;; Using lazy lists.

(load "search-for-primes-common.ss")
(load "search-for-primes-lazy.ss")

(define (timed-function-test fun)
  (let ((start-time (runtime))
        (result (fun))
        (end-time (runtime)))
    (cons result (- end-time start-time))))

(define (timed-prime-test n)
  (timed-function-test (lambda () (cons (prime? n) n))))

(define (search-for-primes how-many start)
  (define odd-numbers
    (lazy-filter odd? (infinity-starting-at start)))
  (define (decide test-result)
    (caar test-result))
  (define (get-rid-of-primality test-result)
    (cons (cdar test-result) (cdr test-result)))
  (lazy->list (lazy-map get-rid-of-primality
                        (lazy-filter decide
                                     (lazy-map timed-prime-test
                                               odd-numbers)
                                     how-many))))