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)

Ways to define a function

To provide some common ground for the readers with different levels of Scala knowledge, let's recap how a function can be defined. We'll start with the basic approaches such as defining a method and placing it in different scopes to create a local function. Then we'll look at more interesting aspects, for example closing over scope, partial application, different ways to specify function literals, and, finally, currying.

Function as a method

Most Scala developers came to it from Java. Because of this, probably the most common way is to define a method inside of a class, trait, or an object, like in the following familiar example:

class MethodDefinition {
def eq(arg1: String, arg2:...