Re: [Haskell-beginners] Monad for Pair

'Much better if you let us know the source of this problem. Is this an exercise from some book / online course?” The source is just me exploring. I first looked at data C a = C a deriving (Show) and made Monad, Applicative, Monoid and Functors for it. So then tried Pair a = P (a, a) and stuck on Monad. Thanks Mike

On 18 Nov 2015, at 07:23, Kim-Ee Yeoh mailto:ky3@atamo.com> wrote:

On Wed, Nov 18, 2015 at 4:41 AM, Mike Houghton mailto:mike_k_houghton@yahoo.co.uk> wrote:

And really return x = P (x, x) doesn’t seem correct anyway.

But if you look at the type, which is essentially "a -> (a,a)" there's only one way to write it, for the same reason that there's only one "a -> a" function.

Would someone please write the Monad with an explanation?

Much better if you let us know the source of this problem. Is this an exercise from some book / online course?

-- Kim-Ee _______________________________________________ Beginners mailing list Beginners@haskell.org mailto:Beginners@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners