Re: PROPOSAL: Add 'Natural' type to base:Data.Word

On 13/11/14 05:35 PM, Brandon Allbery wrote:

On Thu, Nov 13, 2014 at 5:20 PM, Mario Blažević mailto:mblazevic@stilo.com> wrote:

Regarding the partial vs. saturated negation, I'm in favour of the former. However, there is another option nobody mentioned so far: NaN

NaN is only defined in the context of IEEE floating point; as such, it is not available for this use.

I'm aware of the current uses of NaN. I was just suggesting that the same concept could be used for operations on natural values that go out of band. Just like we have isNaN :: RealFloat a => a -> Bool we could add a function isUnnatural :: Natural -> Bool and replace exceptions by an unnatural Natural values... I'm open to an alternative terminology. The important question is whether this approach is feasible for the implementation.