iterateOverCombinedItems.js

export function* iterateOverCombinedItems(items) {
  if (items.length === 0) {
    return
  }

  const [h, ...tail] = items

  const heads = Array.isArray(h) ? h : [h]

  for (const head of heads) {
    if (tail.length > 0) {
      for (const subResult of iterateOverCombinedItems(tail)) {
        yield [head, ...subResult]
      }
    } else {
      yield [head]
    }
  }
}