One of the things I still can;t wrap my head around is if (filter positive? (map sub1 '(1 2 3))) involves two full list traversals or one lazy one. If it involves two then is there a more efficient way of doing this?

@mark.warren that does two list traversals

to do only one, see filter-map or use (for*/list ([i '(1 2 3)] [v (in-value (sub1 i)] #:when (positive? v)) v)

@samth Thanks, that was what I thought, I’ll look into those alternatives.

With big-bang, does the to-draw handler have to complete before the next tick? I am having strange issues with drawing if I go over a certain number of items to draw.

@mark.warren yes, i believe so

Ah, I might be better off using a canvas then and handling the refresh myself.

@samth Thanks again.