[Haskell-cafe] Circular pure data structures?

Antoine Latter aslatter at gmail.com
Wed Jul 15 01:19:38 EDT 2009

On Wed, Jul 15, 2009 at 12:13 AM, Eugene Kirpichov<ekirpichov at gmail.com> wrote:
> Zippers come up as the "derivative" of the type; if you haven't yet
> encountered this trick, then first find it :)
> Try differentiating your datastructure.

Here's a paper with a good introduction to the concept and bibliography:


My take on it:

A zipper is the one-hole-context of your data-type plus a focused-on
payload. Data-structure differentiation is the method for deriving the


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