[Haskell-cafe] Re: help with Haskell programming

Keith Sheppard keithshep at gmail.com
Sun Apr 18 13:21:54 EDT 2010


Using composition can be tricky with more than one arg. I just want to
be sure you're not really looking for something like:

> func :: (a -> Bool) -> (b -> Bool) -> (a -> b -> Bool)

keeping with your given type I think you're looking for something like:

> func f1 f2 x = (f1 x) || (f2 x)

I'm sure there is a nice way to do this with function composition but
I still find composition less intuitive than explicit args in cases
like this.

On Sun, Apr 18, 2010 at 1:00 PM, Mujtaba Boori <mujtaba.boori at gmail.com> wrote:
> Thanks for helping me but I have another problem (sorry for asking) . I
> tried to figure it out .
> how about if I want to compare two kind with (&&) (||)  for
> func :: (a -> Bool) -> (a -> Bool) -> (a -> Bool)
>
> I tried some thing like
> func = ((||) .)
> This is the annoying part about Haskell . I can not understand composition .
>
> On Sun, Apr 18, 2010 at 4:35 PM, Mujtaba Boori <mujtaba.boori at gmail.com>
> wrote:
>>
>> Hello I am kinda newbie in Haskell you can help help me with some
>> programming
>> I am trying to make function like for example
>> func :: (a -> Bool) -> (a -> Bool)
>> this function make calculation  and return bool . I want to be able to
>> make bool True when It is False and False when it is True while returning
>> the a.
>> Thank you
>> --
>> Mujtaba Ali Alboori
>
>
>
> --
> Mujtaba Ali Alboori
>
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-- 
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