[Haskell-cafe] Re: Instances for Set of Functor, Traversable?

Ivan Lazar Miljenovic ivan.miljenovic at gmail.com
Tue Jul 27 06:23:24 EDT 2010

oleg at okmij.org writes:

> class Functor' f a b where
>     fmap' :: (a -> b) -> f a -> f b

I was about to ask why you mentioned b in the type signature as well, as
I thought just having "(Functor' f b)" as a constraint in the type
signature of fmap' would be sufficient, but when I went to check I found
that I was mistaken.

*sigh* this is going to make some of my code even uglier than it already
 is :(

Ivan Lazar Miljenovic
Ivan.Miljenovic at gmail.com

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