Is there a standard sorted set/map class that gets used for ruby? Something like a btree, red-black tree etc; it doesn't really matter what it does since I assume any sensible implementation would use Enumerable and look a lot like an array externally. As far as I can tell the libraries that come with ruby have no such thing, but if I'ved missed it many apologies. A google search did turn up a few such things and I suppose I can just pick one, but it seems like something that might be commonly needed (and therefore have a commonly used implementation). I couldn't find anything relevent on this list's archives but maybe I didn't try hard enough. -kyle -- http://mas.cs.umass.edu/~rawlins -- What a world of solemn thought their monody compels!