Simplified the translator from an object to a callable

composer.json

@@ -26,6 +26,7 @@
     },
     "autoload-dev": {
         "psr-4": {
+            "Datto\\JsonRpc\\Examples\\": "examples",
             "Datto\\JsonRpc\\Tests\\": "tests"
         }
     }

tests/Example/Stateful/Math.php → examples/Application/Math.php

@@ -22,43 +22,26 @@
  * @copyright 2015 Datto, Inc.
  */
 
-namespace Datto\JsonRpc\Tests\Example\Stateful;
+namespace Datto\JsonRpc\Examples\Application;
 
 class Math
 {
-    public function subtract()
-    {
-        $arguments = func_get_args();
-
-        if (count($arguments) === 1) {
-            // Named arguments
-            $a = @$arguments[0]['minuend'];
-            $b = @$arguments[0]['subtrahend'];
-        } else {
-            // Positional arguments
-            $a = @$arguments[0];
-            $b = @$arguments[1];
-        }
-
-        return self::sub($a, $b);
-    }
-
     /**
-     * Returns the value $a - $b
+     * Returns the value $a + $b.
      *
      * @param mixed $a
      * @param mixed $b
      *
      * @return int|null
-     * Returns $a - $b if both $a and $b are integers
-     * Returns null otherwise
+     * Returns $a + $b if both $a and $b are integers.
+     * Returns null otherwise.
      */
-    private static function sub($a, $b)
+    public static function add($a, $b)
     {
-        if (!is_int($a) || !is_int($b)) {
-            return null;
+        if (is_int($a) && is_int($b)) {
+            return $a + $b;
         }
 
-        return $a - $b;
+        return null;
     }
 }

examples/client.php

@@ -6,8 +6,9 @@
 
 $client = new Client();
 
-$client->query(1, 'Math/subtract', array(5, 3));
+$client->query(1, 'add', array(1, 2));
 
 $request = $client->encode();
 
-echo $request, "\n"; // {"jsonrpc":"2.0","id":1,"method":"Math\/subtract","params":[5,3]}
+echo $request, "\n";
+// {"jsonrpc":"2.0","id":1,"method":"add","params":[1,2]}

examples/server.php

@@ -2,14 +2,16 @@
 
 require_once __DIR__ . '/../vendor/autoload.php';
 
-use Datto\JsonRpc\Tests\Example\Stateless\Translator;
 use Datto\JsonRpc\Server;
 
-$translator = new Translator();
-$server = new Server($translator);
+$interpreter = function ($method) {
+    // Convert a JSON-RPC string method name into an actual callable method
+    return array('\\Datto\\JsonRpc\\Examples\\Application\\Math', $method);
+};
 
-$request = '{"jsonrpc":"2.0","id":1,"method":"Math\/subtract","params":[5,3]}';
+$server = new Server($interpreter);
 
-$reply = $server->reply($request);
+$reply = $server->reply('{"jsonrpc":"2.0","id":1,"method":"add","params":[1,2]}');
 
-echo $reply, "\n"; // {"jsonrpc":"2.0","id":1,"result":2}
+echo $reply, "\n";
+// {"jsonrpc":"2.0","id":1,"result":3}

src/Server.php

@@ -35,15 +35,15 @@ class Server
 {
     const VERSION = '2.0';
 
-    /** @var Translator */
-    private $translator;
+    /** @var callable */
+    private $interpreter;
 
     /**
-     * @param Translator $translator
+     * @param callable $interpreter
      */
-    public function __construct(Translator $translator)
+    public function __construct(callable $interpreter)
     {
-        $this->translator = $translator;
+        $this->interpreter = $interpreter;
     }
 
     /**
@@ -208,7 +208,7 @@ private function processRequest($request)
      */
     private function processQuery($id, $method, $arguments)
     {
-        $callable = $this->translator->getCallable($method);
+        $callable = $this->getCallable($method);
 
         if (!is_callable($callable)) {
             return self::errorMethod($id);
@@ -228,20 +228,36 @@ private function processQuery($id, $method, $arguments)
      * Processes a notification. No response is necessary.
      *
      * @param string $method
-     * String value representing a method to invoke on the server
+     * String value representing a method to invoke on the server.
      *
      * @param array $arguments
      * Array of arguments that will be passed to the method.
      */
     private function processNotification($method, $arguments)
     {
-        $callable = $this->translator->getCallable($method);
+        $callable = $this->getCallable($method);
 
         if (is_callable($callable)) {
             self::run($callable, $arguments);
         }
     }
 
+    /**
+     * Converts a string method name to an actual callable, by asking
+     * the interpreter to translate.
+     *
+     * @param string $method
+     * String value representing the method to invoke on the server.
+     *
+     * @return callable|null
+     * Returns the callable that corresponds to the string name.
+     * Returns null if there is no equivalent callable.
+     */
+    private function getCallable($method)
+    {
+        return call_user_func($this->interpreter, $method);
+    }
+
     /**
      * Executes a callable with the supplied arguments, and returns the result.
      *

tests/ClientTest.php

@@ -33,7 +33,7 @@ public function testNotification()
         $client = new Client();
         $client->notify('subtract', array(3, 2));
 
-        $this->compare($client,    '{"jsonrpc":"2.0","method":"subtract","params":[3,2]}');
+        $this->compare($client, '{"jsonrpc":"2.0","method":"subtract","params":[3,2]}');
     }
 
     public function testQuery()