It isn't hard to make a datastructure that indexes into itself. BDDs, for example, are often coded in this way. I did an admittedly poor job of one at https:/

It isn't hard to make a datastructure that indexes into itself. BDDs, for example, are often coded in this way. I did an admittedly poor job of one at https://taeric.github.io/trading-with-bdds.html https://taeric.github.io/trading-with-bdds.html, but I think it is enough to see the idea well enough.