----- Original Message ----- From: "Massimiliano Mirra" <list / NOSPAMchromatic-harp.com.web-hosting.com> To: "ruby-talk ML" <ruby-talk / ruby-lang.org> Sent: Saturday, August 03, 2002 8:38 PM Subject: Re: Assoc Class (Hash Pairs) > You are thinking in terms of bidirectional links between objects. > Take a look at the ZigZag concept, you'll find lots of food for > thought. :-) OK, Massimiliano, now you've done it -- you've mentioned ZigZag! I've read about it, though I'm still trying to assimilate it. It sounds like it's just a specialized form of a directed graph with a few constraints on it. Or is ZigZag the app itself? I thought it was a kind of data structure... Are there good practical uses for it, and has anyone here done anything with it (especially in Ruby)? Hal