webassemblyjs

What is webassemblyjs?

The webassemblyjs package is a collection of tools designed to work with WebAssembly (Wasm) modules. It provides functionalities for parsing, editing, and generating WebAssembly binary and text formats, making it useful for developers working with Wasm directly.

What are webassemblyjs's main functionalities?

Parsing WebAssembly

This feature allows you to parse a WebAssembly binary into an Abstract Syntax Tree (AST). The code sample demonstrates how to use the wasm-parser module to decode a binary into its AST representation.

const { decode } = require('@webassemblyjs/wasm-parser');
const binary = new Uint8Array([0x00, 0x61, 0x73, 0x6d]);
const ast = decode(binary);
console.log(ast);

Editing WebAssembly

This feature provides the ability to edit a WebAssembly AST. The code sample shows how to modify an export name within an AST using the edit function from the ast module.

const { edit } = require('@webassemblyjs/ast');
const ast = {}; // Assume this is a pre-existing AST
edit(ast, {
  ModuleExport: ({ node }) => {
    node.name = 'newExportName';
  }
});

Generating WebAssembly

This feature allows you to generate a WebAssembly binary from an AST. The code sample demonstrates how to use the wasm-gen module to encode an AST back into a binary format.

const { encode } = require('@webassemblyjs/wasm-gen');
const ast = {}; // Assume this is a pre-existing AST
const binary = encode(ast);
console.log(binary);

Other packages similar to webassemblyjs

assemblyscript

AssemblyScript is a TypeScript-like language that compiles to WebAssembly. Unlike webassemblyjs, which focuses on parsing and manipulating existing Wasm binaries, AssemblyScript is used to write new WebAssembly modules in a high-level language.

wasm-bindgen

wasm-bindgen is a tool for facilitating high-level interactions between WebAssembly modules written in Rust and JavaScript. It differs from webassemblyjs by focusing on Rust-to-Wasm compilation and JavaScript bindings, rather than low-level Wasm manipulation.

binaryen

Binaryen is a compiler and toolchain infrastructure library for WebAssembly, written in C++. It provides optimization and transformation tools for Wasm binaries. While webassemblyjs is JavaScript-based and focuses on parsing and editing, Binaryen is more about optimizing and compiling WebAssembly code.

README

webassemblyjs

WebAssembly interpreter

This is meant to be a polyfill entirely written in JavaScript.

See WebAssembly.js.org for more information.

Installation

yarn add webassemblyjs

Usage

import WebAssembly from "webassemblyjs";

WebAssembly.instantiate(buff)

See WebAssembly MDN documentation for more information about the WebAssembly API.