In the previous chapters, you created your own types. Now, it’s time to learn what classes are in Haskell and how to work with them. In this chapter, you’ll learn about the standard classes and then how to create your own classes.
Standard Classes
In Haskell, the most common standard classes are the following ones:
Eq is used when you work with == (is equal) and /= (is not equal).
Ord is used when you work with the operators <, <=, >, and >= and the functions min, max, and compare.
Enum is used in enumerations ...
