On Sat, Jun 16, 2012 at 3:31 PM, Corentin Dupont
Hi Alexander, sorry my initial example was maybe misleading. What I really what to do is to associate each event with an arbitrary data type. For example, consider the following events: NewPlayer NewRule Message User
I want to associate the following data types with each, to pass to there respective handlers: NewPlayer ---> Player NewRule ---> Rule Message ---> String User ---> String
Message and User have the same data type associated, that's why we can't use this type as a key to index the event...
In that case, you definitely want FunctionalDependencies or TypeFamilies, and will probably want to drop the constraint (Handler e d) on Event e (if it doesn't work), and maybe enforce it with explicit exports.