Book Image

Learning Scala Programming

By : Vikash Sharma
Book Image

Learning Scala Programming

By: Vikash Sharma

Overview of this book

Scala is a general-purpose programming language that supports both functional and object-oriented programming paradigms. Due to its concise design and versatility, Scala's applications have been extended to a wide variety of fields such as data science and cluster computing. You will learn to write highly scalable, concurrent, and testable programs to meet everyday software requirements. We will begin by understanding the language basics, syntax, core data types, literals, variables, and more. From here you will be introduced to data structures with Scala and you will learn to work with higher-order functions. Scala's powerful collections framework will help you get the best out of immutable data structures and utilize them effectively. You will then be introduced to concepts such as pattern matching, case classes, and functional programming features. From here, you will learn to work with Scala's object-oriented features. Going forward, you will learn about asynchronous and reactive programming with Scala, where you will be introduced to the Akka framework. Finally, you will learn the interoperability of Scala and Java. After reading this book, you'll be well versed with this language and its features, and you will be able to write scalable, concurrent, and reactive programs in Scala.
Table of Contents (21 chapters)
Title Page
Packt Upsell
Contributors
Preface
Index

Reactive extensions


All these APIs serve the same purpose, that is, to provide asynchronous Observable streams in their respective platforms. These APIs revolve around the principle of events and streams. Let's check out what these reactive extensions provide. It's time to see the term we just introduced ourselves to, that is, Observables.

Observables are the entities that emit a stream of events. Events can be a button click or checking a checkbox, or some other event like providing input to some device via the interface exposed. There has to be an observer that reacts to whatever value or sequence of values the Observable is emitting. The way observers react to events is by subscribing to the Observable. So these observers subscribing to Observables to react to events is the main theme of ReactiveX. The process in any of the libraries available for different platforms is somewhat similar to the following:

  • We define the Observable, which does the job of emitting events. This will be in an...