Book Image

JavaScript : Functional Programming for JavaScript Developers

By : Ved Antani, Simon Timms, Dan Mantyla
Book Image

JavaScript : Functional Programming for JavaScript Developers

By: Ved Antani, Simon Timms, Dan Mantyla

Overview of this book

JavaScript is a high-level, dynamic, untyped, lightweight, and interpreted programming language and functional programming is a style that emphasizes and enables smarter code that minimizes complexity and increases modularity. It's a way of writing cleaner code through clever ways of mutating, combining, and using functions. And JavaScript provides an excellent medium for this approach. By learning how to expose JavaScript's true identity as a functional language, we can implement web apps that are more powerful, easier to maintain and more reliable. The java script: Functional Programming for JavaScript Developers course will take you on a journey to show how functional programming when combined with other techniques makes JavaScript programming more efficient. The first module Mastering JavaScript, stress on practical aspects of Javascript development like—Functions and Closures, Runtime debugging techniques, project layout, events and DOM processing, build tools, Object-oriented patterns, isomorphism—everything that a modern Javascript project would need. The second module, Mastering JavaScript Design Patterns - Second Edition, will explore how design patterns can help you improve and organize your JavaScript code. You’ll get to grips with creational, structural, and behavioral patterns as you discover how to put them to work in different scenarios. This updated edition will also delve into reactive design patterns and microservices as they are a growing phenomenon in the world of web development. It will also show you some advanced patterns, including dependency injection and live post processing. The third module, Functional Programming in JavaScript, will help you to write real-world applications by utilizing a wide range of functional techniques and styles. It explores the core concepts of functional programming common to all functional languages, with examples of their use in JavaScript.
Table of Contents (6 chapters)

Chapter 7. Reactive Programming

I once read a book that suggested that Newton came up with the idea for calculus when he was observing the flow of a river around a reed. I've never been able to find any other source which supports that assertion. It is, however, a nice picture to hold in your mind. Calculus deals with understanding how the state of a system changes over time. Most developers will rarely have to deal with calculus in their day to day work. They will, however, have to deal with systems changing. After all, having a system which doesn't change at all is pretty boring.

Over the last few years a number of different ideas have arisen in the area of treating change as a stream of events – just like the stream that Newton supposedly observed. Given a starting position and a stream of events it should be possible to figure out the state of the system. Indeed, this is the idea behind using an event store. Instead of keeping the final state of an aggregate...