# Design patterns in golang >A beginner guide... happy coding! ## Table of Contents - [Creational patterns](#creational-patterns) - [Singleton](#singleton) - [Builder](#builder) - [Factory](#factory) - [Abstract Factory](#abstract-factory) - [Prototype](#prototype) - [Structural patterns](#structural-patterns) - [Composition](#composition) - [Adapter](#adapter) - [Bridge](#bridge) - [Behavioral patterns](#behavioral-patterns) - [Chain of responsibility](#chain-of-responsibility) - [Strategy](#strategy) - [Observer](#observer) - [State](#state) - [Visitor](#visitor) - [Mediator](#mediator) - [Template](#template) - [Memento](#memento) - [Interpretor](#interpretor) - [Command](#command) - [Concurrency patterns](#concurrency-patterns) --- ## Creational patterns Creational design patterns abstract the instantiation process. They help make a system independent of how its objects are created, composed, and represented. ### Singleton Ensure a class only has one instance, and provide a global point of access to it. ### Builder Separate the construction of a complex object from its representation so that the same construction process can create different representations. ### Factory Define an interface for creating an object, but let subclasses decide which class to instantiate. Factory Method lets a class defer instantiation to subclasses. ### Abstract Factory Provide an interface for creating famili es of related or dependent objects without specifying their concrete classes. ### Prototype Specify the kinds of objects to create using a prototypical instance, and create new objects by copying this protoype. ## Structural patterns Structural patterns are concerned with how classes and objects are composed to form larger structures. Structural class patterns use inheritance to compose interfaces or implementations. As a simple example, consider how multiple inheritance mixes two or more classes into one. ### Composition Compose objects into tree structures to represent part-whole hierarchies. Composite lets clients treat individual objects and compositions of objects uniformly. ### Adapter Convert the interfac e 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 its implementation so that the two can vary independently. ## Behavioral patterns Behavioral patterns are concerned with algorithms and the assignment of responsibilities between objects. Behavio ral patterns describe not just patterns of objects or classes but also the patterns of communication between them. These patterns characterize complex control flow that's difficult to follow at run-time. They shift your focus away from flow of control to let you concent ratejust on the way objects are interconnected. ### Chain of responsibility 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. ### Strategy Define a family oafl gorit h ms, encapsulate each one, and make them interchangeable. Strategy lets the algorithm vary independently from clients that use it. ### Observer Define a one-to-many dependency between objects so that when one object changes state, all its dependents are notified and updated automatically ### State Allow an object alter its behavior when its internal state changes. The object will appear on change its class ### Visitor Represent an operation to be performed on the elements of an object structure.Visitor lets you define new operation without changing the classes of the elements of which operates ### 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 ### Template 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 structure. ### Memento Without violating encapsulation, capture and externalize an object's internal state so that the object can be restored to this state later. ### Interpretor Given a language, define a representation for its grammar along with an interpreter that uses the representation to interpret sentences in the language. ### Command Encapsulate a request as an object, thereby letting you parametrize clients with different requests, and support undoable operations. ## Concurrency patterns Pattenrs for concurrent work and parallel execution in Go.