Function _default_field_meta

python/pyfory/struct.py:159–184

Returns default field metadata for fields without pyfory.field(). A field is considered nullable if: 1. It's Optional[T], OR 2. Global field_nullable is True, OR 3. In Python-native mode, it is a dynamic field such as Any or a bare collection alias. Xlang fields are non-nullabl

(type_hint: type, field_nullable: bool = False, xlang: bool = False)

def _default_field_meta(type_hint: type, field_nullable: bool = False, xlang: bool = False) -> ForyFieldMeta:
    """Returns default field metadata for fields without pyfory.field().

    A field is considered nullable if:
    1. It's Optional[T], OR
    2. Global field_nullable is True, OR
    3. In Python-native mode, it is a dynamic field such as Any or a bare collection alias.

    Xlang fields are non-nullable by default so schema fingerprints and payload flags stay aligned
    with other runtimes unless users opt into nullability explicitly.

    For ref, defaults to False to preserve original serialization behavior.
    Non-nullable complex fields use write_no_ref (no ref header in buffer).
    Users can explicitly set ref=True in pyfory.field() to enable ref tracking.

    For dynamic, defaults to None (auto-detect):
    - Abstract classes: always True (type info must be written)
    - Concrete types use type-id based dynamic detection
    """
    unwrapped_type, is_optional = unwrap_optional(type_hint)
    nullable = is_optional or field_nullable or (not xlang and _is_dynamic_nullable_default(unwrapped_type))
    # Default ref=False to preserve original serialization behavior where non-nullable
    # fields use write_no_ref. Users can explicitly set ref=True in pyfory.field()
    # to enable per-field ref tracking when fory.track_ref is enabled.
    # Default dynamic=None for auto-detection based on type and mode
    return ForyFieldMeta(id=-1, nullable=nullable, ref=False, ignore=False, dynamic=None)


def _extract_field_infos(