class NodeList { private readonly n: Value[]; constructor() { this.n = []; } last() { const len = this.n.length if (len > 0) { return this.n[len - 1]; } return undefined; } has() { return this.n.length > 0; } flush() { return this.n.length ? this.n.pop() : undefined; } push(value: Value) { this.n.push(value); } ref() { return this.n; } } export { NodeList }; export default NodeList;