Book Image

Haskell Cookbook

Book Image

Haskell Cookbook

Overview of this book

Haskell is a purely functional language that has the great ability to develop large and difficult, but easily maintainable software. Haskell Cookbook provides recipes that start by illustrating the principles of functional programming in Haskell, and then gradually build up your expertise in creating industrial-strength programs to accomplish any goal. The book covers topics such as Functors, Applicatives, Monads, and Transformers. You will learn various ways to handle state in your application and explore advanced topics such as Generalized Algebraic Data Types, higher kind types, existential types, and type families. The book will discuss the association of lenses with type classes such as Functor, Foldable, and Traversable to help you manage deep data structures. With the help of the wide selection of examples in this book, you will be able to upgrade your Haskell programming skills and develop scalable software idiomatically.
Table of Contents (13 chapters)

Defining a product type

In this recipe, we will look at product types. We will define simple data types with two parameters, and then will do different experiments with it.

Getting ready

Create a new project called product-type using the simple Stack template:

stack new product-type simple

Change the working directory to product-type.

How to do it...

  1. Open src/Main.hs for editing.
  2. Add the following data definitions for product types:
        data Product1 = Product1 Bool deriving Show
data Product2 = Product2 Bool Bool deriving Show
data Product3 a = Product3...