Easier way to iterate over generator? [duplicate]

Question

Is there an easier way (than the one I am using) to iterate over a generator? Some sort of best practice pattern or common wrapper?

In C# I'd usually have something as simple as:

public class Program {
    private static IEnumerable<int> numbers(int max) {
        int n = 0;
        while (n < max) {
            yield return n++;
        }
    }

    public static void Main() {
        foreach (var n in numbers(10)) {
            Console.WriteLine(n);
        }
    }
}

Trying the same in JavaScript this is the best I could come up with:

function* numbers(max) {
  var n = 0;
  while (n < max) {
    yield n++;
  }
}

var n;
var numbers = numbers(10);
while (!(n = numbers.next()).done) {
  console.log(n.value);
}

Though I would have expected something simple as this ...

function* numbers(max) {
  let n = 0;
  while (counter < max) {
    yield n++;
  }
}

for (let n in numbers(10)) {
  console.log(n);
}

... which is much more readable and concise, but apparently it's not as easy as that yet? I've tried node 0.12.7 with --harmony flag and also node 4.0.0 rc1. Is there something else I have to do to enable this feature (including the usage of let while I am at it) if this is even available yet?

Answer 1

You need to use the for..of syntax for generators. This creates a loop for iterable objects.

function* numbers(max) {
  let n = 0;
  while (n < max) {
    yield n++;
  }
}

Using it:

for (let n of numbers(10)) {
  console.log(n); //0123456789
}

Documentation