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. _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
