No way to retrieve the base of a Set or Map in O(1)

[André van Delden]

Hello,


> do you have any use-case where such function is useful?

I am trying to generalize some combinatorial functions to a class of
types containing any sort of element. For many combinatorial functions
it is useful to split the elements at some element and recombine them
after a recursion over the parts. That's what I was thinking of.

But others seem to be interested aswell (although it is a beginner
asking, so there might be a better solution to his problem):

http://osdir.com/ml/beginners@haskell.org/2015-03/msg00091.html

Kind regards,
André