SweetJS Macros for throw cancel and catch cancel

These SweetJS macros implement the language extensions from "Canceled as a third state", in particular throw cancel and catch cancel. They are fairly rough and exists only in service of some experiments I'm doing, so be careful.

Usage

npm install -g sweet.js
npm install throw-catch-cancel-syntax
sjs -m throw-catch-cancel-syntax your-file.js

Also, somewhere in the top level of your program, you need to do

require("throw-catch-cancel-syntax/ignore-unhandled-cancels");

to avoid program crashes when cancelations bubble to the top of the stack. (This is an important part of the semantics of cancelations; see the linked document.)

You should run as much code as you can through the macro. Anything that is not macro-ified will have the original try/catch statements, which catch cancelations as if they were exceptions. So ideally you'd run your test framework and dependencies and such through it. Unfortunately SweetJS has a lot of parsing bugs that make this hard in the general case (e.g. code without semicolons breaks it).