Book Image

Scala Functional Programming Patterns

By : Atul S. Khot
Book Image

Scala Functional Programming Patterns

By: Atul S. Khot

Overview of this book

Scala is used to construct elegant class hierarchies for maximum code reuse and extensibility and to implement their behavior using higher-order functions. Its functional programming (FP) features are a boon to help you design “easy to reason about” systems to control the growing software complexities. Knowing how and where to apply the many Scala techniques is challenging. Looking at Scala best practices in the context of what you already know helps you grasp these concepts quickly, and helps you see where and why to use them. This book begins with the rationale behind patterns to help you understand where and why each pattern is applied. You will discover what tail recursion brings to your table and will get an understanding of how to create solutions without mutations. We then explain the concept of memorization and infinite sequences for on-demand computation. Further, the book takes you through Scala’s stackable traits and dependency injection, a popular technique to produce loosely-coupled software systems. You will also explore how to currying favors to your code and how to simplify it by de-construction via pattern matching. We also show you how to do pipeline transformations using higher order functions such as the pipes and filters pattern. Then we guide you through the increasing importance of concurrent programming and the pitfalls of traditional code concurrency. Lastly, the book takes a paradigm shift to show you the different techniques that functional programming brings to your plate. This book is an invaluable source to help you understand and perform functional programming and solve common programming problems using Scala’s programming patterns.
Table of Contents (19 chapters)
Scala Functional Programming Patterns
About the Author
About the Reviewers


We had a pretty detailed look at Java interfaces and got to know that interfaces are contracts. When a class implements the contract, we can reuse the existing code. The iterator pattern is an example of such a contract. By following the interface iterable's contract, we were able to reuse the Java code for each loop with our own custom class.

When a language supports multiple inheritances, the method resolution might get ambiguous. Java does not support multiple inheritance, hence, we don't see this problem.

Scala traits resolve many of these problems. We can put in reusable code in traits and then mix-in traits into our classes or objects as needed. We looked at how mix-ins enable rich interfaces. Traits are stackable and allow us to change the existing object methods, namely stackable modifications.

Dependencies injection is a very popular pattern. The general theme behind it is inversion of control. Scala traits allow us to come up with their own dependencies injection and the cake...