@ecstatic-morse I agree with that critique *as well*. :) I think [SYB](https://www.microsoft.com/en-us/research/wp-content/uploads/2003/01/hmap.pdf) in the style of [lens](https://hackage.haskell.org/package/lens-4.15.1/docs/Control-Lens-Plated.html) is neater for that reason, but we don't have generic closures unfortunately.