Reduce number of array

lib/rsvp/queue.js

@@ -12,39 +12,30 @@ function ResolvedQueueError(message) {
 ResolvedQueueError.prototype = new Error();
 ResolvedQueueError.prototype.constructor = ResolvedQueueError;
 
-var last_promise,
-  i;
-
 var Queue = function() {
   if (!(this instanceof Queue)) {
     return new Queue();
   }
 
-  var queue = this,
-    promise_stack = [],
-    then_stack = [];
+  var promise_stack = [],
+    // handleQueue
+    detect_end_index = 1;
 
-  Promise.call(queue, function (resolveQueue, rejectQueue) {
+  Promise.call(this, function (resolveQueue, rejectQueue) {
     var detectQueueSuccess,
       detectQueueError;
 
     function handleQueue() {
-      if (then_stack.length === 0) {
+      if (promise_stack.length === detect_end_index) {
         return true;
       }
-
-      last_promise = promise_stack[promise_stack.length - 1];
-      promise_stack.splice(0, promise_stack.length);
-      for (i = then_stack.length - 1; i >= 0; i -= 2) {
-        last_promise = last_promise.then(then_stack[i - 1], then_stack[i]);
-        promise_stack.push(last_promise);
-      }
-      then_stack.splice(0, then_stack.length);
+      promise_stack.splice(0, detect_end_index);
 
       promise_stack.push(
-        last_promise.then(detectQueueSuccess,
+        promise_stack[promise_stack.length - 1].then(detectQueueSuccess,
                                                      detectQueueError)
       );
+      detect_end_index = promise_stack.length;
       return false;
     }
 
@@ -64,28 +55,29 @@ var Queue = function() {
 
     // Resolve by default
     promise_stack.push(
-      resolve().then(detectQueueSuccess, detectQueueError)
+      resolve().then(detectQueueSuccess)
     );
 
   }, function () {
     // Cancel all created promises
     var i;
-    then_stack.splice(0, then_stack.length);
     for (i = 0; i < promise_stack.length; i += 1) {
       promise_stack[i].cancel();
     }
 
   });
 
-  queue.push = function (done, fail) {
-    if (queue.isFulfilled || queue.isRejected) {
+  this.push = function (done, fail) {
+    if (this.isFulfilled || this.isRejected) {
       throw new ResolvedQueueError();
     }
-    then_stack.unshift(done, fail);
-    return queue;
+    promise_stack.push(
+      promise_stack[promise_stack.length - 1].then(done, fail)
+    );
+    return this;
   };
 
-  return queue;
+  return this;
 };
 
 Queue.prototype = Object.create(Promise.prototype);