Documentation

baml.json.from

Converts any BAML value to a `json` value.

Reference version

Signature

function baml.json.from(
value: unknown,
naming: baml.json.Naming = …,
omit_nulls: bool = …
) -> baml.json.json throws baml.json.SerializationError

Converts any BAML value to a json value.

The conversion follows the value's runtime type. Primitives, lists, and maps take their natural JSON shape. A class instance becomes an object of its fields, an enum value its variant's name, and media the tagged object { kind, source, value, mime, name? }. A bigint becomes an arbitrary-precision JSON number. A float that is NaN or infinite stays as it is: a json value holds it, but stringify refuses to write it.

A value whose runtime class implements baml.ToJson with its own to_json is converted by that method instead, at any depth, and the method owns its whole subtree: naming and omit_nulls do not reach inside it. The method is found from the value's runtime class, so one declared in any package is honored.

naming picks the names fields and variants go by. The default, Naming.Declared, writes every field under its declared name. Naming.Aliased writes a field or variant under its @alias, and leaves out a @skip field.

omit_nulls leaves out a class field that holds null, so an unset optional field writes {"name": "Ada"} rather than {"name": "Ada", "nickname": null}. Nothing else is left out: a null map value, a null list element, and a null nested in a json value stay, because there null is data.

Throws

  • baml.json.SerializationError if any value in the graph has no JSON form: a uint8array (encode it explicitly with to_base64() or to_hex()), a function, a future, a map whose keys are not strings, a value that contains itself, or any other opaque runtime object. reason names which.
  • baml.json.SerializationError if naming is Naming.Aliased and the value holds a @skip enum variant, which then has no name.

Source:<builtin>/baml/ns_json/json.bamlbytes 9869–10058