Artyom Bologov, 2024-07-15 01:05 +0400:
> I'm looking for ways to type-check and otherwise validate the data that
> my functions get.

I'm new to lisps, so take this only as a source of inspiration for your
work. Racket's contracts have been already mentioned here. Another prior
art case study is Clojure's spec library:
-   https://clojure.org/guides/spec
-   "Maybe Not - Rich Hickey",
    https://www.youtube.com/watch?v=YR5WdGrpoug