characters or {{additionalChars}}',
+    self::TEMPLATE_EXTRA,
+)]
+final class Control extends FilteredString
+{
+    protected function isValid(string $input): bool
+    {
+        return ctype_cntrl($input);
+    }
+}