Not very comparable. TLA+ involves writing statements in a custom "logic" which adds modalities (i.e. monads) to support 'time' (or rather, state transitions in discrete steps, ala temporal logic) and non-determinism (which is reused to support refinement) to standard propositional logic.

Nothing like this can be done in a standard programming language (even Scala or Haskell), and even in a dependently-typed language you would need to write some support code in order to embed this logic and work with it within the system. (It wouldn't be hard for sure, since even FOL gives you far more power than any (multi-)modal logic, but it's a different, perhaps more elegant take on things than just working directly within TLA).