{"ast_node_type":"variable","tokens":[{"end":62,"kind":"keyword","start":0,"text":"if"}]}
        if let Some(expr) = self.eat_metavar_seq_with_matcher(
    pub fn parse_literal_maybe_minus(&mut self) -> PResult<'a, P<Expr>> {
            |mv_kind| matches!(mv_kind, MetaVarKind::Expr { .. }),