Are there non-trivial Foldable or Traversable instances that don't look like containers?

Question

There are lots of functors that look like containers (lists, sequences, maps, etc.), and many others that don\'t (state transformers, IO, parsers, etc.). I\'ve

Answer 1

I don’t think it’s actually Foldable or Traversible, but MonadRandom is an example of something that could be, functioning like an infinite list, but which doesn't look any more like a container than anything else that’s foldable. Conceptually, it’s a random variable.