25 Jan
2007
25 Jan
'07
2:27 p.m.
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. Thanks Neil