How well do zippers perform in practice, and when should they be used?
- by Rob
I think that the zipper is a beautiful idea; it elegantly provides a way to walk a list or tree and make what appear to be local updates in a functional way.
Asymptotically, the costs appear to be reasonable. But traversing the data structure requires memory allocation at each iteration, where a normal list or tree traversal is just pointer chasing. This seems expensive (please correct me if I am wrong).
Are the costs prohibitive? And what under what circumstances would it be reasonable to use a zipper?
