Book Image

Learn Type-Driven Development

By : Yawar Amin, Kamon Ayeva
Book Image

Learn Type-Driven Development

By: Yawar Amin, Kamon Ayeva

Overview of this book

Type-driven development is an approach that uses a static type system to achieve results including safety and efficiency. Types are used to express relationships and other assumptions directly in the code, and these assumptions are enforced by the compiler before the code is run. Learn Type-Driven Development covers how to use these type systems to check the logical consistency of your code. This book begins with the basic idea behind type-driven development. You’ll learn about values (or terms) and how they contrast with types. As you progress through the chapters, you’ll cover how to combine types and values inside modules and build structured types out of simpler ones. You’ll then understand how to express choices or alternatives directly in the type system using variants, polymorphic variants, and generalized algebraic data types. You’ll also get to grips with sum types, build sophisticated data types from generics, and explore functions that express change in the types of values. In the concluding chapters, you’ll cover advanced techniques for code reuse, such as parametric polymorphism and subtyping. By end of this book, you will have learned how to iterate through a type-driven process of solving coding problems using static types, together with dynamic behavior, to obtain more safety and speed.
Table of Contents (12 chapters)

Who this book is for

If you've ever wrestled with this problem: Undefined is not a function, then this book might be for you. If you're looking for a way to write less defensive code, fewer trivial tests, and not worry about breaking code if you try to refactor, then you may be interested in the concepts of type-driven development.

This book is for you if you are a programmer (it doesn't matter what kind) who's interested in writing safe, efficient code. There are many techniques and processes for achieving that, of course, but type-driven development is one of the most mainstream and accessible.

That being said, this book presents type-driven development using a relatively unfamiliar language. I've tried to write as plainly as possible; but to follow along, you'll still need to learn the rules and logic of a powerful type system. You will reach a point where your mind works in tandem with the compiler, but that will take time and patience. The reward will be that the compiler becomes your friend in writing safer and more correct code.

If you're willing to go on this journey and learn the rules of the type system, then this book is for you.