This is a simple implementation of the 23 Design Patterns identified by GoF
Design patterns are solutions to software design problems that solves real-world problems in application development. They are about reuse designs of objects.
The 23 Gang of Four (GoF) patterns became very popular when the book Design Patterns: Elements of Reusable Object-Oriented Software was released back in 1995. There are three categories or groups or families: Creational, Structural and Behavioral.
Abstract Factory: Provide an interfacefor creating families ofrelated or dependent objects without specifying their concrete classes. (not implemented yet)
Builder: Separate the construction of a complex object from its representation so that the same construction process can create different representations. (not implemented yet)
Factory Method: Define an interface for creating an object,but let subclasses decide which class to instantiate. Factory Method lets a class defer instantiation to subclasses.
Prototype: Specify the kinds of objectsto create using a prototypical instance, and create new objects by copying this prototype (not implemented yet)
Singleton: Ensure a class only has one instance, and provide a global point of access to it.
Adapter: Convert the interface of a class into another interface clients expect. Adapter lets classes work together that couldn't otherwise because of incompatible interfaces.
Bridge: Decouple an abstraction from itsimplementation so that the two canvary independently. (not implemented yet)
Composite: Compose objectsinto tree structures to represent part-whole hierarchies. Composite lets clients treat individual objects and compositions of objects uniformly. (not implemented yet)
Decorator: Attachadditional responsibilities to an object dynamically.Decorators provide a flexible alternative to subclassing for extending functionality
Facade: Provide a unified interface to a set of interfacesin a subsystem. Facade defines a higher-level interface that makesthe subsystem easier to use.
Flyweight: Use sharing to support large numbers of fine-grained objects efficiently. (not implemented yet)
Proxy: Provide a surrogate or placeholder for another object to control access to it. (not implemented yet)
Chain of Responsability: Avoid coupling the sender of a request to its receiver by giving more than one object a chance to handle the request. Chain the receiving objects and pass the request along the chain until an object handles it
Command: Encapsulate a request as an object, thereby letting you parameterize clients with different requests, queue or log requests, and support undoable operations.
Interpreter: Given a language, define a represention for its grammar along with an interpreter that uses the representation to interpret sentences in the language (not implemented yet)
Iterator: Provide a way to accessthe elements of an aggregate objectsequentially without exposing its underlying representation. (not implemented yet)
Mediator: Define an object that encapsulates how a set of objects interact. Mediator promotes loose coupling by keeping objects from referring to each other explicitly, and it lets you vary their interaction independently
Memento: Without violating encapsulation, capture and externalize an object's internal state so that the object can be restored to this state later (not implemented yet)
Observer: Define a one-to-many dependency between objectsso that when one object changes state, all its dependents are notified and updated automatically. (not implemented yet)
State: Allow an object to alter its behavior when its internal state changes. The object will appear to change its class. (not implemented yet)
Strategy: Define a family of algorithms, encapsulate each one, and make them interchangeable. Strategy lets the algorithm vary independently from clients that use it. (not implemented yet)
Template Method: Define the skeleton of an algorithm in an operation, deferring some steps to subclasses. Template Method lets subclasses redefine certain steps of an algorithm without changing the algorithm's structure.
Visitor: Represent an operation to be performed on the elements of an object structure. Visitorlets you define a new operation without changing the classesof the elements on which it operates. (not implemented yet)