Sor

class ML {
    push( k ) {
        this.e ? this.e.n = this.e = { k } : this.b = this.e = { k }
    }
    shift() {
        if ( this.pv = this.b) {
            this.b = this.b.n
            return this.pv.k
        }
    }
    forEach( f ) {
        let e = this.b, i = 0
        while (e) f( e.k, i++, e ), e = e.n
    }
}

//const ml = new ML()
const ml = []

var t1 = Date.now()

for (var i=0;i<1000000;i++) {
    ml.push(1000)
}
for (var i=0;i<1000000;i++) {
    ml.shift()
}

var t2 = Date.now()

console.log(t2-t1);