consumable-array.mjs

array-like.mjs

const {
  defineProperties,
  getOwnPropertyDescriptors
} = Object;

/**
 *   A root Array-like "class" compatible with both es5 and es6 styles
 */
export function ArrayLike() {
  if (!(this instanceof ArrayLike)) {
    // "callable-constructor" why not?
    return new ArrayLike(...arguments);
  }

  Array.apply(this, arguments);
}

defineProperties(
  ArrayLike.prototype,
  getOwnPropertyDescriptors(Array.prototype)
);

export default ArrayLike;

consumable-array.mjs

import ArrayLike from "./array-like.mjs";

/**
 *   Basic idea: iteration is consumption
 */
export class ConsumableArray extends ArrayLike {
  [Symbol.iterator]() {
    return this;
  }

  next() {
    return this;
  }

  get value() {
    return this.shift();
  }

  get done() {
    return !this.length;
  }
}

export default ConsumableArray;

self-populating-list.mjs

import ConsumableArray from "./consumable-array.mjs";

/**
 *   Demonstration: Will maintain a list of 10 items
 */
export class SelfPopulatingList extends ConsumableArray {
  constructor() {
    super(...arguments);

    let count = 0;

    const tick = ()=> {
      if (this.length < 10) {
        this.push({ id: count++ });
      }

      setTimeout(tick, 1000);
    };

    setTimeout(tick);
  }
}