--- /dev/null
+<?php
+/*
+ * This file is part of the Comparator package.
+ *
+ * (c) Sebastian Bergmann <sebastian@phpunit.de>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace SebastianBergmann\Comparator;
+
+/**
+ * Factory for comparators which compare values for equality.
+ */
+class Factory
+{
+ /**
+ * @var Comparator[]
+ */
+ private $comparators = array();
+
+ /**
+ * @var Factory
+ */
+ private static $instance;
+
+ /**
+ * Constructs a new factory.
+ */
+ public function __construct()
+ {
+ $this->register(new TypeComparator);
+ $this->register(new ScalarComparator);
+ $this->register(new NumericComparator);
+ $this->register(new DoubleComparator);
+ $this->register(new ArrayComparator);
+ $this->register(new ResourceComparator);
+ $this->register(new ObjectComparator);
+ $this->register(new ExceptionComparator);
+ $this->register(new SplObjectStorageComparator);
+ $this->register(new DOMNodeComparator);
+ $this->register(new MockObjectComparator);
+ $this->register(new DateTimeComparator);
+ }
+
+ /**
+ * @return Factory
+ */
+ public static function getInstance()
+ {
+ if (self::$instance === null) {
+ self::$instance = new self;
+ }
+
+ return self::$instance;
+ }
+
+ /**
+ * Returns the correct comparator for comparing two values.
+ *
+ * @param mixed $expected The first value to compare
+ * @param mixed $actual The second value to compare
+ * @return Comparator
+ */
+ public function getComparatorFor($expected, $actual)
+ {
+ foreach ($this->comparators as $comparator) {
+ if ($comparator->accepts($expected, $actual)) {
+ return $comparator;
+ }
+ }
+ }
+
+ /**
+ * Registers a new comparator.
+ *
+ * This comparator will be returned by getInstance() if its accept() method
+ * returns TRUE for the compared values. It has higher priority than the
+ * existing comparators, meaning that its accept() method will be tested
+ * before those of the other comparators.
+ *
+ * @param Comparator $comparator The registered comparator
+ */
+ public function register(Comparator $comparator)
+ {
+ array_unshift($this->comparators, $comparator);
+
+ $comparator->setFactory($this);
+ }
+
+ /**
+ * Unregisters a comparator.
+ *
+ * This comparator will no longer be returned by getInstance().
+ *
+ * @param Comparator $comparator The unregistered comparator
+ */
+ public function unregister(Comparator $comparator)
+ {
+ foreach ($this->comparators as $key => $_comparator) {
+ if ($comparator === $_comparator) {
+ unset($this->comparators[$key]);
+ }
+ }
+ }
+}