[Haskell-beginners] Is there an idiom for this?

[鲍凯文]

I think i saw a relevant stackoverflow question before, but I can't find
it. Anyways, the answer said something like:

liftA2 (&&) pred1 pred2

which has the type a -> Bool, as desired. The reader applicative gives your
input to both predicates and (&&) is applied to their results. Hope I
remembered this correctly.
On Nov 16, 2015 4:01 AM, <beginners-request at haskell.org> wrote:

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>    1.  Is there an idiom for this? (Mark Carter)
>    2. Re:  Is there an idiom for this? (emacstheviking)
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> Message: 1
> Date: Mon, 16 Nov 2015 11:44:35 +0000
> From: Mark Carter <alt.mcarter at gmail.com>
> To: beginners at haskell.org
> Subject: [Haskell-beginners] Is there an idiom for this?
> Message-ID: <5649C1A3.1010901 at gmail.com>
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> Suppose I want to use an argument twice, as for example in the expression:
> (\x -> (pred1 x) and (pred2 x))
>
> Is there a shorter way of doing this?
>
>
> ------------------------------
>
> Message: 2
> Date: Mon, 16 Nov 2015 11:53:28 +0000
> From: emacstheviking <objitsu at gmail.com>
> To: The Haskell-Beginners Mailing List - Discussion of primarily
>         beginner-level topics related to Haskell <beginners at haskell.org>
> Subject: Re: [Haskell-beginners] Is there an idiom for this?
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> I guess it depends on the final use cases... you could use currying to
> partially evaluate some stuff ready, locked and loaded as it were but the
> example you have  given shows to distinct functions pres1 and pred2.
>
> I guess the short answer is "yes" but it depends on how you do it!
>
> :)
> Sean
>
>
> On 16 November 2015 at 11:44, Mark Carter <alt.mcarter at gmail.com> wrote:
>
> > Suppose I want to use an argument twice, as for example in the
> expression:
> > (\x -> (pred1 x) and (pred2 x))
> >
> > Is there a shorter way of doing this?
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