Instance for Numeric.Natural

[dschrempf]

Hi! I was wondering if we could provide an orphan instance for Numeric.Natural? At the moment, I am using something naive like:

fToMemoize :: Natural -> a
fToMemoize = ...

fToMemoizeI :: Integer -> a
fToMemoizeI = fToMemoize . fromIntegral

fMemoized :: Natural -> a
fMemoized = memoize fToMemoizeI . fromIntegral

I had a look at the definition of Natural, and it is either a simple WordXX, or a big natural. The big natural is, as far as I can see, similarly built as 'Integers, and could be converted to a list (like it is done for the Memoizableinstance ofInteger`). Could you please help out here? Thank you!

[jwaldmann]

like this?

instance Memoizable Natural where
  memoize f = memoize (f . fromIntegral) . toInteger