; scheme ; http://xahlee.org/tree/tree.html ; Xah Lee, 2005-05 ; code by Jussi Piitulainen jpiit...@ling.helsinki.fi ;;; Increasing list of b+ks in the interval [b..e) if s > 0. ;;; Decreasing list of b+ks in the interval (e..b] if s < 0. (define (range b e s) (do ((k (- (ceiling (/ (- e b) s)) 1) (- k 1)) (r '() (cons (+ b (* k s)) r))) ((< k 0) r))) ; test (display (range 3 5 1/2)) ; Note this code is very much incorrect.