Thank you though, what you've written here is very useful -- you're describing things I'm immediately recognising in what I'm doing. As I say, it's just a small

Thank you though, what you've written here is very useful -- you're describing things I'm immediately recognising in what I'm doing. As I say, it's just a small toy (and I think one that would definitely be easier in a different language, but anyway...). At the minute I'm actually at the point where I'm preallocating and persisting a set of internal objects, and at a very very small scale it's ok, but each exploration in structure starts to become manageable pretty quickly.