InstructionSet
class InstructionSet(circuit_cregs=None, *, resource_requester=None)
Bases: object
Instruction collection, and their contexts.
New collection of instructions.
The context (qargs and cargs that each instruction is attached to) is also stored separately for each instruction.
Parameters
-
circuit_cregs (list[ClassicalRegister]) –
Optional. List of cregs of the circuit to which the instruction is added. Default: None.
Deprecated since version qiskit-terra0.19 The classical registers are insufficient to access all classical resources in a circuit, as there may be loose classical bits as well. It can also cause integer indices to be resolved incorrectly if any registers overlap. Instead, pass a complete requester to the
resource_requesterargument. -
resource_requester (
Optional[Callable]) –A callable that takes in the classical resource used in the condition, verifies that it is present in the attached circuit, resolves any indices into concrete
Clbitinstances, and returns the concrete resource. If this is not given, specifying a condition with an index is forbidden, and all concreteClbitandClassicalRegisterresources will be assumed to be valid.NoteThe callback
resource_requesteris called once for each call toc_if(), and assumes that a call implies that the resource will now be used. It may throw an error if the resource is not valid for usage.
Raises
CircuitError – if both resource_requester and circuit_cregs are passed. Only one of these may be passed, and it should be resource_requester.
Methods
add
InstructionSet.add(instruction, qargs=None, cargs=None)
Add an instruction and its context (where it is attached).
c_if
InstructionSet.c_if(classical, val)
Set a classical equality condition on all the instructions in this set between the ClassicalRegister or Clbit classical and value val.
This is a setter method, not an additive one. Calling this multiple times will silently override any previously set condition on any of the contained instructions; it does not stack.
Parameters
- classical (
Union[Clbit,ClassicalRegister,int]) – the classical resource the equality condition should be on. If this is given as an integer, it will be resolved into aClbitusing the same conventions as the circuit these instructions are attached to. - val (
int) – the value the classical resource should be equal to.
Return type
Returns
This same instance of InstructionSet, but now mutated to have the given equality condition.
Raises
CircuitError – if the passed classical resource is invalid, or otherwise not resolvable to a concrete resource that these instructions are permitted to access.
Example
from qiskit import ClassicalRegister, QuantumRegister, QuantumCircuit
qr = QuantumRegister(2)
cr = ClassicalRegister(2)
qc = QuantumCircuit(qr, cr)
qc.h(range(2))
qc.measure(range(2), range(2))
# apply x gate if the classical register has the value 2 (10 in binary)
qc.x(0).c_if(cr, 2)
# apply y gate if bit 0 is set to 1
qc.y(1).c_if(0, 1)
qc.draw() ┌───┐┌─┐ ┌───┐
q0_0: ┤ H ├┤M├────┤ X ├─────────────
├───┤└╥┘┌─┐ └─╥─┘ ┌───┐
q0_1: ┤ H ├─╫─┤M├───╫──────┤ Y ├────
└───┘ ║ └╥┘ ║ └─╥─┘
║ ║ ┌──╨──┐┌────╨─────┐
c0: 2/══════╩══╩═╡ 0x2 ╞╡ c0_0=0x1 ╞
0 1 └─────┘└──────────┘inverse
InstructionSet.inverse()
Invert all instructions.
Attributes
cargs
Legacy getter for the cargs components of an instruction set. This does not support mutation.
instructions
Legacy getter for the instruction components of an instruction set. This does not support mutation.
qargs
Legacy getter for the qargs components of an instruction set. This does not support mutation.