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)


In this chapter, we briefly discussed the pros and cons of the microservice-based approach.

We've built two small examples with similar functionality but different technological stacks.

The first project was built using a purely functional approach with wrapping effects in IO monad and functional streams. This allowed us to describe a system as a computation that is only started at the end of the world. We used the ORM approach in this case by mapping the state of the system to the database table and modifying it in response to the required changes. Finally, we demonstrated how to use the http4s client to test the system as a whole by building an integration test.

The basis for the second project was the "official" Lightbend stack. We looked at how well Akka-HTTP and Akka Persistence play together. We demonstrated that the event-sourced approach allows us...