Example 6-15. Computing a series of values using a generator

function* fib() {
	var a = 0;
	var b = 1;
	while (true) {
		yield a + b;
		b = a + b;
		a = b - a;
	}
}

var i;
var result;
var iterator = fib();

for (i = 0; i < 5; i++) {
	result = iterator.next();
	console.log(result.value);
}

// Console output is identical to the previous example
// 1
// 2
// 3
// 5
// 8