[Haskell-cafe] The difference between ($) and application
andres at cs.uu.nl
Tue Dec 14 12:16:26 EST 2004
> Date: Tue, 14 Dec 2004 10:24:15 -0500
> From: Andrew Pimlott <andrew at pimlott.net>
> Subject: Re: [Haskell-cafe] The difference between ($) and application
> On Tue, Dec 14, 2004 at 11:23:24AM +0100, Henning Thielemann wrote:
> > On Tue, 14 Dec 2004, Andrew Pimlott wrote:
> > > (Of course, it's still useful, by itself or in a slice, as a higher-order
> > > operator.)
> > You can also use 'id' in this cases, right?
> I'm thinking of things like
> zipWith ($)
> map ($ x)
You can indeed use
map (`id` x)
instead. Look at the types:
id :: a -> a
($) :: (a -> b) -> (a -> b)
The function ($) is the identity function,
restricted to functions.
Nevertheless, I find using ($) in such a situation
more descriptive than using id.
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