[Haskell-cafe] Sequence of lifting transformation operators

[Erik de Castro Lopo]

Tyson Whitehead wrote:

> <$$> :: (a -> b -> c) -> f a -> f b -> f c

I'd just like to point out that this operator is often used by
as the oeprator for fmap2:


  (<$$>) :: (Functor f1, Functor f) => (a -> b) -> f (f1 a) -> f (f1 b)
  (<$$>) = fmap . fmap

Erik
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Erik de Castro Lopo
http://www.mega-nerd.com/