# This code is part of Qiskit.
#
# (C) Copyright IBM 2017, 2019.
#
# 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.
"""Parameter Vector Class to simplify management of parameter lists."""
from uuid import uuid4, UUID
from .parameter import Parameter
class ParameterVectorElement(Parameter):
"""An element of a ParameterVector."""
___slots__ = ("_vector", "_index")
def __new__(cls, vector, index, uuid=None): # pylint:disable=unused-argument
obj = object.__new__(cls)
if uuid is None:
obj._uuid = uuid4()
else:
obj._uuid = uuid
obj._hash = hash(obj._uuid)
return obj
def __getnewargs__(self):
return (self.vector, self.index, self._uuid)
def __init__(self, vector, index, uuid=None): # pylint: disable=unused-argument
name = f"{vector.name}[{index}]"
super().__init__(name)
self._vector = vector
self._index = index
@property
def index(self):
"""Get the index of this element in the parent vector."""
return self._index
@property
def vector(self):
"""Get the parent vector instance."""
return self._vector
def __getstate__(self):
return {
"name": self._name,
"uuid": self._uuid,
"vector": self._vector,
"index": self._index,
}
def __setstate__(self, state):
self._name = state["name"]
self._uuid = state["uuid"]
self._vector = state["vector"]
self._index = state["index"]
super().__init__(self._name)
[ドキュメント]class ParameterVector:
"""ParameterVector class to quickly generate lists of parameters."""
__slots__ = ("_name", "_params", "_size", "_root_uuid")
def __init__(self, name, length=0):
self._name = name
self._size = length
self._root_uuid = uuid4()
root_uuid_int = self._root_uuid.int
self._params = [
ParameterVectorElement(self, i, UUID(int=root_uuid_int + i)) for i in range(length)
]
@property
def name(self):
"""Returns the name of the ParameterVector."""
return self._name
@property
def params(self):
"""Returns the list of parameters in the ParameterVector."""
return self._params
[ドキュメント] def index(self, value):
"""Returns first index of value."""
return self._params.index(value)
def __getitem__(self, key):
if isinstance(key, slice):
start, stop, step = key.indices(self._size)
return self.params[start:stop:step]
if key > self._size:
raise IndexError(f"Index out of range: {key} > {self._size}")
return self.params[key]
def __iter__(self):
return iter(self.params[: self._size])
def __len__(self):
return self._size
def __str__(self):
return f"{self.name}, {[str(item) for item in self.params[: self._size]]}"
def __repr__(self):
return f"{self.__class__.__name__}(name={self.name}, length={len(self)})"
[ドキュメント] def resize(self, length):
"""Resize the parameter vector.
If necessary, new elements are generated. If length is smaller than before, the
previous elements are cached and not re-generated if the vector is enlarged again.
This is to ensure that the parameter instances do not change.
"""
if length > len(self._params):
root_uuid_int = self._root_uuid.int
self._params.extend(
[
ParameterVectorElement(self, i, UUID(int=root_uuid_int + i))
for i in range(len(self._params), length)
]
)
self._size = length