fn emit_node<F: FnOnce(&mut Self, usize) -> R, R>(&mut self, f: F) -> R {
assert_eq!(self.lazy_state, LazyState::NoNode);
let pos = self.position();
fn emit_node<F: FnOnce(&mut Self, usize) -> R, R>(&mut self, f: F) -> R {
assert_eq!(self.lazy_state, LazyState::NoNode);
let pos = self.position();