ALT some rust code using the json! macro in a nested way. it reads like normal json syntax for the keys and structure but rust expressions are filling in the fields. especially happy with situations where an array's elements are just defined with .iter().map(json! { ... }) an excerpt: "threads": self.threads.iter().map(|thread| json!({ "frame_count": thread.frames.len(), "last_error_value": thread.last_error_value.map(|error| error.to_string()), "thread_name": thread.thread_name, "frames": thread.frames.iter().enumerate().map(|(idx, frame)| json!({ "frame": idx,