ContainerField

    pub const ContainerField = struct {
        comptime_token: ?TokenIndex,
        ast: Components,

        pub const Components = struct {
            main_token: TokenIndex,
            /// Can only be `.none` after calling `convertToNonTupleLike`.
            type_expr: Node.OptionalIndex,
            align_expr: Node.OptionalIndex,
            value_expr: Node.OptionalIndex,
            tuple_like: bool,
        };

        pub fn firstToken(cf: ContainerField) TokenIndex {
            return cf.comptime_token orelse cf.ast.main_token;
        }

        pub fn convertToNonTupleLike(cf: *ContainerField, tree: *const Ast) void {
            if (!cf.ast.tuple_like) return;
            if (tree.nodeTag(cf.ast.type_expr.unwrap().?) != .identifier) return;

            cf.ast.type_expr = .none;
            cf.ast.tuple_like = false;
        }
    }