Lazy generation of Hamming numbers in PLT Racket

hamming.ss

(define (hamming)
  (lcons 1 (lfoldr merge (map (lambda (p) (map (lambda (x) (* p x)) (hamming)))
                              (lazy-list 2 3 5)))))

; lazy-list library
(define-syntax lcons 
  (syntax-rules () 
    ((_ a b) (lambda (f) (f a (lambda () b))))))
(define (lazy-list . x)
  (foldr (lambda (x y) (lcons x y)) '() x))
(define (lcar l) (l (lambda (x y) x)))
(define (lcdr l) (l (lambda (x y) (y))))

; lazy-map
(define (map f l)
  (if (empty? l) '() (lcons (f (lcar l)) (map f (lcdr l)))))

; lazy-merge
(define (merge a b)
  (cond [(< (lcar a) (lcar b)) (lcons (lcar a) (merge (lcdr a) b))]
        [(= (lcar a) (lcar b)) (lcons (lcar a) (merge (lcdr a) (lcdr b)))]
        [(> (lcar a) (lcar b)) (lcons (lcar b) (merge a (lcdr b)))]))

; foldr with lazy-list support
(define (lfoldr f l)
  (if (empty? (lcdr l)) (lcar l) (f (lcar l) (lfoldr f (lcdr l)))))

(define (print n l)
  (if (zero? n) (void)
      (begin (printf "~a\n" (lcar l))
             (print (sub1 n) (lcdr l)))))

(print 62 (hamming))