PHP7 Specification

Behavioral/Specification/NotSpecification.php

@@ -0,0 +1,21 @@
+<?php
+
+namespace DesignPatterns\Behavioral\Specification;
+
+class NotSpecification implements SpecificationInterface
+{
+    /**
+     * @var SpecificationInterface
+     */
+    private $specification;
+
+    public function __construct(SpecificationInterface $specification)
+    {
+        $this->specification = $specification;
+    }
+
+    public function isSatisfiedBy(Item $item): bool
+    {
+        return !$this->specification->isSatisfiedBy($item);
+    }
+}