Book Image

Mastering JavaScript Functional Programming

By : Federico Kereki
Book Image

Mastering JavaScript Functional Programming

By: Federico Kereki

Overview of this book

Functional programming is a programming paradigm for developing software using functions. Learning to use functional programming is a good way to write more concise code, with greater concurrency and performance. The JavaScript language is particularly suited to functional programming. This book provides comprehensive coverage of the major topics in functional programming with JavaScript to produce shorter, clearer, and testable programs. You’ll delve into functional programming; including writing and testing pure functions, reducing side-effects, and other features to make your applications functional in nature. Specifically, we’ll explore techniques to simplify coding, apply recursion for loopless coding, learn ways to achieve immutability, implement design patterns, and work with data types. By the end of this book, you’ll have developed the JavaScript skills you need to program functional applications with confidence.
Table of Contents (22 chapters)
Title Page
About the Author
About the Reviewer
Customer Feedback
Connecting Functions - Pipelining and Composition
Answers to Questions

Chapter 6. Producing Functions - Higher-Order Functions

In Chapter 5, Programming Declaratively - A Better Style, we worked with some predefined higher-order functions and were able to see how their usage let us write declarative code, gaining in understandability as well as in compactness. In this new chapter, we are going to go further in the direction of higher-order functions, and we are going to develop our own. We can roughly classify the kinds of functions that we are going into three groups:

  • Wrapped functions, that keep their original functionality, adding some kind of new feature. In this group, we can consider logging (adding log production capacity to any function), timing (producing time and performance data for a given function), and memoization (that caches results to avoid future re-work).
  • Altered functions, that differ in some key point with their original versions. Here we can include the once() function (we wrote it in Chapter 2, Thinking Functionally - A First Example...