Experiments with writing range functions in Scheme.

range.scm

; Uses Berkeley's (sentence) helper - slow after 1-5k, but supports larger range than `range-se-recur`
(define (range-se-iter start end)
  (define (iter c ret)
    (if (= c end)
      ret
      (iter (+ c 1) (se ret c))))
  (iter start '()))

; Uses Berkeley's (sentence) helper - quite slow after 1-5k, seg faults around 1-15k
(define (range-se-recur start end)
  (if (= start end)
    '()
    (se start (range-se-recur (+ start 1) end))))

; Fast
; ~300 ms for 1-100k
; ~4s for 1-1M
(define (range-iter start end)
  (define (iter c ret)
    (if (< c start)
      ret
      (iter (- c 1) (cons c ret))))
  (iter (- end 1) '()))

; Fast but segfaults around 1-22k
(define (range-recur start end)
  (if (= start end)
    '()
    (cons start (range-recur (+ start 1) end))))