;; - Function: unfold p f g seed &optional tail-gen
;;      [SRFI-1] Fundamental recursive list constructor.  Defined by the
;;      following recursion.
;;
;;           (unfold p f g seed tail-gen) ==
;;              (if (p seed)
;;                  (tail-gen seed)
;;                  (cons (f seed)
;;                        (unfold p f g (g seed))))
;;      That is, P determines where to stop, G is used to generate
;;      successive seed value from the current seed value, and F is used
;;      to map each seed value to a list element.

(use srfi-1)

(define (add1 n)
  (+ n 1))

(define (natural-numbers-to n)
  (unfold (cut = <> n)
          identity
          add1 0))

(define (make-adders n)
  (unfold (cut = <> n) (lambda (i) (cut + <> i)) add1 0))

;; haskell
;; makeAdders n = map (+) [1..n]
;; or in Scheme (using the fairly common "curry" and srfi-1's "iota"):
(define (make-adders n)
  (map (curry +) (iota n 1)))

(print (unfold
        (lambda (value)                 ; stop condition
          (> value 10))
        (lambda (value)                 ; mapping function
          (* value value))
        (lambda (value)                 ; next value generator
          (+ value 1))
        0                               ; start value
        (lambda (value)                 ; finaliser
          ())))