def dagger(self, inv_dict=None, suffix="-INV"):
"""
Creates the conjugate transpose of the Quil program. The program must not
contain any irreversible actions (measurement, control flow, qubit allocation).
:return: The Quil program's inverse
:rtype: Program
"""
if not self.is_protoquil():
raise ValueError("Program must be valid Protoquil")
daggered = Program()
for gate in self._defined_gates:
if inv_dict is None or gate.name not in inv_dict:
if gate.parameters:
raise TypeError(
"Cannot auto define daggered version of parameterized gates"
)
daggered.defgate(gate.name + suffix, gate.matrix.T.conj())
for gate in reversed(self._instructions):
reversed_gate = None
qubits = [unpack_qubit(q) for q in gate.qubits]
if gate.name in QUANTUM_GATES:
if gate.name == "S":
reversed_gate = Gate("PHASE", [-pi / 2], qubits)
elif gate.name == "T":
reversed_gate = Gate("RZ", [pi / 4], qubits)
elif gate.name == "ISWAP":
reversed_gate = Gate("PSWAP", [pi / 2], qubits)
else:
negated_params = list(map(lambda x: -1 * x, gate.params))
reversed_gate = Gate(gate.name, negated_params, qubits)
reversed_gate.modifiers = gate.modifiers
daggered.inst(reversed_gate)
else:
if inv_dict is None or gate.name not in inv_dict:
gate_inv_name = gate.name + suffix
else:
gate_inv_name = inv_dict[gate.name]
reversed_gate = Gate(gate_inv_name, gate.params, qubits)
reversed_gate.modifiers = gate.modifiers
daggered.inst(reversed_gate)
return daggered
def address_qubits(program, qubit_mapping=None):
"""
Takes a program which contains placeholders and assigns them all defined values.
Either all qubits must be defined or all undefined. If qubits are
undefined, you may provide a qubit mapping to specify how placeholders get mapped
to actual qubits. If a mapping is not provided, integers 0 through N are used.
This function will also instantiate any label placeholders.
:param program: The program.
:param qubit_mapping: A dictionary-like object that maps from :py:class:`QubitPlaceholder`
to :py:class:`Qubit` or ``int`` (but not both).
:return: A new Program with all qubit and label placeholders assigned to real qubits and labels.
"""
fake_qubits, real_qubits, qubits = _what_type_of_qubit_does_it_use(program)
if real_qubits:
if qubit_mapping is not None:
warnings.warn(
"A qubit mapping was provided but the program does not "
"contain any placeholders to map!")
return program
if qubit_mapping is None:
qubit_mapping = {qp: Qubit(i) for i, qp in enumerate(qubits)}
else:
if all(isinstance(v, Qubit) for v in qubit_mapping.values()):
pass # we good
elif all(isinstance(v, int) for v in qubit_mapping.values()):
qubit_mapping = {k: Qubit(v) for k, v in qubit_mapping.items()}
else:
raise ValueError(
"Qubit mapping must map to type Qubit or int (but not both)")
result = []
for instr in program:
# Remap qubits on Gate, Measurement, and ResetQubit instructions
if isinstance(instr, Gate):
remapped_qubits = [qubit_mapping[q] for q in instr.qubits]
gate = Gate(instr.name, instr.params, remapped_qubits)
gate.modifiers = instr.modifiers
result.append(gate)
elif isinstance(instr, Measurement):
result.append(
Measurement(qubit_mapping[instr.qubit], instr.classical_reg))
elif isinstance(instr, ResetQubit):
result.append(ResetQubit(qubit_mapping[instr.qubit]))
elif isinstance(instr, Pragma):
new_args = []
for arg in instr.args:
# Pragmas can have arguments that represent things besides qubits, so here we
# make sure to just look up the QubitPlaceholders.
if isinstance(arg, QubitPlaceholder):
new_args.append(qubit_mapping[arg])
else:
new_args.append(arg)
result.append(
Pragma(instr.command, new_args, instr.freeform_string))
# Otherwise simply add it to the result
else:
result.append(instr)
new_program = program.copy()
new_program._instructions = result
return new_program
