Re: Primes

B. Pym wrote:

(defun primes-below-limit (limit)
   (cons 2
     (loop for i from 3 by 2 below limit
         unless (loop for p in primes
                      thereis (integerp (/ i p)))
         collect i into primes
         finally (return primes))))

 
Gauche Scheme:
 
(use srfi-1)  ;; take-while
(use math.prime)
 
(define (primes-below-limit limit)
  (take-while (lambda(n) (< n limit)) *primes*))
 
(primes-below-limit 88)
  ===>
(2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83)
 

Using "is":

(define (primes-below-limit limit)
  (take-while (is < limit) *primes*))


Given:

(define is
  (case-lambda
    [(x) (lambda(y) (equal? y x))]
    [(pred x) (lambda(y) (pred y x))]
    [(key pred x) (lambda(y) (pred (key y) x))]))