/**
 * I like how languages such as Ruby and Python make it easy to iterate over
 * their respective number primitives, e.g. the "Rails way":
 *
 * 10.times do |x|
 *   doSomething(x)
 * end
 *
 * In short, the above code is ~elegant~ in that when read in english, it's
 * pretty straightforward compared to a for loop. It's also
 * elegant in the regard that it's simplistic and concise.
 *
 * I think Javascript should have these kinds constructs. To that end, this is more
 * of an exercise of how we can use this kind of elegant feature.
 */

Number.prototype[Symbol.iterator] = function() {
  let current = 0
  return {
    next: () => {
      const increment = this > 0 ? 1 : -1
      return {
        done: current == this,
        value: current += increment
      }
    }
  }
}

// now we can do a multiply function without the * or / operators using a similar construct
function multiply(a, b) {
  return [...a].reduce(agg => a < 0 ? agg - b : agg + b, 0)
}

console.log(multiply(10, 10)) // 100
console.log(multiply(123, 0)) // 0
console.log(multiply(3, 5)) // 15
console.log(multiply(5, 3)) // 15
console.log(multiply(-4, 5)) // -20
console.log(multiply(4, -4)) // -16
console.log(multiply(-7, -7)) // 49