Sebastian Fischer <s...@informatik.uni-kiel.de> writes: >> Furthermore, as I said earlier, >> it doesn't make sense to constrain the label type just to make an >> instance of a type class. >> >> (Now, if we had other functions in there which _might_ depend on the >> label types, this _would_ make sense; as it stands however, it >> doesn't.) >> >> You'll notice that my empty does depend on a having a Cls instance >> because it will fail to compile. [...] I'm not understanding your >> point, and I suspect you're not understanding mine :) > > Let's assume he did understand your point. I think Ivan doubt's that > there is any real need for the change because (while defining the set > monad may make sense) "it does not make sense" to wish for being able > to use additional constraints when defining the specific functions > that are currently in the Graph class.
My objections were that there are no ways any such Graph instance would/should use any of the label values when defining definitions for the various methods; the labels are just meant to be extra things _attached_ to the nodes and edges. > I'm not sure if I agree. It would be interesting to see whether the > real graph behind the original problem is an example where such > additional constraints are really necessary and make sense. Well, yes, having Kevin actually responding back would help ;-) -- Ivan Lazar Miljenovic ivan.miljeno...@gmail.com IvanMiljenovic.wordpress.com _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe