# JScript **NOTE: This had nothing to do with Microsoft's dialect of EcmaScript** **WARNING: Currently, this code is undocumented. Proceed with caution and a psychiatrist.** JScript is an engine, capable of running EcmaScript 5, written entirely in Java. This engine has been developed with the goal of being easy to integrate with your preexisting codebase, **THE GOAL OF THIS ENGINE IS NOT PERFORMANCE**. My crude experiments show that this engine is 50x-100x slower than V8, which, although bad, is acceptable for most simple scripting purposes. Note that although the codebase has a Main class, this isn't meant to be a standalone program, but instead a library for running JavaScript code. ## Example The following is going to execute a simple javascript statement: ```java var engine = new Engine(); // Initialize a standard environment, with implementations of most basic standard libraries (Object, Array, Symbol, etc.) var env = Internals.apply(new Environment()); // Queue code to load internal libraries and start engine var awaitable = engine.pushMsg(false, env, new Filename("tmp", "eval"), "10 + Math.sqrt(5 / 3)", null); // Run the engine on the same thread, until the event loop runs empty engine.run(true); // Get our result System.out.println(awaitable.await()); ```