Josef Svenningsson wrote:
Greg, you express the sequential computation of updating the set of planets as an iteration over a list. This is a sweet way of expressing it but doesn't work very well when an element of the list contain pointers to the previous element. This will force all the elements to be in memory at the same time. What causes this is too little strictness, all computations which depend on the previous element haven't been forced and thus still points to it. It this specific program the problem is the list of planets. Even if we may have computer ourselves a new list of planets the planets themselves haven't been computed yet and will contain pointers to the previous list of planets. Devastating! Hence we will need a strict list to do this or some other strict data structure.
So, here's my code. It's not beautiful but it solves the space problem. I hope I got it right this time :)
Alright, looks good. I've incorporated this latest change. You can see the code... http://xrl.us/fzn4 Greg Buchholz