Kent M. Pitman wrote:

> > > Even non-programmers know
> > > what it means to say "For every setting at the table, make sure the
> > > napkin is arranged right".
>
> > This can be expressed functionally in Scheme using map (like mapcar in CL).
> > It's not necessary to use iteration.
>
> But MAP is not good for expressing "For every number from 0 to 9, make sure
> it appears on the phone dial" because Scheme does not provide an object
> over which one can "map" numeric ranges, as CL's LOOP does.

Gauche Scheme:

(define phone-dial '(0 1 2 3 4 5 6 7 8 9))

(every (cut member <> phone-dial) (iota 10))
===>
(9)

(every (cut member <> phone-dial) '(2 6 8 22))
===>
#f

(find (lambda(x) (not (member x phone-dial))) '(2 6 8 22))
===>
22

(use srfi-1)

(lset-difference = '(2 6 8 22) phone-dial)
===>
(22)