Book Image

Kotlin Design Patterns and Best Practices - Second Edition

By : Alexey Soshin
Book Image

Kotlin Design Patterns and Best Practices - Second Edition

By: Alexey Soshin

Overview of this book

This book shows you how easy it can be to implement traditional design patterns in the modern multi-paradigm Kotlin programming language, and takes you through the new patterns and paradigms that have emerged. This second edition is updated to cover the changes introduced from Kotlin 1.2 up to 1.5 and focuses more on the idiomatic usage of coroutines, which have become a stable language feature. You'll begin by learning about the practical aspects of smarter coding in Kotlin, as well as understanding basic Kotlin syntax and the impact of design patterns on your code. The book also provides an in-depth explanation of the classical design patterns, such as Creational, Structural, and Behavioral families, before moving on to functional programming. You'll go through reactive and concurrent patterns, and finally, get to grips with coroutines and structured concurrency to write performant, extensible, and maintainable code. By the end of this Kotlin book, you'll have explored the latest trends in architecture and design patterns for microservices. You’ll also understand the tradeoffs when choosing between different architectures and make informed decisions.
Table of Contents (17 chapters)
1
Section 1: Classical Patterns
6
Section 2: Reactive and Concurrent Patterns
11
Section 3: Practical Application of Design Patterns

Composite

This chapter is dedicated to composing objects within one another, so it may look strange to have a separate section for the Composite design pattern. As a result, this raises a question:

Shouldn't this design pattern encompass all of the others?

As in the case of the Bridge design pattern, the name may not reflect its true uses and benefits.

Let's continue with our StormTrooper example from before. Lieutenants of the Empire quickly discover that no matter how well equipped, stormtroopers cannot hold their ground against the rebels because they are uncoordinated.

To provide better coordination, the Empire decides to introduce the concept of a squad for the stormtroopers. A squad should contain one or more stormtrooper of any kind, and when given commands, it should behave exactly as if it was a single unit.

Squad, clearly, consists of a collection of stormtroopers:

class Squad(val units: List<Trooper>)

Let's add a couple of them to...