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

Composition techniques

In this section, we are going to learn about some functional programming techniques that are very closely linked to function composition. We are going to learn about composition, partial application, currying, and pipes.

Composition

Functional composition is a technique or pattern that allows us to combine multiple functions to create a more complex function.

The following code snippet declares two simple functions:

const trim = (s: string) => s.trim();
const capitalize = (s: string) => s.toUpperCase();

That two simple functions declared by the preceding code snippet are the following:

  • A function used to trim a string
  • A function used to transform a piece of text into uppercase

We can create a...