Re^2: Re-orderable keyed access structure?

[BrowserUk]

Could you elaborate this a bit?

If I have an array of indices to the positions of the items in another array. When one of the items moves from the middle to the begining or end of it's array, all the indices for the items between it's old position and the end to which it has moved change. I'm not sure what that buys me?

I think if I could get (readonly) references to the hash keys, not just the hash values it might allow bi-directional indirection. But I don't know how to do that.