Excellent time to mention rust's `ControlFlow` enum which allows doing this exact sort of thing https://doc.rust-lang.org/std/ops/enum.ControlFlow.html https://

Excellent time to mention rust's `ControlFlow` enum which allows doing this exact sort of thing https://doc.rust-lang.org/std/ops/enum.ControlFlow.html https://doc.rust-lang.org/std/ops/enum.ControlFlow.html Not as ergonomic as a direct tree-iterator, but I can't see of an elegant way to introduce that in an imperative language while keeping the forking/recursion aspect clear