Using Maybe

Maybe is a sum type very often used to indicate a NULL value or nothing. In fact, it is a very type-safe way of representing a NULL value. Explicitly saying that we have either a value or nothing makes our life simpler during programming steps, which can fail, and we may not want to continue.

In this recipe, you will learn to use the Maybe data type.

Getting ready

Create a new project called using-maybe using the simple stack template. Change into the directory and build the solution:

    stack new using-maybe simple
    stack build

How to do it...

1. Open src...