Class DataclassTransformSpec

mypy/nodes.py:5129–5197

Specifies how a dataclass-like transform should be applied. The fields here are based on the parameters accepted by `typing.dataclass_transform`.

class DataclassTransformSpec:
    """Specifies how a dataclass-like transform should be applied. The fields here are based on the
    parameters accepted by `typing.dataclass_transform`."""

    __slots__ = (
        "eq_default",
        "order_default",
        "kw_only_default",
        "frozen_default",
        "field_specifiers",
    )

    def __init__(
        self,
        *,
        eq_default: bool | None = None,
        order_default: bool | None = None,
        kw_only_default: bool | None = None,
        field_specifiers: tuple[str, ...] | None = None,
        # Specified outside of PEP 681:
        # frozen_default was added to CPythonin https://github.com/python/cpython/pull/99958 citing
        # positive discussion in typing-sig
        frozen_default: bool | None = None,
    ) -> None:
        self.eq_default = eq_default if eq_default is not None else True
        self.order_default = order_default if order_default is not None else False
        self.kw_only_default = kw_only_default if kw_only_default is not None else False
        self.frozen_default = frozen_default if frozen_default is not None else False
        self.field_specifiers = field_specifiers if field_specifiers is not None else ()

    def serialize(self) -> JsonDict:
        return {
            "eq_default": self.eq_default,
            "order_default": self.order_default,
            "kw_only_default": self.kw_only_default,
            "frozen_default": self.frozen_default,
            "field_specifiers": list(self.field_specifiers),
        }

    @classmethod
    def deserialize(cls, data: JsonDict) -> DataclassTransformSpec:
        return DataclassTransformSpec(
            eq_default=data.get("eq_default"),
            order_default=data.get("order_default"),
            kw_only_default=data.get("kw_only_default"),
            frozen_default=data.get("frozen_default"),
            field_specifiers=tuple(data.get("field_specifiers", [])),
        )

    def write(self, data: WriteBuffer) -> None:
        write_tag(data, DT_SPEC)
        write_bool(data, self.eq_default)
        write_bool(data, self.order_default)
        write_bool(data, self.kw_only_default)
        write_bool(data, self.frozen_default)
        write_str_list(data, self.field_specifiers)
        write_tag(data, END_TAG)