On 21.11.2008, at 20:10, Adam Jones wrote: >> The file contains the macro definitions, the definitions of three >> popular monads (maybe, list, state), and some illustrations of their >> use. Comments are welcome! > > Since they support mzero and mplus, aren't these equivalent to > Haskell's MonadPlus? (i.e. they're a little more than *just* monads)
You can define :plus and :zero if they are appropriate for a monad. If they are defined, you can use them. None of the predefined monad machinery will use them at the moment, but I plan to implement conditions, which work only if :zero is defined. In Haskell there are two different types of monads because of the type system, but the Clojure implementation doesn't use the type system at all, so :plus and :zero are simply used by convention. > I've been kicking around the idea of re-implementing Haskell > typeclasses on top of multimethods. Now that I think more about it, > this probably wouldn't be much work. You need to find a way to store the type information with the data. That is easy if you limit yourself to a specific data structure, say a map with a key reserved for type information. But if you want to be able to use typeclasses for general Clojure data (e.g. make sequences an instance of Monad), I don't see a simple way to do it. Konrad. --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/clojure?hl=en -~----------~----~----~----~------~----~------~--~---
