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)


The definition of the abelian group concludes our discussion of abstract algebraic structures; that is, the structures solely defined by the laws they satisfy.

We looked at three such structures: semigroup, monoid, and group. The semigroup is defined by a binary operation that is closed and associative. The monoid adds to this an identity element so that the operation applied to it and another argument returns the second argument unchanged. The group extends monoids with an invertibility law, stating that for each element there should be another element so that the operation applied on them returns an identity element. If the operation defined by the group is commutative, the group is called abelian.

We provided an example implementation for all these algebraic equations, along with ScalaCheck properties for verifying that our implementations are sane.

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