Is it possible to define/constrain the JSON response more specifically

[jazelly]

The support of GGML BNF is awesome. Is there any chance to specify the grammer even at more specific level, e.g.

interface Field {
  name: string;
  type: 'single-choice' | 'multiple-choice' | 'input';
}
// instead of 
interface Field {
  name: string;
  type: string;
}

If not at the GGML level, had anyone tried the similar thing at application level, perhaps with prompting to limit the answer to a few options?

[giladgd]

This is possible by using a JSON schema grammar