http://swannodette.github.io/2013/08/24/es6-generators-and-csp/ ported to SpiderMonkey (at least until ES6 generators are fully supported, which should be within the next month or so)

go.js

function go_(machine, step) {
  while(!step.done) {
    try {
      var arr   = step(),
          state = arr[0],
          value = arr[1];

      switch (state) {
        case "park":
          setImmediate(function() { go_(machine, step); });
          return;
        case "continue":
          step = machine.next(value);
          break;
      }
    } catch(e) {
      // todo: only catch stop iteration
      return;
    }
  }
}

function go(machine) {
  var gen = machine();
  go_(gen, gen.next());
}

function put(chan, val) {
  return function() {
    if(chan.length == 0) {
      chan.unshift(val);
      return ["continue", null];
    } else {
      return ["park", null];
    }
  };
}

function take(chan) {
  return function() {
    if(chan.length == 0) {
      return ["park", null];
    } else {
      var val = chan.pop();
      return ["continue", val];
    }
  };
}


/////////////////////////////////////////////

var c = [];

go(function () {
  for(var i = 0; i < 10; i++) {
    yield put(c, i);
    console.log("process one put", i);
  }
  yield put(c, null);
});

go(function () {
  while(true) {
    var val = yield take(c);
    if(val == null) {
      break;
    } else {
      console.log("process two took", val);
    }
  }
});

// todo: use postMessage
window.setImmediate = cb => setTimeout(cb, 0);