Learning Functional Programming in Go

Type classes

Type classes allow us to define behavior on types.

As discussed in Chapter 3, Using High-Order Functions, type classes add an additional layer to our type system.

We accomplish this by:

1. Defining behavior using Go interfaces (parent type class)
2. Declaring a new type (base type class) to wrap base types
3. Implementing behavior on our new type classes

Let’s look at our Equals type class implementation.

Parent class definition:

//4-purely-functional/ch11-monads/05_typeclasss/src/typeclass/equals.gopackage typeclassimport (   "strconv")type Equals interface {   Equals(Equals) bool}

Equals is our parent type class. All base classes must implement the Equals method.