Comment by Jeaye

Rich has many great ideas and he founded Clojure. I respect him deeply. On typing, however, we do not agree entirely.

For a practical example of a Clojure-like language with a completely static type system (with affine typing), see Carp. https://github.com/carp-lang/Carp

I don't see why there can't be a Carp mode in jank, with bridges in place to connect the Clojurey world from the Carpy world. This would allow jank users to develop interactively to start with, figure out their shapes, use the REPL, etc. Then, if they want, they can lock down some parts of the code for both performance and correctness gains.