^: is induction, not recursion. You should use either $: or a named
routine if you want recursion.
Also, ^: is defined such that the left argument is constant and the
right argument is the result of the previous function evaluation. (Or,
initially, the initial right argument.)
Still, you can sort of do what you are asking for by including the
left argument with the right argument. Though, of course, if you do
that, you'll need to pick out just the right argument from your final
result. Like this, for example:
{: (>:@{., +/)^:(3)2 2
That gives you:
(>:@{., +/) 2 2
3 4
(>:@{., +/) 3 4
4 7
(>:@{., +/) 4 7
5 11
{: 5 11
11
I hope that makes sense,
--
Raul
On Tue, Sep 27, 2016 at 3:35 AM, Skip Cave <[email protected]> wrote:
> NB. I am attempting to learn recursion using ^:
>
>
> NB. A simple recursion:
>
>
> 2+^:(3) 2
>
> 8
>
>
> NB. This is equivalent to
>
>
> 2+2+2+2
>
> 8
>
>
> NB. What if I want to change the left argument on each recursion?
>
> NB. Instead of 2 each time, I want to add 2, then 3, then 4.
>
> NB. I know there are much easier ways to do this, but I want to see
>
> NB. if I can avoid do. while. loops if the left argument changes on each
> iteration
>
>
> NB. I tried
>
>
> (2 3 4)+^:(3) 2
>
> 8 11 14
>
>
> NB. Nope. That didn't work.
>
> NB. What I want to achieve is:
>
>
> 2+3+4+2
>
> 11
>
> NB. but do it recursively using ^:
>
> Skip
>
> Skip Cave
> Cave Consulting LLC
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