from david nolan's 24 aug 2013 post - http://swannodette.github.io/2013/08/24/es6-generators-and-csp

generator-channel-example.js

// 17 Sept 2019
// from david nolan's 24 aug 2013 post - http://swannodette.github.io/2013/08/24/es6-generators-and-csp

function go_(it, step) {
  console.log({ it, step });
  
  while(!step.done) {
    var arr   = step.value(),
        state = arr[0],
        value = arr[1];

    switch (state) {
      case "park":
        // setImmediate(function() { go_(machine, step); });
        setTimeout(function() { go_(it, step); }, 1);
        return;
      case "continue":
        step = it.next(value);
        break;
    }
  }
}

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

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

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

/* test it out */

var c = ['a'];

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


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