fibs.scm

(define (each-fib fn)
  (letrec
    ((next (lambda (a b)
             (fn a)
             (next b (+ a b)))))
    (next 0 1)))

(define (take-n-fibs n)
  (call/cc
    (lambda (return)
      (let*
        ((lst '())
         (fn (lambda (v)
               (set! lst (cons v lst))
               (set! n (- n 1))
               (if (= 0 n) (return (reverse lst))))))
        (each-fib fn)))))