Summary
This was a long chapter and we covered a lot of topics. We started this chapter with a brief introduction to functional programming, looked at why it is useful, and reviewed examples of RT. We then looked at various language features and constructs, starting with classes, objects, and traits. We looked at HOFs, which are one of the fundamental building blocks of functional programming. We looked at polymorphic functions and saw how they enable us to write reusable code. Then, we looked at variance, which defines subtyping relationships between objects, took a detailed tour of pattern matching, and finally, ended with implicit conversion, which is a powerful language feature used in design patterns such as type classes.
In the next chapter, we are going to focus on setting up the environment, which will allow you to follow along with the rest of the chapters.
