$href = {
    value => "some data",
    next  => {
        value => "more data",
        next => {
            value => "still more",
            next => undef
        },
    },
};

##</code><code>##

$aref = [
    "some data",
    [
        "more data",
        [
            "still more",
            undef
        ],
    ],
];