Re: [Haskell-beginners] Re: Either Monadic Trouble

This is all very confusing. You say that it is defined in the transformers. Does this mean it is possible to use the code I am trying to get to work to do what I want? You also mention the attempt package, I must admit that I am not entirely sure how to use it either. Note that I haven't done a lot of error handling in haskell (the extent usually involved Maybe) - iæfai. On 2009-11-09, at 4:00 PM, Nicolas Pouillard wrote:

Excerpts from Ertugrul Soeylemez's message of Mon Nov 09 21:44:44 +0100 2009:

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Nicolas Pouillard wrote:

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Either is not a monad, you can check this by typing :i Either in GHCi; you will not see a line like instance Monad Either in the result. Compare this to :i Maybe

In fact the Either Monad instance is defined in the 'transformers' (or 'mtl') packages.

Either is still not a monad. Have a look at its kind.

OK, right Either is not but (Either e), where e must be in the Error type class.

-- Nicolas Pouillard http://nicolaspouillard.fr _______________________________________________ Beginners mailing list Beginners@haskell.org http://www.haskell.org/mailman/listinfo/beginners