Integer to hex code - scheme lang

convert-int-hex.scm

(define remainder-to-hex ; val: string
  (lambda (n) ; n: integer 0 <= n <= 16
    (let ((str-offset (lambda (k) (int->string (+ n k)))))
      (cond ((< n 10) (str-offset 48))
            ((> n 9) (str-offset 55))
            (else "NOTVALID")
      )
    )
  )
)

(define convert-int-hex-unwrapped ; val: string
  (lambda (n) ; n: integer
   (let ((q (/ n 16)) (r (remainder n 16)))
    (if (= q 0)
        ""
        (string-append
          (convert-int-hex-unwrapped (floor q))
          (remainder-to-hex r)
        )
    )
   )
  )
)

; wrapping to cover the 0 case without messing the result
(define convert-int-hex ; val: string
  (lambda (n) ; n: integer
    (if (= n 0)
        "0"
        (convert-int-hex-unwrapped n)
    )
  )
)

(convert-int-hex 123) ; => "7B"

Fixed 0 case, using floor instead of round.

Fixed 0 case with a wrap, preferred way since it doesn't add a 0 in front of the result.