On Sat, Mar 13, 2010 at 3:55 PM, Jerome David Sallinger <imran.nazir / yahoo.co.uk> wrote: > Thank you for all the ideas peeps. Much appreciated, I was hoping that > there was some way to avoid iterators/loops such that a 'Ball' object > would be aware of its locatation in, for simplicities sake, '2D' space > and weather it shares it with anything else. If not then that cool but > maybe there is some undiscovered territory concept wise for me to > explore. I'd suggest looking at the Observer pattern. Have each Ball continuously register its location (x,y) with a single Observer object; an attempt to register to an occupied location can be handled however you want -- throw an exception, send the Ball a message to reverse direction, vaporize the Ball, etc. No loops or iterators in sight :-) FWIW, -- Hassan Schroeder ------------------------ hassan.schroeder / gmail.com twitter: @hassan