# This code is part of a Qiskit project.
#
# (C) Copyright IBM 2022, 2023.
#
# This code is licensed under the Apache License, Version 2.0. You may
# obtain a copy of this license in the LICENSE.txt file in the root directory
# of this source tree or at http://www.apache.org/licenses/LICENSE-2.0.
#
# Any modifications or derivative works of this code must retain this
# copyright notice, and modified files need to carry a notice indicating
# that they have been altered from the originals.
"""Property containment utilities."""
from __future__ import annotations
from collections.abc import MutableSet
from collections import OrderedDict
from typing import Generator
from qiskit_nature.second_q.properties import SparseLabelOpsFactory
[documentos]class PropertiesContainer(MutableSet):
"""The properties container class.
This class manages storage of :class:`~qiskit_nature.second_q.properties.Property` objects.
These objects are operator factories, generating the `aux_operators` that will be passed down to
quantum algorithms which support their evaluation.
This container class can only contain **a single instance** of any
:class:`~qiskit_nature.second_q.properties.Property` kind. It enforces this via a `MutableSet`
implementation.
"""
def __init__(self) -> None:
self._properties: OrderedDict[str, SparseLabelOpsFactory] = OrderedDict()
[documentos] def add(self, value: SparseLabelOpsFactory) -> None:
key = value.__class__.__name__
if key in self._properties.keys():
raise ValueError(
f"An object of type '{key}' already exists in this Container. Please remove that "
"first, if you want to replace it with this new instance."
)
self._properties[key] = value
[documentos] def discard(self, value: str | type | SparseLabelOpsFactory) -> None:
key: str
if isinstance(value, str):
key = value
elif isinstance(value, type):
key = value.__name__
elif isinstance(value, SparseLabelOpsFactory):
key = value.__class__.__name__
else:
raise TypeError(
"Only inputs of type 'str', 'type', or 'SparseLabelOpsFactory' are supported, not "
f"{type(value)}."
)
self._properties.pop(key, None)
def __contains__(self, key: object) -> bool:
actual_key: str
if isinstance(key, str):
actual_key = key
elif isinstance(key, type):
actual_key = key.__name__
elif isinstance(key, SparseLabelOpsFactory):
actual_key = key.__class__.__name__
else:
raise TypeError(
"Only inputs of type 'str', 'type', or 'SparseLabelOpsFactory' are supported, not "
f"{type(key)}."
)
return actual_key in self._properties.keys()
def __len__(self) -> int:
return len(self._properties)
def __iter__(self) -> Generator[SparseLabelOpsFactory, None, None]:
for prop in self._properties.values():
yield prop
def _getter(self, _type: type) -> SparseLabelOpsFactory | None:
"""An internal utility method to handle the attribute getter implementation.
Args:
_type: the target SparseLabelOpsFactory type of this getter.
Returns:
The property of the corresponding type or `None` if it is not available.
"""
return self._properties.get(_type.__name__, None)
def _setter(self, _property: SparseLabelOpsFactory | None, _type: type) -> None:
"""An internal utility method to handle the attribute setter implementation.
Args:
_property: the SparseLabelOpsFactory to set. If `None`, the internally stored property of the
indicated type (see next argument) will be discarded instead of set.
_type: the target SparseLabelOpsFactory type of this setter.
Raises:
TypeError: if the provided SparseLabelOpsFactory does not match the indicate type.
"""
if _property is None:
self.discard(_type)
return
if not isinstance(_property, _type):
raise TypeError(
f"Only objects of type '{_type.__name__}' are supported, not {type(_property)}."
)
self.add(_property)