[Haskell-cafe] Re: A function for Maybes

Neil Mitchell ndmitchell at gmail.com
Thu Jan 25 14:27:17 EST 2007

Hi Alan,

> Usually, when I have a question like this, I try Hoogle first:
> http://www.haskell.org/hoogle/?q=%28a+-%3E+b%29+-%3E+Maybe+a+-%3E+Maybe+b
> Unfortunatly, the right answer (fmap) is on the second page of results.

The reason for this is that Hoogle 3 doesn't understand higher-kinded
type classes, i.e. Monad and Functor, which means that fmap doesn't
match as closely as it should do. Hoogle 4 would give fmap as the
first result, I'm pretty sure.

> (I am really excited for the new version of Hoogle, its supposed to be
> pretty close to release)

Me too, but you'll probably have to wait a few more months yet - but
the various components are coming together nicely.



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