On Mon, Dec 22, 2008 at 06:19:07PM +0100, Peter Padawitz wrote: > I'd like to define a monad Set for types in the class Eq. But how can the > arguments of Set be constrained when Set is defined as an instance of > Monad? instance Eq a => Monad Set where ... obviously cannot work. > > Is there a standard update function for fields in data types, something > that OO programmers do with assignments like obj.attr := value ? > > Peter >
Note there is already a package on Hackage to do exactly this, rmonad. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/rmonad -Brent _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
