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

Converting Rust into WebAssembly via Cargo

Cargo makes it easier to create, run, download, compile, test, and run your project. The cargo command provides a wrapper that calls the rustc compiler to start the compilation. In order to create WebAssembly modules using Rust's toolchain, we will be using a different target, wasm32-unknown-unknown.

The wasm32-unknown-unknown target adds zero runtime and toolchain footprint. wasm32 makes the compiler assume that only the wasm32 instruction set is present. The first unknown in unknown-unknown indicates the code can compile on any machine and the second indicates the code can run on any machine.

To see it in action, let's create a new project with Cargo:

$ cargo new --lib fib_wasm
Created library `fib_wasm` package

A new project called fib_wasm is created. The new option creates a Rust project. The --lib flag informs Cargo to create a new library project rather than the default binary project.

The binary project will...