Rename and move Promise

lib/Deferred.php

@@ -39,7 +39,7 @@ try {
             private $fail;
 
             public function __construct() {
-                $this->awaitable = new Promise(function (callable $resolve, callable $fail) {
+                $this->awaitable = new Internal\PrivateAwaitable(function (callable $resolve, callable $fail) {
                     $this->resolve = $resolve;
                     $this->fail = $fail;
                 });

lib/Internal/PrivateAwaitable.php

@@ -1,33 +1,30 @@
 <?php
 
-namespace Amp\Awaitable;
+namespace Amp\Awaitable\Internal;
 
 use Interop\Async\Awaitable;
 
 /**
- * A Promise is an awaitable that provides the functions to resolve or fail the promise to the resolver function
- * given to the constructor. A Promise cannot be externally resolved. Only the functions provided to the constructor
- * may resolve the Promise.
+ * An awaitable that cannot be externally resolved. Used by Deferred in development mode.
  */
-final class Promise implements Awaitable {
-    use Internal\Placeholder;
+final class PrivateAwaitable implements Awaitable {
+    use Placeholder;
 
     /**
      * @param callable(callable $resolve, callable $reject): void $resolver
      */
     public function __construct(callable $resolver) {
         /**
-         * Resolves the promise with the given promise or value. If another promise, this promise takes
-         * on the state of that promise. If a value, the promise will be fulfilled with that value.
+         * Resolves the awaitable with the given awaitable or value.
          *
-         * @param mixed $value A promise can be resolved with anything other than itself.
+         * @param mixed $value
          */
         $resolve = function ($value = null) {
             $this->resolve($value);
         };
         
         /**
-         * Fails the promise with the given exception.
+         * Fails the awaitable with the given exception.
          *
          * @param \Exception $reason
          */

lib/functions.php

@@ -201,9 +201,11 @@ function adapt($thenable) {
         return new Failure(new \InvalidArgumentException("Must provide an object with a then() method"));
     }
 
-    return new Promise(function (callable $resolve, callable $fail) use ($thenable) {
-        $thenable->then($resolve, $fail);
-    });
+    $deferred = new Deferred;
+
+    $thenable->then([$deferred, 'resolve'], [$deferred, 'fail']);
+
+    return $deferred->getAwaitable();
 }
 
 /**