cons.js

const cons = (x, y) => (m) => m(x, y);
const car = (z) => z((p, q) => p);
const cdr = (z) => z((p, q) => q);

const pair = cons(1, 2);
console.log(car(pair), cdr(pair));//1 2

const list = cons(1, cons(2, cons(3, cons(4, null))));
const each = (l, fn) => cdr(l) ? (() => {fn(car(l)); each(cdr(l), fn)})() : fn(car(l));
each(list, console.log);//1 2 3 4