Zip multiple arrays (of equal length) using Symbol.iterator

zip2.js

function zip(...arrs) {
  let i = -1;
  return {
    [Symbol.iterator]() {
      return this;
    },
    next: () => ({
      done: ++i === arrs[0].length,
      value: arrs.map(arr => arr[i])
    })
  }
}