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

Understanding the Actor system


Akka documentation simply explains an ActorSystem as a heavyweight structure that will allocate 1 to N threads, and we should create one per logical application. Once we create an actor system, we get the license to create actors under that system. We'll take a look at how we can create Actors in the next sections.

When we create actors as part of a system, these actors share the same configuration (such as dispatchers, paths, and addresses) as the Actor system.

Within an Actor system, there's a root guardian Actor; this serves as a parent actor to all actors residing within an actor system, internal actors, as well actors that we create. So, as expected, this is the last actor to be stopped when the system terminates.

The reason why Akka provides these guardian actors is to supervise the first-level actors we create, so for user created actors too, we have a specific user guardian. Similarly, for system provided actors, Akka has system guardian.

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