Does node.js support yield?

Question

Is there any way to get generators into node.js?

I\'m currently faking them with callbacks, but I have to remember to check the response of the callback inside of my gen

Answer 1

Update 2014: Node does support callbacks now. The following is a post from 2010.

---

You should use callbacks. If the function does something asynchronously, you may also want a continuation callback (continuation is a bad word, since it also means something else, but you get my point.)

primes(function(p) {
  if (p > 100) return false // i assume this stops the yielding
  do_something(p)
  return true // it's also better to be consistent
}, function(err) { // fire when the yield callback returns false
  if (err) throw err // error from whatever asynch thing you did
  // continue...
})

Updated with example code

I flipped it, so that it returns true on complete (since null, false and undefined all evaluate to false anyways).

function primes(callback) {
  var n = 1, a = true;
  search: while (a)  {
    n += 1;
    for (var i = 2; i <= Math.sqrt(n); i += 1)
      if (n % i == 0)
        continue search;
    if (callback(n)) return
  }
}

primes(function(p) {
  console.log(p)
  if (p > 100) return true
})