> I know it is possible, but I'm not sure aboout how to write the following
> with a functional approach:
>
> > (loop for i from 1 to 10 collect (loop for j from 1 to i collect j))
> ((1) (1 2) (1 2 3) (1 2 3 4) (1 2 3 4 5) (1 2 3 4 5 6) (1 2 3 4 5 6 7) (1 2
> 3 4 5 6 7 8) (1 2 3 4 5 6 7 8 9) (1 2 3 4 5 6 7 8 9 10))

Gauche Scheme:

(define (rng low high func)
(if (> low high)
'()
(cons (func low) (rng (+ 1 low) high func))))

(rng 1 10 (cut rng 1 <> values))

===>
((1) (1 2) (1 2 3) (1 2 3 4) (1 2 3 4 5) (1 2 3 4 5 6) (1 2 3 4 5 6 7)
(1 2 3 4 5 6 7 8) (1 2 3 4 5 6 7 8 9) (1 2 3 4 5 6 7 8 9 10))