A big part of programming is abstraction. We find common functionality, laws, and behavior and encapsulate them into classes, interfaces, functions, and so on, which are abstract and allow code reuse. Then, we refer to them and reuse them to minimize code duplication and the possibility of errors. Some of these abstractions are more common than others and are observed in different projects and used by more people. These abstractions lead to the creation of a common vocabulary, which additionally helps in communication and understanding. Everybody knows certain data structures such as trees and hash maps, and so there is no need to get into detail about them because their behavior and requirements are well known. Similarly, when someone gains enough experience in design patterns, they can see them and easily apply the patterns to the problems they are trying to tackle.

In this chapter, we will try to look at monoids, monads, and functors from a point of view, which...