Generalize bind to sequences of arbitrary length and add an apply method to get the result of an application into the async monad

src/async.js

@@ -1,5 +1,6 @@
 function Async() {
 	return {
+		apply: apply,
 		bind: bind,
 		parallel: parallel,
 		run: run,
@@ -8,12 +9,30 @@ function Async() {
 		wrap: wrap
 	};
 
-	function bind(m, f) {
+	function apply(f, x) {
 		return function(g) {
-			m(function(x) {
-				f(x)(g);
-			});
+			g(f(x));
+		};
+	}
+
+	function bind() {
+		var m, steps, i;
+		if(arguments.length < 1) {
+			return wrap();
 		}
+		m = arguments[0];
+		steps = arguments;
+		i = 1;
+		return function(f) {
+			var step = function(x) {
+				if(i < steps.length) {
+					steps[i++](x)(step);
+				} else {
+					return f(x);
+				}
+			}
+			m(step);
+		};
 	}
 
 	function parallel() {