That's one place where the Haskell version is perhaps clearer, since Haskell's return x will never evaluate to Nothing... See [1] if you'd like to read about it.
The behaviour you describe is a quirk of c.c.monads' maybe-m implementation which does not allow nil as a monadic value, since it's being used as m-zero instead. You could say that the implicit universal quantifier binding 'value' in the monadic law you cite has to be taken, in the context of maybe-m, to be restricted to non-nil values: \forall value . (not (nil? value)) => ... (And for a pure monadic experience, one could argue you should not even use m-result with a nil argument... The fact that nothing prevents you from doing so if you want to adds to the flexibility of maybe-m and so is seen to be ultimately beneficial.) Hope this helps somewhat, Michal [1] http://en.wikipedia.org/wiki/Monad_(functional_programming) -- 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 Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
