Re: [Haskell-cafe] Categories in base

On 10/14/07, Jean-Philippe Bernardy wrote:

instance Arrow a => Functor (a r) where -- (not defined as such in base, but ad-hoc) f <$> g = pure f . g

Similarly: instance Arrow a => Applicative (a r) where return a = pure (const a) a <*> b = pure (\(f,x) -> f x) . a &&& b -- Dave Menendez http://www.eyrie.org/~zednenem/