code: function elementAtOrDefault(index, or) {
      return function (it) {
          let i = 0;
          for (const item of it) {
              if (i === index) {
                  return item;
              }
              i = i + 1;
          }
          return or;
      };
  }
docs: Enumerate until index and return the element at index, or consumes and return undefined