add Abstract Factory

README.md

@@ -3,18 +3,17 @@
 Software design patterns are general reusable solutions to problems which occur
 over and over again in object-oriented design enviroment. It is not a finished 
 design that can be transformed into source code directly, but it is template how
-to solve the problem. Templates in this repository are based mainly on book 
-[Design Patterns by The "Gang of Four"]. We can classify them by purpose
-into creational (abstract the instantiation process), structure (how classes and 
-objects are composed to form larger structures) and behavioral patterns (the 
-assignment of responsibilities between objects).  
+to solve the problem. We can classify them by purpose into creational (abstract 
+the instantiation process), structure (how classes and objects are composed to form 
+larger structures) and behavioral patterns (the assignment of responsibilities between 
+objects).  
 
 - Creational Patterns 
  - [Abstract Factory], families of product objects
- - [Builder], todo
- - [Factory Method], todo
- - [Prototype], todo
- - [Singleton], todo 
+ - [Builder], how a composite object gets created
+ - [Factory Method], subclass of object that is instantiated
+ - [Prototype], class of object that is instantiated
+ - [Singleton], the sole instance of a class 
 - Structural Patterns
  - [Adapter], todo
  - [Bridge], todo 
@@ -43,10 +42,21 @@ In my repository you can find implementation of desgin patterns also in language
 * [Design Patterns in Java]
 * [Design Patterns in Python]
 
+### References
+Design patterns in this repository are based on
+
+* [Design Patterns by The "Gang of Four"]
+* [Head First: Design Patterns]
+* [Wikipedia]
+
 [Design Patterns in C++]: https://github.com/JakubVojvoda/design-patterns-cpp
 [Design Patterns in Java]: https://github.com/JakubVojvoda/design-patterns-java
 [Design Patterns in Python]: https://github.com/JakubVojvoda/design-patterns-python
+
 [Design Patterns by The "Gang of Four"]: https://en.wikipedia.org/wiki/Design_Patterns
+[Head First: Design Patterns]: http://www.headfirstlabs.com/books/hfdp/ 
+[Wikipedia]: https://en.wikipedia.org/wiki/Software_design_pattern
+
 [Abstract Factory]: https://github.com/JakubVojvoda/design-patterns-cpp/tree/master/abstract-factory
 [Builder]: https://github.com/JakubVojvoda/design-patterns-cpp/tree/master/builder
 [Factory Method]: https://github.com/JakubVojvoda/design-patterns-cpp/tree/master/factory-method