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

Visitor

This design pattern is usually a close friend of the Composite design pattern, which we discussed in Chapter 3, Understanding Structural Patterns. It can either extract data from a complex tree-like structure or add behavior to each node of the tree, much like the Decorator design pattern does for a single object.

My plan, being a lazy software architect, worked out quite well. My request-answering system from the chain of responsibility worked quite well and I don't have plenty of time for coffee. But I'm afraid some developers begin to suspect that I'm a bit of a fraud.

To confuse them, I plan to produce weekly emails with links to all the latest buzzword articles. Of course, I don't plan to read them myself – I just want to collect them from some popular technology sites.

Writing a crawler

Let's look at the following data structure, which is very similar to what we had when we discussed the Iterator design pattern:

Page(Container...