#lang typed/racket

;; No `cast` or `inst` needed.

(: functional (-> (U (-> Symbol Boolean)
                     (-> Symbol Char))
                  (-> Symbol String)))

(define (functional prc)
  (lambda (smb)
    (let ((obj (prc smb)))
      (cond ((boolean? obj)
             (if obj "1" "0"))
            ((char? obj)
             (string obj))))))

;; Both `cast` and `inst` needed.

(: hashish (-> (U (HashTable Symbol Boolean)
                  (HashTable Symbol Char))
               (HashTable Symbol String)))

(define (hashish hsh)
  ((inst hash-map/copy Symbol (U Boolean Char) Symbol String)
   (cast hsh (HashTable Symbol (U Boolean Char)))
   (lambda (smb obj)
     (cond ((boolean? obj)
            (values smb (if obj "1" "0")))
           ((char? obj)
            (values smb (string obj)))))))