> I had trouble expressing cyclic data structures You cannot do cyclic data structures in Rust because every thing must have one owner, so no cycles. You can

> I had trouble expressing cyclic data structures You cannot do cyclic data structures in Rust because every thing must have one owner, so no cycles. You can do cyclic data structures in Rust with unsafe code or doing your own memory management (e.g. an arena data structure). > The borrow checker worked fine when all I needed to do was pass data up and down the callstack, but anything beyond that was difficult or impossible to express That is not true. It is true at the start of the learning curve, but you get used to it. Cyclic data structures are very far from simple.