Re: [Haskell-cafe] Join a transformer

If something like MMonad gets added to transformers, then its MFunctor version should really be double-ended to work with things like the final version of FreeT. On Mon, Apr 9, 2018, 9:41 AM Daniel Díaz Casanueva wrote:

+1 on adding this to transformers.

2018-04-09 14:45 GMT+02:00 Ross Paterson :

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On Thu, Mar 14, 2013 at 05:24:23AM +0200, Michael Snoyman wrote:

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I'm wondering if this pattern exists and has a name. We have the concept of joining a Monad: join :: Monad m => m (m a) -> ma How about joining a monad transformer? joinT :: (Monad m, MonadTrans t) => t (t m) a -> t m a

This is a monad in the category of monads. Moggi discusses them in "An Abstract View of Programming Languages", including which transformers have joinT. I was thinking of adding the class to the transformers package. _______________________________________________ Haskell-Cafe mailing list To (un)subscribe, modify options or view archives go to: http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe Only members subscribed via the mailman list are allowed to post.

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