Domain Modeling Made Functional

Chapter 8Understanding Functions

In the preceding parts of the book, we have captured the requirements for an order-placing workflow and then modeled it using types. The next task is to implement that design using a functional programming (FP) approach.

But before we get to that, let’s make sure that we understand what functional programming is and what tools and tactics we’ll need in order to create the implementation. By the end of this chapter, you should have a good grasp of the key concepts in FP, which are valuable for doing any kind of programming, not just domain-driven design.

This book cannot possibly explain everything about functional programming, so we’ll just focus on the basics. We’ll look at what functions are and how to do function ...