Put the split to get the list of promise methods out of the promise method...

Put the split to get the list of promise methods out of the promise method itself and also switched from jQuery.each to a while loop to remove as much overhead as possible. Thanks go to scott_gonzalez for reminding me of this.

src/core.js

@@ -63,6 +63,9 @@ var jQuery = function( selector, context ) {
 	// The deferred used on DOM ready
 	readyList,
 
+	// Promise methods
+	promiseMethods = "then done fail isResolved isRejected promise".split( " " ),
+
 	// The ready event handler
 	DOMContentLoaded,
 
@@ -914,16 +917,18 @@ jQuery.extend({
 			isRejected: failDeferred.isResolved,
 			// Get a promise for this deferred
 			// If obj is provided, the promise aspect is added to the object
-			promise: function( obj ) {
+			// (i is used internally)
+			promise: function( obj , i ) {
 				if ( obj == null ) {
 					if ( promise ) {
 						return promise;
 					}
 					promise = obj = {};
 				}
-				jQuery.each( "then done fail isResolved isRejected promise".split( " " ) , function( _ , method ) {
-					obj[ method ] = deferred[ method ];
-				});
+				i = promiseMethods.length;
+				while( i-- ) {
+					obj[ promiseMethods[ i ] ] = deferred[ promiseMethods[ i ] ];
+				}
 				return obj;
 			}