Hi,

I was learning about 'shrink' lately and I was trying to create some instances. It felt quite awkward until I realized that the operation for producing shrunk tuples is an applicative functor. I was playing with the idea for a while and I'm sending an experimental  patch against QuickCheck master that shows the basics of the idea and how it can help constructing  'shrink' instances. If you feel that this is a good idea, let me know, I'll work on a full patch.

  Best regards,
  Petr