@@ -853,7 +853,7 @@ function bind (object, method) {
853853* ES5 has bind builtin, it also accepts partial argument list
854854
855855```js
856- //basic implementation handling partial application
856+ //basic example implementation handling partial application
857857Function.prototype.bind = Function.prototype.bind || function(thisArg) {
858858 var fn = this;
859859 var slice = Array.prototype.slice;
@@ -863,4 +863,37 @@ Function.prototype.bind = Function.prototype.bind || function(thisArg) {
863863 return fn.call(thisArg, args.concat(slice.call(arguments)))
864864 }
865865}
866- ````
866+ ```
867+ ## 7. Design patterns
868+
869+ * as made famous by the GoF book
870+ * language independent but mainly for Java/C++ like strongly typed languages
871+ * most of them are really easy to implement in JavaScript
872+
873+ ### singleton
874+
875+ * only one instance of specific class
876+ * JS: no classes, when you create a new object there's no other like it
877+ * (in JS some people mean Chapter 5. module pattern by singletons)
878+ * you might want singletons when using ```new```:
879+ * store instance as a (static) property on constructor function
880+ * but static property is public
881+ * can also protect instance as a private static member (via closure)
882+ * (be careful not to wipe out prototype properties)
883+
884+ ```js
885+ var IAmSingleton;
886+
887+ (function(){
888+ var instance;
889+ IAmSingleton = function() {
890+ if (instance) {
891+ return instance;
892+ }
893+ instance = this;
894+
895+ //... all the functionality
896+ this.whatever = true;
897+ }
898+ })();
899+ ```
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