Fibonacci Generator

fibonacci.js

require('fibers');

// Generator function. Returns a function which returns incrementing
// Fibonacci numbers with each call.
function Fibonacci() {
  // Create a new fiber which yields sequential Fibonacci numbers
  var fiber = Fiber(function() {
    Fiber.yield(0); // F(0) -> 0
    var prev = 0, curr = 1;
    while (true) {
      Fiber.yield(curr);
      var tmp = prev + curr;
      prev = curr;
      curr = tmp;
    }
  });
  // Return a bound handle to `run` on this fiber
  return fiber.run.bind(fiber);
}

// Initialize a new Fibonacci sequence and iterate up to 1597
var seq = Fibonacci();
for (var ii = seq(); ii <= 1597; ii = seq()) {
  console.log(ii);
}

output

0
1
1
2
3
5
8
13
21
34
55
89
144
233
377
610
987
1597