2009/05/18 Miguel Mitrofanov <miguelim...@yandex.ru>: > On 19 May 2009, at 09:06, Ryan Ingram wrote: > >> This is a common problem with trying to use do-notation; there are >> some cases where you can't make the object an instance of Monad. The >> same problem holds for Data.Set; you'd can write >> >> setBind :: Ord b => Set a -> (a -> Set b) -> Set b >> setBind m f = unions (map f $ toList m) >> >> but there is no way to use setBind for a definition of >>= > > You can use a continuation trick.
Trick? -- Jason Dusek _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
