Learning Functional Programming in Go

Identity operation

The identity law of our category says that the identity morphism of A is A:

If our operation is a map and the elements in our list are numbers, then the identity morphism is +0. If we add 0 to every element of our input list, our transformed list will consist of the same elements.

HEADS UP! We are going to hammer home the concept of composition. Your understanding of what composition is and how it works is essential to your ability to be productive in pure functional programming. If you read only a few pages in this book, let your reading begin now.