Re: [Chicken-users] nested loop over lists

[Jinsong Liang]

Wow, this is amazing! Thanks a lot Christian!

Jinsong

On Thu, Jul 14, 2016 at 3:05 AM, Christian Kellermann <address@hidden> wrote:

* Jinsong Liang <address@hidden> [160714 04:26]:
> Hi,
>
> I want to do nested loops over three lists like the following pseudo code:
>
> for i in '(1 2 3)
>     for j in '(4 5 6)
>         for k in '(7 8 9)
>           //do calculation using i, j, and k. The three lists are not
> related.
>         end
>     end
> end
>
> What is the best way to do this in Chicken? I can use (for-each ...) or (do
> ...) but it seems neither is straightforward.

Without knowing the purpose of this it's hard to say.  However scheme
is flexible enough to allow an almost verbatim translation using
foof-loop:

(use foof-loop)

(loop ((for i (in-list '(1 2 3))))
      (loop ((for j (in-list '(4 5 6))))
                  (loop ((for k (in-list '(7 8 9))))
                                    (print "Magic " i "+" j "+" k " = " (+ i j k)))))

HTH,

Christian

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