[Haskell-cafe] Natural Numbers: Best implementation?
g9ks157k at acme.softbase.org
Fri Mar 13 04:25:48 EDT 2009
Am Freitag, 13. März 2009 04:53 schrieb Brandon S. Allbery KF8NH:
> On 2009 Mar 12, at 22:54, Mark Spezzano wrote:
> > I was wondering what the best way to implement Natural number would
> > be. Is there a package which already does this?
> type-level on Hackage.
I think, the original poster wanted value-level naturals, not type-level
> > 2. Use the type
> > data Natural = Zero | Succ !Natural
> One of the reasons people use type-level naturals is to get laziness;
> you've made this strict. Is there a reason?
Do you really mean type-level naturals? The following is a definition of
data Natural = Zero | Succ Natural
Type-level naturals would be defined like this:
data Succ nat
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