On Mon, Dec 21, 2009 at 12:39:06AM +0100, Daniel Fischer wrote:
Am Sonntag 20 Dezember 2009 23:25:02 schrieb Jamie Morgenstern:
Also, I was wondering if something akin to a "parallel or" exists. By this, I mean I am looking for a function which, given x : a , y : a, returns either, whichever computation returns first.
This wouldn't be easy to reconcile with referential transparency. You can do that in IO, roughly
m <- newEmptyMVar t1 <- forkIO $ method1 >>= putMVar m t2 <- forkIO $ method2 >>= putMVar m rs <- takeMVar m killThread t1 killThread t2 return rs
But in pure code, I think not.
There's 'unamb' in Hackage, however I think you should carefully understand its implementation details before using it. Not that I use it myself. Link: http://hackage.haskell.org/package/unamb -- Felipe.