purely functional carousel for JavaScript Arrays

carousel.js

// is this possible with a purely-functional doubly-linked list in JavaScript?
function carousel(items) {
    return {
        _fastForward: function(n) {
            if (n === 0) return carousel(items)
            else return carousel([].concat(items.slice(1), items[0]))._fastForward(n - 1)
        },
        _rewind: function (n) {
            if (n === 0) return carousel(items);
            else return carousel([].concat(items[items.length - 1], items.slice(0, items.length - 1)))._rewind(n - 1);
        },
        previous: function (n) {
            return function (results) {
                if (n === 0) return [results.reverse(), Object.assign({}, carousel(items), {
                    next: function(n) {
                        return carousel(items)._fastForward(n).next(n)
                    }
                })];
                else return carousel(items)._rewind(1).previous(n - 1)([].concat(results, items[items.length - 1]));
            };
        },
        next: function (n) {
            return function (results) {
                if (n === 0) return [results, Object.assign({}, carousel(items), {
                    previous: function(n) {
                        return carousel(items)._rewind(n).previous(n)
                    }
                })]
                else return carousel(items)._fastForward(1).next(n - 1)([].concat(results, items[0]));
            };
        }
    }
};