How about add groupToArray or chunk?

[yuhj86]

const array = [1, 2, 3, 4, 5];

array.groupToArray((num, index, array) => {
  return Math.floor(index / 2)
});

// or array.chunk(2);
// =>  Array [[1, 2], [3, 4], [5]]

[jridgewell]

How would this handle non-adjacent runs? Eg:

const array = [1, 2, 3, 1, 2];

array.groupToArray((num, index, array) => {
  return Math.floor(index / 2)
});

// [[1, 2], [3], [1, 2]]
// OR
// =>  Array [[1, 2, 1, 2], [3]]

The first is similar to python's itertools.groupby, and we've discussed exposing a similar API with iterators in committee. But the second effectively the same as Object.values(array.groupBy(…)), and so would be unlikely to be added.

[ljharb]

#44 (comment)

The proposal has been demoted to stage 2, with the expectation that I will be requesting stage 3 for it in July with static methods (#47).

[michaelficarra]

@yuhj86 I plan to propose a chunk helper as a follow-up to the iterator helpers MVP.