cancellation

This library solves a common problem in JavaScript: how to stop an operation that's already running. Imagine you start downloading a file, but the user closes the app or navigates away—you want that download to actually stop, not keep running silently in the background wasting resources.

The library gives you a way to create a "cancellation token," which is like a remote control for async operations. You pass this token to whatever async function you're running, then at any point you can hit cancel. The function can check if it's been cancelled and clean up (abort the download, stop the loop, etc.) before exiting. The README doesn't explain what "async operations" means in detail, but the examples show things like HTTP requests and looping functions that take time to complete.

Here's how it works in practice: you create a token source using the library, which gives you both a token (to pass to your async function) and a way to cancel it. Inside your async function, you check the token periodically—either by calling a method to see if it's been cancelled, or by registering a callback that runs when cancellation happens. When you're done with the operation, you call cancel on the source, which triggers your cleanup code.

The library is most useful for scenarios like network requests that you might want to abort, long-running computations you want to interrupt, or any situation where you're managing multiple async tasks and need a clean way to shut them down. Developers building web apps, Node.js servers, or any JavaScript system with background operations would find this helpful. Instead of having orphaned requests or background processes, you get a standard pattern for stopping them gracefully.