positive type-level naturals

[Henning Thielemann]

Am 16.03.2014 20:02, schrieb Carter Schonwald:
> respectfully,
> The current typeLits story for nats is kinda a fuster cluck to put it
> politely . We have type lits but we cant use them (well, we can't
> compute on them, which is the same thing).
>
> For the past 2 years, every ghc release cycle, I first discover, then
> have to communicate to everyone else "you can't compute on type lits".

A minimal invasive solution would be to provide a kind for unary type 
level numbers and type functions that convert between Unary and Nat.