Simple LRU implementation in Scheme

lru.scm

(define (make-lru size)
  (define cnt 0)
  (define fl '())
  (define ht (make-hash-table))
  (define (refresh-fl i)
    (set! fl (cons i (filter (lambda (x) (not (= x i))) fl))))
  (lambda (cmd . i/v)
    (case cmd
      ((get)
       (refresh-fl (car i/v))
       (hash-ref ht (car i/v) "no"))
      ((set)
       (display fl) (newline)
       (if (= cnt size)
           (let ((i (list-ref fl (1- cnt))))
             (hash-set! ht i (car i/v))
             (refresh-fl i))
           (begin
             (set! fl (cons cnt fl))
             (hash-set! ht cnt (car i/v))
             (set! cnt (1+ cnt))))
       (hash-map->list cons ht))
      ((cnt) cnt)
      ((fl) fl))))