this is a pretty hand wavy introduction to zippers. A Zipper is many cool things, but most importantly it can be thought of as a really nice way of supporting

this is a pretty hand wavy introduction to zippers. A Zipper is many cool things, but most importantly it can be thought of as a really nice way of supporting arbitrary traversals of tree-like data structures. On the theory side there are cool papers such as www.cs.nott.ac.uk/~ctm/diff.pdf which talk about some of the interesting relationships between zippers and certain types of recursive data structures. Also, earlier this summer someone released a really wonderful generic zipper library for haskell https://www.cs.indiana.edu/~adamsmd/papers/scrap_your_zippers/ https://www.cs.indiana.edu/~adamsmd/papers/scrap_your_zipper... that is quite nice. I've actually spent a few weeks this summer thinking very hard about how to add some cool functionality to the zipper abstraction layered on top of the scrap your zipper library. Either way, if you're doing anything algorithmic on a tree that is more complicated than a left or right fold, if you're not using a zipper, you're probably making things overly difficult for you self. Save a programmer (week), use a zipper! :)