Generators execution flow example

gen.js

"use strict";

const vo = require("vo");

function wait(fn, time) {
    time = time || 0;

    if (typeof fn === "function") {
        fn = fn();
    }

    return new Promise(resolve => setTimeout(() => {
        resolve(fn);
    }, time));
}

// A and B are executed in series
function* A() {
    console.log("A");
    return yield ["A"];
}

function* B() {
    console.log("B");
    return yield ["B"];
}

// C and D are executed in parallel
function* C() {
    const randTime = ~~(Math.random() * 3000);

    return yield wait(() => {

        console.log("C");
        return ["C", "F"]
    }, randTime);
    // return yield ["C"];
}

function* D() {
    console.log("D");
    return yield ["D"];
}

vo(A, B, [C, D])(function (err) {
    if (err) throw err;

    console.log("Result", err, arguments);
});