trouble with negative numbers?

[jywarren]

I'm not sure I have this right, but I think it this could be choking on negatives (adapted from http://www.logointerpreter.com/view-program.php?user=spaulc90&program=generate_dragon_fractal):

; generates the actual fractal recursively

to dragon_fractal :size :dir
    if :size < 3 [fw :size]
    right 45*:dir
    dragon_fractal :size*(sqrt 2)/2 1
    left 90*:dir
    dragon_fractal :size*(sqrt 2)/2 -1
    right 45*:dir
end

setxy -50 -135

; Initial value 320 gives a nicely centered dragon
; I don't recommend going over 400 or the browser might crash
; (and the dragon will be aout of view)

dragon_fractal 320 1

[jywarren]

Ug, I think I solved the negatives issue, but this still won't run due to too much recursion. I'm a little out of my depth, but was reading about tail recursion here; i wonder if there's some optimization such as discussed here that would allow this. Perhaps logointerpreter.com has implemented this.

http://compgroups.net/comp.lang.logo/-logoforum-tail-recursion/325587