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)

Generators

We have had a detailed discussion of properties, but haven't mentioned yet where the input data for these properties comes from. Let's correct this omission and give generators the care they deserve.

The idea of the generator comes from the general concept of types. In a sense, a type is a specification of possible values complying to that type. In other words, types describe the rules that values must comply to. These rules give us the possibility to generate ranges of data values for given types.

For some types there are more values; for others, there are less. As we already know, there are literal types which contain a single value. The same applies for Unit type with its () value. For Boolean, there are two values that exist: true and false. Two values would also exist for an imaginary equality relation type—equal and non-equal. With the same principle...