const actionsIterator = {
  [Symbol.iterator]() {
    const steps = this.actions.slice()

    return {
      [Symbol.iterator]() {
        return this
      },
      next(...args) {
        if (steps.length > 0) {
          let result = steps.shift()(...args)
          return { value: result, done: false }
        } else {
          return { done: true }
        }
      },
      return(v) {
        steps.length = 0
        return { value: v, done: true }
      },
    }
  },
  actions: [],
}

// Usage
actionsIterator.actions = [(num) => console.log(num * num)]
const useTask = actionsIterator[Symbol.iterator]()
useTask.next(19)