Proposal: Control.Concurrent.Async

[Ross Paterson]

On Fri, Jun 08, 2012 at 09:37:16AM +0100, Simon Marlow wrote:
> I'm opening this up for discussion so that we can tidy up any 
> inconsistent details and add any functions that people feel are missing. 
>   Naming is obviously up for discussion too.

I'd expect the arguments of cancelWith to be the other way round.
Then you could say

  cancel = cancelWith ThreadKilled

An alternative, equivalent interface for waitEither and friends would be

  waitEither :: Async a -> Async a -> IO (Either SomeException a)
  waitEitherThrow :: Async a -> Async a -> IO a

This might be conceptually simpler, leaving it to the user to decide
whether to mark the results with Left/Right, or something else, or not.
Similarly the Async now returned by waitAny and friends could be left
to the user.  That would leave the two sets of functions more in line.