Closed coot closed 5 years ago
This is essentially http://hackage.haskell.org/package/lattices-1.7.1.1/docs/Algebra-Lattice-Lifted.html, isn't it?
I'm not keen in favoring Lifted
over Dropped
, so Maybe
is better staying without an instance. (Similar reasoning why Int
doesn't have Monoid
instance).
I'd accept a PR with functions helping conversion between Lifted a <-> Maybe a <-> Dropped a
thought.
Yes, indeed; fair point. What about adding:
drop :: b -> (Dropped a -> b) -> Dropped a -> b
and
lift :: b -> (Lifted a-> b) -> Lifted a -> b
similar to maybe
.