The case of the missing Arrow function
L.S., The function 'liftA2' is mentioned in many documents about Arrows; yet I cannot find it in the Control.Arrow module, as it comes with GHC 6.10.1 and Hugs Sep 2006. Is there a special reason for this? -- Regards, Henk-Jan van Tuyl -- http://functor.bamikanarie.com http://Van.Tuyl.eu/ --
Hi Henk,
You're only a Hoogle away: http://haskell.org/hoogle/?hoogle=liftA2
Control.Applicative liftA2 :: Applicative f => (a -> b -> c) -> f a ->
f b -> f c
I guess its both an arrow function and an applicative function.
Thanks
Neil
On Fri, Jan 30, 2009 at 3:02 PM, Henk-Jan van Tuyl
L.S.,
The function 'liftA2' is mentioned in many documents about Arrows; yet I cannot find it in the Control.Arrow module, as it comes with GHC 6.10.1 and Hugs Sep 2006. Is there a special reason for this?
-- Regards, Henk-Jan van Tuyl
-- http://functor.bamikanarie.com http://Van.Tuyl.eu/ --
_______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
On Fri, Jan 30, 2009 at 03:05:52PM +0000, Neil Mitchell wrote:
You're only a Hoogle away: http://haskell.org/hoogle/?hoogle=liftA2
Control.Applicative liftA2 :: Applicative f => (a -> b -> c) -> f a -> f b -> f c
I guess its both an arrow function and an applicative function.
Ah, but this wasn't the function Henk was after. liftA2 on arrows is defined in the papers, but it's not in the library.
participants (3)
-
Henk-Jan van Tuyl -
Neil Mitchell -
Ross Paterson