Book Image

Mastering JavaScript Functional Programming - Second Edition

By : Federico Kereki
Book Image

Mastering JavaScript Functional Programming - Second Edition

By: Federico Kereki

Overview of this book

Functional programming is a paradigm for developing software with better performance. It helps you write concise and testable code. To help you take your programming skills to the next level, this comprehensive book will assist you in harnessing the capabilities of functional programming with JavaScript and writing highly maintainable and testable web and server apps using functional JavaScript. This second edition is updated and improved to cover features such as transducers, lenses, prisms and various other concepts to help you write efficient programs. By focusing on functional programming, you’ll not only start to write but also to test pure functions, and reduce side effects. The book also specifically allows you to discover techniques for simplifying code and applying recursion for loopless coding. Gradually, you’ll understand how to achieve immutability, implement design patterns, and work with data types for your application, before going on to learn functional reactive programming to handle complex events in your app. Finally, the book will take you through the design patterns that are relevant to functional programming. By the end of this book, you’ll have developed your JavaScript skills and have gained knowledge of the essential functional programming techniques to program effectively.
Table of Contents (17 chapters)
Technical Requirements

Transforming Functions - Currying and Partial Application

In Chapter 6, Producing Functions – Higher-Order Functions, we saw several ways of manipulating functions, to get new versions with some change in their functionality. In this chapter, we will go into a particular kind of transformation, a sort of factory method, that lets you produce new versions of any given function, with some fixed arguments.

We will be considering the following:

  • Currying: A classic FP theoretical function that transforms a function with many parameters into a sequence of unary functions.
  • Partial application: Another time-honored FP transformation, which produces new versions of functions by fixing some of their arguments.
  • Partial currying (a name of my own): Can be seen as a mixture of the two previous transformations.

To be fair, we'll also see that some of these techniques can...