circular-list.js

// source: https://stackoverflow.com/questions/71608818/purely-functional-immutable-doubly-linked-list-in-javascript
var head = (function CircularList(previous, item, ...items) {
    if (!items.length) return { item, next: () => head, previous };
    var rest = CircularList(() => current, ...items); // Recursion
    var current = { ...rest, previous };
    return { ...rest, item, next: () => current };
})(() => head, 1, 2, 3, 4);