vm.js

Javascript bytecode compiler/vm that should run in any ECMAScript 3 compatible environment

Installation

npm install vm.js

Overview

vm.js is a library that implements a javascript virtual machine that can be used as simple sandbox(preventing infinite loops and global leaks) or as async API adapter(it implements fibers that can be paused and resumed later).

Eventually this will provide a complete ECMAScript 6 environment.

Example usage on node.js

> Vm = require('vm.js').Vm // On web browsers use the 'vmjs' global object
> vm = new Vm()
> vm.eval('40 + 2')
42
> vm.eval('[a, b, c] = [1, 2, 3]')
[1, 2, 3]
> vm.realm.global.a
1
> vm.realm.global.b
2
> vm.realm.global.c
3

Comments

This was inspired by Continuum which is a ECMAScript 6 virtual machine implemented in pure javascript. I wrote this because I wanted a smaller codebase(about 3k lines of coffeescript code) and better integration with the host virtual machine(no need to call strange internal methods to access objects manipulated by the vm).

For parsing source code this library uses the esprima parser.