Skip Lists: https://docs.racket-lang.org/data/skip-list.html https://docs.racket-lang.org/data/skip-list.html These functional red/black-trees have `map` and

Skip Lists: https://docs.racket-lang.org/data/skip-list.html https://docs.racket-lang.org/data/skip-list.html These functional red/black-trees have `map` and `filter`: https://docs.racket-lang.org/functional-data-structures/Red-Black_Trees.html https://docs.racket-lang.org/functional-data-structures/Red-... AVL-trees: https://docs.racket-lang.org/avl/index.html https://docs.racket-lang.org/avl/index.html I would be surprised if someone hasn't made a B-tree implementation already. As bonus: Another red/black-tree implementation (imperative): https://github.com/soegaard/little-helper/blob/master/planet/galore.plt/2/2/private/raw-red-black-tree-set.scm https://github.com/soegaard/little-helper/blob/master/planet...