how to make contract for a non-empty hashtable

Question

Racket has a non-empty-listof contract but no non-empty-hashof contract. Is there a way to build one?

Answer 1

Predicates can be used as contracts, so:

(define (non-empty-hash? x)
  (and (hash? x)
       (not (hash-empty? x))))

Then you can use non-empty-hash? as your contract.