Learn Type-Driven Development

More Information
  • Use static types to capture information, making programs safer and faster
  • Learn ReasonML from experienced type-driven developers
  • Enhance safety by simply using basic types
  • Understand the most important type-driven concepts with simple examples
  • Explore a design space using static typing and find the best way to express your system rules
  • Use static types and dynamic runtime in harmony to write even safer and faster code

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.

  • Reduce code errors with the power of type systems
  • Employ static typechecking and genericity to promote code reuse and consistency
  • Understand functional programming which is the foundation of type-driven development
Page Count 180
Course Length 5 hours 24 minutes
ISBN 9781788838016
Date Of Publication 26 Dec 2018
Type inference and generic types
The list – modeling more than one
The option – modeling either none or one
Mutable parameterized types – ref and array
Forcing a difference with phantom types


Yawar Amin

Yawar Amin is a software engineer by profession, with a background in statistics and econometrics. He has worked professionally with Scala and JavaScript, and as a result, developed a keen interest in type-safe programming.

Kamon Ayeva

Kamon Ayeva is a web developer / DevOps engineer working with a variety of tools. He spends most of his time in building projects, using Python's powerful scripting capabilities, add-on libraries and web frameworks such as Django or Flask. Kamon has been using Python in professional contexts for more than 12 years. Based on his recent experience using the type system that was added to Python 3 as well as developing a user interface using the React framework, he lately started exploring type-driven development in JavaScript.