[MWForum]curious language

[Daniel Ajoy]

On 16 Mar 2005 at 11:18, jbonnes@libertyschool.us wrote:

> Thanks Everyone,
> I also just learned that Logo programs can call themselves, Seymour Papert just
> gave me this program and now I'm trying to understand it.
> to el :x :n
> ifelse :n = 0 [fd :x]
> repeat 4 [ el :x / 3 (:n-1) rt 90]]
> end
> It doesn't do what I want it to, but to me this is intriguing because coming
> from C a program can't call itself. 

Not so:

http://www.funducode.com/freec/Recursion/recursion1.htm

> I'v been trying to figure what's going on.
> The program draws a square and then fills it up with four more squares, if you
> input :n as 2. How does the program stop.

Isn't there a missing bracket?

to el :x :n
ifelse :n = 0 [fd :x] [repeat 4 [ el :x / 3 (:n-1) rt 90]]
end

If n is 0 the programs stops. 

n will eventually be 0 because each time "el" is
called the value "el" receives as input is decreased
by 1

Daniel
OpenWorld Learning