message: Add comments to helper structure for IndexArray::index_string_all_ins.
diff: @@ -321,7 +321,7 @@ void IndexArray::from_list_all(StringData value, IntegerColumn& result, const In
  namespace {
  -// Helper functions for index_string_all_ins for generating permutations of index keys
  +// Helper functions for SearchList (index_string_all_ins) for generating permutations of index keys
  // replicates the 4 least significant bits each times 8
  // eg: abcd -> aaaaaaaabbbbbbbbccccccccdddddddd
  @@ -349,6 +349,8 @@ key_type generate_key(key_type upper, key_type lower, int permutation) {
  }
  +// Helper structure for IndexArray::index_string_all_ins to generate and keep track of search key permutations,
  +// when traversing the trees.
  struct SearchList {
  struct Item {
  const char* header;
  @@ -363,6 +365,7 @@ struct SearchList {
  m_keys_seen.reserve(num_permutations);
  }
  + // Add all unique keys for this level to the internal work stack
  void add_all_for_level(const char* header, size_t string_offset)
  {
  m_keys_seen.clear();
  @@ -392,6 +395,7 @@ struct SearchList {
  return item;
  }
  + // Add a single entry to the internal work stack. Used to traverse the inner trees (same key)
  void add_next(const char* header, size_t string_offset, key_type key)
  {
  m_items.push_back({header, string_offset, key});
  