# Copyright (C) 2024 qBraid
#
# This file is part of the qBraid-SDK
#
# The qBraid-SDK is free software released under the GNU General Public License v3
# or later. You can redistribute and/or modify it under the terms of the GPL v3.
# See the LICENSE file in the project root or <https://www.gnu.org/licenses/gpl-3.0.html>.
#
# THERE IS NO WARRANTY for the qBraid-SDK, as per Section 15 of the GPL v3.
"""
Module for conversions from QASM 2 to Cirq Circuits
"""
from __future__ import annotations
from typing import TYPE_CHECKING
import pyqasm
from qbraid_core._import import LazyLoader
from qbraid._logging import logger
from qbraid.programs.exceptions import QasmError
from qbraid.transpiler.annotations import weight
cirq_qasm_import = LazyLoader("cirq_contrib", globals(), "cirq.contrib.qasm_import")
cirq_qasm_parser = LazyLoader(
"cirq_qasm_parser", globals(), "qbraid.transpiler.conversions.qasm2.cirq_qasm_parser"
)
if TYPE_CHECKING:
import cirq
from qbraid.programs.typer import Qasm2StringType
from qbraid.transpiler.conversions.qasm2.cirq_qasm_parser import QasmParser
[docs]
@weight(1)
def qasm2_to_cirq(qasm: Qasm2StringType) -> cirq.Circuit:
"""Returns a Cirq circuit equivalent to the input QASM string.
Args:
qasm: QASM string to convert to a Cirq circuit.
Returns:
Cirq circuit representation equivalent to the input QASM string.
"""
try:
qasm_module = pyqasm.loads(qasm)
qasm_module.unroll(external_gates=["rzz"])
if qasm_module.has_barriers():
logger.warning(
"Barriers are not supported in Cirq, "
"and will be removed during program conversion."
)
qasm_module.remove_barriers()
parser: QasmParser = cirq_qasm_parser.QasmParser()
qasm_compat = pyqasm.dumps(qasm_module)
qasm_parsed = parser.parse(qasm_compat)
return qasm_parsed.circuit
except cirq_qasm_import.QasmException as err:
raise QasmError(err) from err