On Sat, Sep 3, 2011 at 19:34, Daniel Peebles
Of course, the fact that the return method is explicitly mentioned in my example suggests that unless we do some real voodoo, Applicative would have to be a superclass of Monad for this to make sense. But with the new default superclass instances people are talking about in GHC, that doesn't seem too unlikely in the near future. ...
One way to avoid explicitly mentioning return would be to use monad comprehension syntax, which uses return implicitly, instead of do notation. This also has the advantage of being "new" in GHC 7.2, rather than officially being part of Haskell 98/2010, and therefore being more amenable to various extensions (e.g. there are already extensions that use MonadPlus/MonadZip/MonadGroup). Applicative would probably still have to be a superclass of Monad, but the translation of this syntax is simpler. Shachaf