{"ast_node_type":"variable","tokens":[{"end":95,"kind":"keyword","start":0,"text":"let"}]}
        let step = rest.iter().position(|&(_, _, c)| !c.is_whitespace()).unwrap_or(rest.len());
        let rest = &self.input_vec[self.input_vec_index..];
        self.input_vec_index += step;