Book Image

Practical WebAssembly

By : Sendil Kumar Nellaiyapen
Book Image

Practical WebAssembly

By: Sendil Kumar Nellaiyapen

Overview of this book

Rust is an open source language tuned toward safety, concurrency, and performance. WebAssembly brings all the capabilities of the native world into the JavaScript world. Together, Rust and WebAssembly provide a way to create robust and performant web applications. They help make your web applications blazingly fast and have small binaries. Developers working with JavaScript will be able to put their knowledge to work with this practical guide to developing faster and maintainable code. Complete with step-by-step explanations of essential concepts, examples, and self-assessment questions, you’ll begin by exploring WebAssembly, using the various tools provided by the ecosystem, and understanding how to use WebAssembly and JavaScript together to build a high-performing application. You’ll then learn binary code to work with a variety of tools that help you to convert native code into WebAssembly. The book will introduce you to the world of Rust and the ecosystem that makes it easy to build/ship WebAssembly-based applications. By the end of this WebAssembly Rust book, you’ll be able to create and ship your own WebAssembly applications using Rust and JavaScript, understand how to debug, and use the right tools to optimize and deliver high-performing applications.
Table of Contents (15 chapters)
Section 1: Introduction to WebAssembly
Section 2: WebAssembly Tools
Section 3: Rust and WebAssembly

Chapter 3: Exploring WebAssembly Modules

WebAssembly is a low-level assembly-like code that is designed for efficient execution and compact representation. WebAssembly runs at a near-native speed in all JavaScript engines (including modern desktop and mobile browsers and Node.js). Compact representation of the binary enables the generated binary to be as small as possible in size.


The main goal of WebAssembly is to enable high-performance applications.

Each WebAssembly file is an efficient, optimal, and self-sufficient module called a WebAssembly module (WASM). WASM is safe, that is, the binary runs in a memory-safe and sandboxed environment. WASM does not have permission to access anything outside of that sandbox. WASM is language-, hardware-, and platform-independent.

WebAssembly is a virtual instruction set architecture (ISA). The WebAssembly specifications define the following:

  • Instruction set
  • Binary encoding
  • Validation
  • Execution semantics...