Proposal: Add bool to Data.Bool

[Greg Fitzgerald]

I'd prefer something more like:

    mux :: Enum b => [a] -> b -> a
    mux xs x = xs !! fromEnum x

so then 'bool' could be implemented as:

    bool :: a -> a -> Bool -> a
    bool f t = mux [f, t]

but 'mux' needs a stronger type signature.  The size of the enum is
known at compile-time.  Is there any way to constrain the input list
to be the same size?

Thanks,
Greg




On Wed, Sep 11, 2013 at 2:18 AM, Simon Hengel <sol at typeful.net> wrote:
> On Tue, Sep 10, 2013 at 11:02:19PM +0100, Oliver Charles wrote:
>> I would like to propose that the following is added to Data.Bool in base:
>>
>> bool :: a -> a -> Bool -> a
>> bool f _ False = f
>> bool _ t True  = t
>
> +1
> _______________________________________________
> Libraries mailing list
> Libraries at haskell.org
> http://www.haskell.org/mailman/listinfo/libraries