I’ve noticed that TOON still seems to use a few extra tokens in some cases - specifically when handling smaller nested structures that include nested arrays with single keys.

Example

Input

{
  "data": {
    "metadata": {
      "items": ["a", "b"]
    }
  }
}

Current Output

data:
  metadata:
    items[2]: a,b

Proposed Output

data.metadata.items[2]: a,b

The idea here is to squeeze out a few more token savings in some edge cases, following how OmegaConf handles dotted keys. Any time a dictionary has more than one keys, we can fall back to the current implementation.

TOON is definitely an exceptional work, just giving my two cents.