Controlling a fetch

gistfile1.md

A Request object is needed to fetch. A Response object is the result. fetch() starts the process. How do we control it?

1. fetch(req); req.abort()
2. var f = fetch(req); f.abort() (subclassing promises seems to clash with upcoming async/await syntax)
3. fetch(req, handle(a) { a() })
4. fetch(req, { control:true }).then(con) { con.abort() } (fetch() would resolve immediately; control object would also have con.response or some such returning a promise)
5. var c = req.send(); c.abort() } (get the control object synchronously)
6. fetchRegistry.last.abort() (have some kind of global registry for all fetches made within the environment)

1. fetch(req).abort() but with an attribute to the response promise like fetch(req).ready.then().