On Mon, 25 Jun 2007, Tomasz Zielonka wrote: > On Mon, Jun 25, 2007 at 10:29:14AM +0200, Henning Thielemann wrote: > > Imagine all performActions contain their checks somehow. Let > > performActionB take an argument. > > > > > do > > > x <- performActionA > > > y <- performActionB x > > > z <- performActionC > > > return $ calculateStuff x y z > > > > Now performActionB and its included check depend on x. That is, the check > > relies formally on the result of performActionA and thus check B must be > > performed after performActionA. > > IIUC, this limitation of Monads was one of the reasons why John Hughes > introduced the new Arrow abstraction.
How would this problem be solved using Arrows? _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
