paul graham wrote:

> Or you could write
>
> (defun pos+ (lst)
> (let ((i -1))
> (mapcar #'(lambda (x) (+ x (incf i)))
> lst)))
>
> Btw, in Arc that would be
>
> (def pos+ (lst)
> (let i -1
> (map [+ _ (++ i)] lst)))

It's better in Gauche Scheme.

(define (pos+ lst)
(map + lst (lrange 0)))

(pos+ '(200 300 400 500))
===>
(200 301 402 503)

Another way:

(use gauche.sequence) ;; map-with-index

(define (pos+ lst)
(map-with-index + lst))

(pos+ '(200 300 400 500))
===>
(200 301 402 503)

On 2/25/2022, Robert L. wrote:

> It's better in Gauche Scheme.
>
> (define (pos+ lst)
> (map + lst (lrange 0)))
>
> (pos+ '(200 300 400 500))
> ===>
> (200 301 402 503)

Shorter:

(define (pos+ lst)
(map + lst (liota)))