Create ordinal numbers

Generator.js

class Store {
  // Ordinal numbers sequence.
  ordinal = null

  // Ordinal numbers generator.
  ordinalGenerator = function * () {
    let i = 0
    while (true) {
      yield i++
    }
  }

  constructor () {
    // Initialize ordinal generator sequence.
    this.ordinal = this.ordinalGenerator()

    this.ordinal.next().value
  }
}