In Haskell, I have a module with a partial order type:
data PartialOrder a = PartialOrder [a] [(a, a)]
I don't export the value constructor because that's not how I want the type to be used, but I still want to be able to pattern match the PartialOrder type outside the module; is this possible? In particular, I want to be able to pattern match something that is not the type constructor, but instead, to pattern match something like the following:
f (PartialOrder xs le) = ...
Where le is a function implicitly defining the explicit ordering defined in the value constructor. I know such a facility is available in Scala, is there a way to do the same in Haskell?
Thanks in advance.