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

Summary

You should now have a better understanding of functional programming and its benefits, as well as how Kotlin approaches this topic. We've discussed the concepts of immutability and pure functions, and how combining these results in more testable code that is easier to maintain.

We discussed how Kotlin supports closures, which allow a function to access the variables of the function that wraps it and effectively store the state between executions. This enables techniques such as currying and memoization that allow us to fix some of the function arguments (by acting as defaults) and remember the value returned from a function in order to avoid recalculating it.

We learned that Kotlin uses the tailrec keyword to allow the compiler to optimize tail recursion. We also looked at higher-order functions, expressions versus statements, and pattern matching. All of these concepts allow us to write code that is easier to test and has less risk of concurrency bugs.

In...