Paramorphism, extended catamorphism, fold, iteration

paralk.js

const paralk = f => acc => xs => {
  const next = (acc, [head, ...tail]) => head === undefined
   ? acc
   : f(acc) (head, tail, acc => next(acc, tail));

  return next(acc, xs);
};

const drop = n => paralk(acc => (x, tail, k) => acc.length + 1 === n ? tail : (acc.push(x), k(acc))) ([]);

drop(3) ([1,2,3,4,5]); // yields [4,5]