It's the Endo monoid.

λ> :t ala Endo foldMap -- see newtype package
ala Endo foldMap :: Foldable t => t (a -> a) -> a -> a
λ> ala Endo foldMap [(+1), (*2)] 8
17
λ> :i ala
ala ::
(Newtype n o, Newtype n' o') =>
(o -> n) -> ((o -> n) -> b -> n') -> b -> o'
-- Defined in Control.Newtype

On 27/10/12 04:41, Greg Fitzgerald wrote:

Hi Haskellers,

I've recently found myself using the expression: "foldr (.) id" to compose
a list (or Foldable) of functions.  It's especially useful when I need to
map a function over the list before composing.  Does this function, or the
more general "foldr fmap id", defined in a library anywhere?  I googled and
hoogled, but no luck so far.

Thanks,
Greg


_______________________________________________
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe

-- 
Tony Morris
http://tmorris.net/