an implementation of iterate

iterate.rkt

#lang racket

;; inspired by http://zvon.org/other/haskell/Outputprelude/iterate_f.html

(define (iterate f acc)
  (make-do-sequence
   (lambda ()
     (values
      (lambda (x) x)
      (lambda (x) (f x))
      acc
      #f
      #f
      #f))))

(define doubles (iterate (lambda (x) (* 2 x)) 1))

(for/list ([x doubles]
           [n (in-range 10)])
  x)