14 Oct
2007
14 Oct
'07
8:56 p.m.
On 10/14/07, Jean-Philippe Bernardy <jeanphilippe.bernardy@gmail.com> 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 <dave@zednenem.com> <http://www.eyrie.org/~zednenem/>