[lomnakkus]

Hm? My point was that the spec doesn't fundamentally change anything wrt. the things you mentioned, so it should be evaluated on other merits (or lack thereof).

Doing ad-hoc hacks around the lack of cancellation seems like a pretty big practical issue to me[1], so I'd certainly like to see something like this spec in the standard.

(Note: something like, not necessarily exactly this. I haven't thought about it deeply enough to be able to properly evaluate the spec.)

[1] Happens all the time when doing simple Ajax-on-futures where you really just want to ignore any result if the operation gets canceled in the UI before the response arrives.