Book Image

Scala Design Patterns

By : Ivan Nikolov
Book Image

Scala Design Patterns

By: Ivan Nikolov

Overview of this book

Scala has become increasingly popular in many different IT sectors. The language is exceptionally feature-rich which helps developers write less code and get faster results. Design patterns make developer’s lives easier by helping them write great software that is easy to maintain, runs efficiently and is valuable to the company or people concerned. You will learn about the various features of Scala and be able to apply well-known, industry-proven design patterns in your work. The book starts off by focusing on some of the most interesting features of Scala while using practical real-world examples. We will also cover the popular "Gang of Four" design patterns and show you how to incorporate functional patterns effectively. By the end of this book, you will have enough knowledge and understanding to quickly assess problems and come up with elegant solutions.
Table of Contents (20 chapters)
Scala Design Patterns
Credits
About the Author
Acknowledgments
About the Reviewer
www.PacktPub.com
Preface
Index

Mixin compositions


Scala allows developers to extend many traits in a single class. This adds the possibility of achieving multiple inheritance and save a lot of efforts in code writing, which has to be performed in languages where extending many classes is not allowed. In this sub topic, we will show how traits can be mixed in a specific class or used to create anonymous classes with some specific functionality while writing our code.

Mixing traits in

First of all, let's modify the code from the last example. It is a really simple change and it will also show exactly how traits can be mixed in:

object MixinRunner extends Ping with Pong { 
  def main(args: Array[String]): Unit = { 
    ping() 
    pong() 
  } 
}

As it can be seen from the preceding code, we can add multiple traits to a class. We've used object in the example just because of the main method. This would be similar to creating a class with no constructor parameters.

Tip

How to mix traits in?

Mixing traits into a class is done with...