Ring data structrure in JavaScript.

ring.js

class Ring {
    constructor(...data) {
        this.position = 0;
        if (data instanceof Array) {
            this.data = data[0];
            return;
        }

        this.data = data;
    }

    value() {
        return this.data[this.position];
    }

    toArray() {
        return this.data;
    }

    length() {
        return this.data.length;
    }

    index() {
        return this.position;
    }

    next() {
        let pos = this.position + 1;
        if (!this.data[pos]) {
            pos = 0;
        }
        
        this.position = pos;

        return this;
    }

    prev() {
        let pos = this.position - 1;
        if (!this.data[pos]) {
            pos = this.data.length - 1;
        }

        this.position = pos;

        return this;
    }

    pop() {
        this.data.splice(this.position, 1);

        return this;
    }

    push(data) {
        this.data.splice(this.position, 0, data);

        return this;
    }
}