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

Type-classes


Why would someone need a concept such as a type-class? To answer this, we'll first have to understand what a type-class exactly is. As they say, "Type-classes allow us to generalize over a set of types in order to define and execute a standard set of features for those types." Let's try to understand this.

I believe you're aware of the notion of encoding and decoding. Let's think of encoding as applying a certain rule to convert A into a specific pattern. Now, after you encode something, it's in that specific pattern. Decoding is the exact opposite of what we just did: it's changing your type A from the pattern we just created to its original shape. For example, comma-separated values (CSV) can be considered an encoded pattern. Hence, there's a scheme that converts words from a source to CSV format:

trait CSVEncoder[T] { 
  def encode(t: T): List[String] 
} 

We've written a trait named CSVEncoder[T]. It's time to rephrase what we said for type-classes. CSVEncoder allows us to generalize...