Book Image

Learn Scala Programming

By : Slava Schmidt
Book Image

Learn Scala Programming

By: Slava Schmidt

Overview of this book

The second version of Scala has undergone multiple changes to support features and library implementations. Scala 2.13, with its main focus on modularizing the standard library and simplifying collections, brings with it a host of updates. Learn Scala Programming addresses both technical and architectural changes to the redesigned standard library and collections, along with covering in-depth type systems and first-level support for functions. You will discover how to leverage implicits as a primary mechanism for building type classes and look at different ways to test Scala code. You will also learn about abstract building blocks used in functional programming, giving you sufficient understanding to pick and use any existing functional programming library out there. In the concluding chapters, you will explore reactive programming by covering the Akka framework and reactive streams. By the end of this book, you will have built microservices and learned to implement them with the Scala and Lagom framework.
Table of Contents (19 chapters)

Object-oriented aspects of functions

We mentioned that Scala is a fusion of object-oriented and functional paradigms. Because of this, Scala has functions as a first-class element of the language. Also because of this, everything is an object in Scala. This is partly related to the fact that everything is an object or a primitive type in the JVM, but Scala goes further and also hides primitives behind objects.

It turns out that functions are also objects! Depending on the number of arguments, they extend one of the special traits. Also because of their object-oriented nature, it is possible to implement additional features by defining additional methods on the implementing class. This is how partial function is implemented. It is also natural to utilize companion objects to define common logic for functions so that it can be easily reused. It's even possible to write some...