Source code for symforce.ops.impl.nonetype_lie_group_ops

# ----------------------------------------------------------------------------
# SymForce - Copyright 2022, Skydio, Inc.
# This source code is under the Apache 2.0 license found in the LICENSE file.
# ----------------------------------------------------------------------------
from symforce import typing as T
from symforce.ops.impl.abstract_vector_lie_group_ops import AbstractVectorLieGroupOps

NoneElementOrType = T.Union[None, T.Type[None]]


class NoneTypeLieGroupOps(AbstractVectorLieGroupOps[None]):
    """
    Class for implementing ops on ``None`` object. This is primarily used when performing ops
    on dataclasses with optional fields which could be ``None``.

    :mod:`.abstract_vector_lie_group_ops` lets us only implement the StorageOps functions, and use
    those functions to perform Group and LieGroup ops.
    """

    @staticmethod
    def storage_dim(a: NoneElementOrType) -> int:
        return 0

    @staticmethod
    def to_storage(a: None) -> T.List[T.Scalar]:
        return []

    @staticmethod
    def from_storage(a: NoneElementOrType, elements: T.Sequence[T.Scalar]) -> None:
        assert len(elements) == 0
        return None

    @staticmethod
    def symbolic(a: NoneElementOrType, name: str, **kwargs: T.Dict) -> None:
        return None