View source on GitHub
|
A modifier that adds a group parity control to other cells in the column.
Inherits From: Cell
cirq.interop.quirk.cells.control_cells.ParityControlCell(
qubits: Iterable['cirq.Qid'], basis_change: Iterable['cirq.Operation']
)
The parity controls in a column are satisfied as a group if an odd number of them are individually satisfied.
Methods
basis_change
basis_change() -> 'cirq.OP_TREE'
Operations to conjugate a column with.
The main distinctions between operations performed during the body of a column and operations performed during the basis change are:
- Basis change operations are not affected by operation modifiers in the column. For example, adding a control into the same column will not affect the basis change.
- Basis change operations happen twice, once when starting a column and a second time (but inverted) when ending a column.
| Returns | |
|---|---|
A cirq.OP_TREE of basis change operations.
|
controlled_by
controlled_by(
qubit: 'cirq.Qid'
) -> 'Cell'
The same cell, but with an explicit control on its main operations.
Cells with effects that do not need to be controlled are permitted to return themselves unmodified.
| Args | |
|---|---|
qubit
|
The control qubit. |
| Returns | |
|---|---|
| A modified cell with an additional control. |
gate_count
gate_count() -> int
Cheaply determines an upper bound on the resulting circuit size.
The upper bound may be larger than the actual count. For example, a
small circuit may nevertheless have involved a huge amount of rewriting
work to create. In such cases the gate_count is permitted to be large
to indicate the danger, despite the output being small.
This method exists in order to defend against billion laugh type attacks. It is important that counting is fast and efficient even in extremely adversarial conditions.
modify_column
modify_column(
column: List[Optional['Cell']]
)
Applies this cell's modification to its column.
For example, a control cell will add a control qubit to other operations in the column.
| Args | |
|---|---|
column
|
A mutable list of cells in the column, including empty
cells (with value None). This method is permitted to change
the items in the list, but must not change the length of the
list.
|
| Returns | |
|---|---|
Nothing. The column argument is mutated in place.
|
operations
operations() -> 'cirq.OP_TREE'
Returns operations that implement the cell's main action.
| Returns | |
|---|---|
A cirq.OP_TREE of operations implementing the cell.
|
| Raises | |
|---|---|
ValueError
|
The cell is not ready for conversion into operations, e.g. it may still have unspecified inputs. |
persistent_modifiers
persistent_modifiers() -> Dict[str, Callable[['Cell'], 'Cell']]
Overridable modifications to apply to the rest of the circuit.
Persistent modifiers apply to all cells in the same column and also to all cells in future columns (until a column overrides the modifier with another one using the same key).
| Returns | |
|---|---|
| A dictionary of keyed modifications. Each modifier lasts until a later cell specifies a new modifier with the same key. |
with_input
with_input(
letter: str, register: Union[Sequence['cirq.Qid'], int]
) -> 'Cell'
The same cell, but linked to an explicit input register or constant.
If the cell doesn't need the input, it is returned unchanged.
| Args | |
|---|---|
letter
|
The input variable name ('a', 'b', or 'r'). |
register
|
The list of qubits to use as the input, or else a classical constant to use as the input. |
| Returns | |
|---|---|
| The same cell, but with the specified input made explicit. |
with_line_qubits_mapped_to
with_line_qubits_mapped_to(
qubits: List['cirq.Qid']
) -> 'Cell'
Returns the same cell, but targeting different qubits.
It is assumed that the cell is currently targeting LineQubit
instances, where the x coordinate indicates the qubit to take from the
list.
| Args | |
|---|---|
qubits
|
The new qubits. The qubit at offset x will replace
cirq.LineQubit(x).
|
| Returns | |
|---|---|
| The same cell, but with new qubits. |
__eq__
__eq__(
other: _SupportsValueEquality
) -> bool
__ne__
__ne__(
other: _SupportsValueEquality
) -> bool