[Haskell-beginners] \x -> x < 0.5 && x > -0.5

[Magnus Therning]

On Mon, Oct 19, 2009 at 9:49 AM, Michael Mossey <mpm at alumni.caltech.edu> wrote:
> Is there a nifty way to write
>
> filter (\x -> x < 0.5 && x > -0.5) xs
>
> without explicitly using x?
>
> Maybe arrows? I have a vague understanding that arrows can "send" an
> argument to more than one computation.

Using &&& from Control.Arrow you can write something like

    file (uncurry (&&) . ((< 0.5) &&& (> -0.5))) xs

/M

-- 
Magnus Therning                        (OpenPGP: 0xAB4DFBA4)
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