syntax_data: {"ast_node_type":"other","tokens":[{"end":92,"kind":"keyword","start":0,"text":"(Self::Alt(alts),"}]}
source_snippet:             (Self::Alt(alts), other) | (other, Self::Alt(alts)) if alts.len() == 0 => other,
context_before:         match (self, other) {
context_after:             (Self::Alt(mut lhs), Self::Alt(rhs)) => {