function referenceFull(code) {
    assert(code === codes.leftSquareBracket, 'expected left bracket')
    return factoryLabel.call(
      self,
      effects,
      referenceFullAfter,
      referenceFullMissing,
      types.reference,
      types.referenceMarker,
      types.referenceString
    )(code)
  }
In a reference (full), at the `[`.

```markdown
> | [a][b] d
       ^
```

@type {State}