Source code for qiskit.converters.circuit_to_dagdependency

# This code is part of Qiskit.
#
# (C) Copyright IBM 2020.
#
# 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
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'''Helper function for converting a circuit to a dag dependency'''

from qiskit.dagcircuit.dagdependency import DAGDependency


[docs]def circuit_to_dagdependency(circuit):
    """Build a ``DAGDependency`` object from a ``QuantumCircuit``.

    Args:
        circuit (QuantumCircuit): the input circuits.

    Return:
        DAGDependency: the DAG representing the input circuit as a dag dependency.
    """
    dagdependency = DAGDependency()
    dagdependency.name = circuit.name

    for register in circuit.qregs:
        dagdependency.add_qreg(register)

    for register in circuit.cregs:
        dagdependency.add_creg(register)

    for operation, qargs, cargs in circuit.data:
        dagdependency.add_op_node(operation, qargs, cargs)

    dagdependency._add_successors()

    return dagdependency