Book Image

Hands-On Design Patterns with Kotlin

By : Alexey Soshin
Book Image

Hands-On Design Patterns with Kotlin

By: Alexey Soshin

Overview of this book

Design patterns enable you as a developer to speed up the development process by providing you with proven development paradigms. Reusing design patterns helps prevent complex issues that can cause major problems, improves your code base, promotes code reuse, and makes an architecture more robust. The mission of this book is to ease the adoption of design patterns in Kotlin and provide good practices for programmers. The book begins by showing you the practical aspects of smarter coding in Kotlin, explaining the basic Kotlin syntax and the impact of design patterns. From there, the book provides an in-depth explanation of the classical design patterns of creational, structural, and behavioral families, before heading into functional programming. It then takes you through reactive and concurrent patterns, teaching you about using streams, threads, and coroutines to write better code along the way By the end of the book, you will be able to efficiently address common problems faced while developing applications and be comfortable working on scalable and maintainable projects of any size.
Table of Contents (13 chapters)

Active Object

This design pattern allows a method to be executed in a safe way on another thread. Guess what else is being executed on another thread?

You're totally right: actor().

So, it's one of those design patterns that is already built into the language. Or, to be precise, into one of the accommodating libraries.

We've already seen how to send data to actor(). But how do we receive data from it?

One way is to supply it with a channel for output:

fun activeActor(out: SendChannel<String>) = actor<Int> {
for (i in this) {
out.send(i.toString().reversed())
}
out.close()
}

Remember to close the output channel when you're done.

Testing

To test the Active Object pattern, we&apos...