added parallel and series methods

1 files changed, 30 insertions, 0 deletions

diff --git a/lib/async.js b/lib/async.js
index 3634bf2..faac869 100644
--- a/lib/async.js
+++ b/lib/async.js
@@ -63,3 +63,33 @@ exports.waterfall = function(arr){
     };
     makeCallback(0)();
 };
+
+exports.parallel = function(arr, callback){
+    var results = [];
+    arr.forEach(function(fn){
+        fn(function(){
+            var args = Array.prototype.slice.call(arguments);
+            results.push((args.length > 1) ? args: args[0]);
+            if(results.length == arr.length){
+                callback(results);
+            }
+        });
+    });
+};
+
+exports.series = function(arr, callback){
+    var results = [];
+    var makeCallback = function(index){
+        return function(){
+            if(index > 0){
+                var args = Array.prototype.slice.call(arguments);
+                results.push((args.length > 1) ? args: args[0]);
+            }
+            if(index < arr.length){
+                arr[index](makeCallback(index+1));
+            }
+            else callback(results);
+        }
+    };
+    makeCallback(0)();
+};