add hashable Objects

src/Common/Interfaces/IHashable.php

@@ -0,0 +1,33 @@
+<?php
+declare(strict_types=1);
+/**
+ * MIT License
+ *
+ * Copyright (c) 2018 Dogan Ucar, <dogan@dogan-ucar.de>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+namespace doganoo\PHPAlgorithms\Common\Interfaces;
+
+interface IHashable {
+
+    public function getHash(): string;
+
+}

src/Common/Util/MapUtil.php

@@ -28,8 +28,10 @@
 
 use doganoo\PHPAlgorithms\Common\Exception\InvalidKeyTypeException;
 use doganoo\PHPAlgorithms\Common\Exception\UnsupportedKeyTypeException;
+use doganoo\PHPAlgorithms\Common\Interfaces\IHashable;
 use function array_walk_recursive;
 use function ceil;
+use function doubleval;
 use function gettype;
 use function is_array;
 use function is_bool;
@@ -83,20 +85,23 @@ public static function normalizeKey($key): int {
          */
         if (is_string($key)) {
             $key = MapUtil::stringToKey($key);
-        } else if (is_object($key)) {
-                $objectString = MapUtil::objectToString($key);
-                $key          = MapUtil::stringToKey($objectString);
+        } else if ($key instanceof IHashable) {
+            $key = $key->getHash();
+            $key = MapUtil::stringToKey($key);
+        } else if (is_object($key) && !($key instanceof IHashable)) {
+            $objectString = MapUtil::objectToString($key);
+            $key          = MapUtil::stringToKey($objectString);
         } else if (is_array($key)) {
-                    $arrayString = MapUtil::arrayToKey($key);
-                    $key         = MapUtil::stringToKey($arrayString);
+            $arrayString = MapUtil::arrayToKey($key);
+            $key         = MapUtil::stringToKey($arrayString);
         } else if (is_double($key)) {
-                        $key = MapUtil::doubleToKey($key);
+            $key = MapUtil::doubleToKey($key);
         } else if (is_float($key)) {
-            $key = MapUtil::doubleToKey(\doubleval($key));
+            $key = MapUtil::doubleToKey(doubleval($key));
         } else if (is_bool($key)) {
-                                $key = MapUtil::booleanToKey($key);
+            $key = MapUtil::booleanToKey($key);
         } else if (is_resource($key) || $key === null) {
-                                    $key = MapUtil::booleanToKey(true);
+            $key = MapUtil::booleanToKey(true);
         } else if (is_int($key)) {
             return $key;
         } else {

tests/Table/Entity/HashableObject.php

@@ -0,0 +1,43 @@
+<?php
+declare(strict_types=1);
+/**
+ * MIT License
+ *
+ * Copyright (c) 2018 Dogan Ucar, <dogan@dogan-ucar.de>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+namespace doganoo\PHPAlgorithmsTest\Table\Entity;
+
+use doganoo\PHPAlgorithms\Common\Interfaces\IHashable;
+
+class HashableObject implements IHashable {
+
+    private $id;
+
+    public function __construct($id) {
+        $this->id = $id;
+    }
+
+    public function getHash(): string {
+        return $this->id;
+    }
+
+}

tests/Table/HashTableTest.php

@@ -26,7 +26,9 @@
 
 namespace doganoo\PHPAlgorithmsTest\Table;
 
+use doganoo\PHPAlgorithms\Common\Interfaces\IHashable;
 use doganoo\PHPAlgorithms\Datastructure\Table\HashTable;
+use doganoo\PHPAlgorithmsTest\Table\Entity\HashableObject;
 use doganoo\PHPAlgorithmsTest\Util\HashTableUtil;
 use PHPUnit\Framework\TestCase;
 use stdClass;
@@ -160,11 +162,33 @@ public function testClosure(): void {
         $this->assertTrue($added);
         $added = $hashMap->add("test2", new class {
 
-            public function x():void {
+            public function x(): void {
             }
 
         });
         $this->assertTrue($added);
     }
 
+    public function testHashableObject(): void {
+        $obj   = new HashableObject("1");
+        $table = new HashTable();
+        $table->put($obj, "1");
+
+        $this->assertTrue($table->size() === 1 && $table->get($obj) === "1");
+
+        $obj2 = new HashableObject("1");
+        $table->put($obj2, "2");
+        $this->assertTrue($table->size() === 1 && $table->get($obj) === "2");
+
+        $table->put("1", "3");
+        $this->assertTrue(
+            $table->size() === 2
+            && $table->get($obj) === "2"
+            && $table->get("1") === "3"
+        );
+
+        $this->assertInstanceOf(IHashable::class, $table->keySet()[0]);
+        $this->assertTrue(is_string($table->keySet()[1]));
+    }
+
 }