A simple JavaScript implementation of sleep using the yield command.

sleep.js

/* jshint esversion:6 */

function * main (){
    console.log('Every time you need a sleep, you can yield the number of seconds that you want to wait..');
    yield 5;
    console.log('..this will be executed 5 seconds later');
    yield 1.5;
    console.log('[long wait]');
    yield 10;
    console.log('..and, this after 10 seconds.\n');

    for (let i=0;i<5;i++){
        console.log('Have fun!');
        yield 1;
    }
}
execute_with_sleep(main);



/** LIBRARY CODE */
function execute_with_sleep(f){
    let gen = f();
    (function execute_rec(gen){
        let out = gen.next();
        if (!out.done &&
            !isNaN(parseFloat(out.value)) && isFinite(out.value)){
            setTimeout(() => {
                execute_rec(gen);
            }, out.value*1000);
        }
    })(gen);
}