[_dwt]

I think lenses/optics have stolen some of zippers' (very localized) thunder in recent years, but I still enjoy finding excuses to use them every once in a while. (OK, so really just a couple Advent of Code problems.)

I have never actually had the wherewithal to go through the whole automatic-derivation-of-zippers thing, but this (https://stackoverflow.com/questions/25554062/zipper-comonads...) StackOverflow Q&A (along with all of Conor McBride's SO answers - compiled at https://personal.cis.strath.ac.uk/conor.mcbride/so-pigworker...) might be of interest in conjunction with the linked paper.