Inconsistent `tags` argument in `Taggable.{__init__, _with_new_tags, tagged}`

[matthiasdiener]

I wonder whether they should all accept tags: ToTagSetConvertible instead of the current mix of tags: ToTagSetConvertible and tags: FrozenSet[Tag].

pytools/pytools/tag.py

Lines 253 to 284 in ea121e1

	def __init__(self, tags: FrozenSet[Tag] = frozenset()):
	"""
	Constructor for all objects that possess a `tags` attribute.
	:arg tags: a :class:`frozenset` of :class:`~pytools.tag.Tag` objects.
	Tags can be modified via the :meth:`~pytools.tag.Taggable.tagged` and
	:meth:`~pytools.tag.Taggable.without_tags` routines. Input checking
	of *tags* should be performed before creating a
	:class:`~pytools.tag.Taggable` instance, using
	:func:`~pytools.tag.check_tag_uniqueness`.
	"""
	self.tags = tags
	def _with_new_tags(self, tags: FrozenSet[Tag]) -> Self:
	"""
	Returns a copy of *self* with the specified tags. This method
	should be overridden by subclasses.
	"""
	from warnings import warn
	warn(f"_with_new_tags() for {self.__class__} fell back "
	"to using copy(). This is deprecated and will stop working in "
	"July of 2022. Instead, override _with_new_tags to specify "
	"how tags should be applied to an instance.",
	DeprecationWarning, stacklevel=2)
	# mypy is right: we're not promising this attribute is defined.
	# Once this deprecation expires, this will go back to being an
	# abstract method.
	return self.copy(tags=tags) # type: ignore[attr-defined] # pylint: disable=no-member # noqa: E501
	def tagged(self, tags: ToTagSetConvertible) -> Self:
	"""

[inducer]

That's on purpose. Constructors are supposed to be cheap. ToTagSetConvertible is subject to normalization, after which it becomes FrozenSet[Tag]. Normalization is kept out of the constructor code path specifically to avoid paying the normalization cost repeatedly.