Book Image

Hands-On Functional Programming with TypeScript

By : Remo H. Jansen
Book Image

Hands-On Functional Programming with TypeScript

By: Remo H. Jansen

Overview of this book

Functional programming is a powerful programming paradigm that can help you to write better code. However, learning functional programming can be complicated, and the existing literature is often too complex for beginners. This book is an approachable introduction to functional programming and reactive programming with TypeScript for readers without previous experience in functional programming with JavaScript, TypeScript , or any other programming language. The book will help you understand the pros, cons, and core principles of functional programming in TypeScript. It will explain higher order functions, referential transparency, functional composition, and monads with the help of effective code examples. Using TypeScript as a functional programming language, you’ll also be able to brush up on your knowledge of applying functional programming techniques, including currying, laziness, and immutability, to real-world scenarios. By the end of this book, you will be confident when it comes to using core functional and reactive programming techniques to help you build effective applications with TypeScript.
Table of Contents (14 chapters)
5
The Runtime – Closures and Prototypes

Working with Immutable.js

In the preceding chapters, we also learned about immutability and the benefits of using immutable data objects. We learned that we can use the readonly keyword to declare immutable objects:

class Street {

public readonly num: number;
public readonly name: string;

public constructor(num: number, name: string) {
this.num = num;
this.name = name;
}

}

class Address {

public readonly city: string;
public readonly street: Street;

public constructor(city: string, street: Street) {
this.city = city;
this.street = street;
}

}

We also learned that working with immutable objects can sometimes be very verbose and tedious and that lenses can help us to overcome these difficulties. We are now going to learn about a library that can help us to declare immutable objects. The library is known as Immutable.js, and it also...