Recursion schemes are the FP way of doing the Visitor Pattern. You can get annotations with (coelgot, zygo) which are super useful for tupecheckers, allow the

Recursion schemes are the FP way of doing the Visitor Pattern. You can get annotations with (coelgot, zygo) which are super useful for tupecheckers, allow the fold to accumulate effects (gana, gcata), or even look into the future of the recursion (futu). They do get a bit much at times though, since you can compose them easily. Zygohistoprepromorphisms are one example of this.