;; First try

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


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

(define (cut-precision inexact digits)
  (define factor (expt 10 digits))
  (/ (round (* inexact factor)) factor))

(define (report-prime n elapsed-time)
  (begin
    (display n)
    (display ": ")
    (display (cut-precision elapsed-time 4))
    (newline)))

(define (display-timed-primes prime-results)
  (if (not (null? prime-results))
      (letrec ((first-result (car prime-results))
               (prime (car first-result))
               (elapsed-time (cdr first-result)))
        (begin
          (report-prime prime elapsed-time)
          (display-timed-primes (cdr prime-results))))))

(define (search-for-3-primes start)
  (search-for-primes 3 start))

;;;

(define (search-for-primes how-many start)
  (define (_search-for-primes how-many start results)
    (if (= how-many 0)
        (reverse results)
        (let-values (((primality elapsed-time) (timed-prime-test start)))
          (_search-for-primes (if primality
                                  (- how-many 1)
                                  how-many)
                              (+ start 2)
                              (if primality
                                  (cons (cons start elapsed-time) results)
                                  results)))))
  (_search-for-primes how-many
                      (if (even? start)
                          (+ start 1)
                          start)
                      '()))