Ctrl generalize (#400)

* Init

* Apply control through compute engine. Added Enum class

* Apply control through compute engine. Added Enum class

* Apply control through compute engine, added enum class

* Fix small bug due to wrong default value, clean up output

* abolished decomp

* Revert "abolished decomp"

This reverts commit 36743a1.

* Apply Control through decomposition. Added Test Files

* Fix a few issues with new control state

- Address inconsistency with qubit state ordering when using integers
  as input control state
- Add canonical_ctrl_state function to centralise functionality
- Fix some file encoding
- Fix tests

* Update examples/control_tester.py

* Add some missing license headers and fix some tests

* Add missing docstring

* Cleanup some code in AQT and IBM backends

* Some code cleanup in _simulator.py

* Change autoreplacer priority for control. Added Additional test for autoreplacer. Added check for canonical ctrl state func.

* Update projectq/setups/default.py

* Update projectq/setups/decompositions/cnu2toffoliandcu.py

* Update projectq/setups/decompositions/cnu2toffoliandcu.py

* Cleanup code in _replacer.py

* Tweak some of the unit tests + add comments

* Add more tests for canonical_ctrl_state and has_negative_control

* Short pass of reformatting using black

* Bug fixing for rebasing

* Reformat files. Improve control_tester examples. Update change log

* Dummy change to trigger CI with new state

* Use pytest-mock for awsbraket client testing

* Fix Linter warnings

* Use pytest-mock also for awsbraket backend tests

* Fix missing tests in backends and added support for IonQ

* Fix linter warning

* Add support for AWSBraketBackend

* Fix small typo

* Use backported mock instead of unittest.mock

* Sort requirements_tests.txt

* Fix a bunch of errors that happens at program exit

 Monkeypatching or patching of external may unload the patch before
 the MainEngine calls the last flush operations which would then call
 the original API although unwanted.

Co-authored-by: Damien Nguyen <ngn.damien@gmail.com>

.gitignore

@@ -171,6 +171,9 @@ dmypy.json
 *.out
 *.app
 
+# Others
+err.txt
+
 # ==============================================================================
 
 VERSION.txt
@@ -180,3 +183,5 @@ thumbs.db
 
 # Mac OSX artifacts
 *.DS_Store
+
+# ==============================================================================

CHANGELOG.md

@@ -19,6 +19,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Added ``pyproject.toml`` and ``setup.cfg``
 - Added CHANGELOG.md
 - Added backend for IonQ.
+- Added support for state-dependent qubit control
 
 ### Deprecated
 

examples/control_tester.py

@@ -0,0 +1,89 @@
+# -*- coding: utf-8 -*-
+#   Copyright 2021 ProjectQ-Framework (www.projectq.ch)
+#
+#   Licensed under the Apache License, Version 2.0 (the "License");
+#   you may not use this file except in compliance with the License.
+#   You may obtain a copy of the License at
+#
+#       http://www.apache.org/licenses/LICENSE-2.0
+#
+#   Unless required by applicable law or agreed to in writing, software
+#   distributed under the License is distributed on an "AS IS" BASIS,
+#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#   See the License for the specific language governing permissions and
+#   limitations under the License.
+
+from projectq.cengines import MainEngine
+from projectq.meta import Control
+from projectq.ops import All, X, Measure, CtrlAll
+
+
+def run_circuit(eng, circuit_num):
+    qubit = eng.allocate_qureg(2)
+    ctrl_fail = eng.allocate_qureg(3)
+    ctrl_success = eng.allocate_qureg(3)
+
+    if circuit_num == 1:
+        with Control(eng, ctrl_fail):
+            X | qubit[0]
+        All(X) | ctrl_success
+        with Control(eng, ctrl_success):
+            X | qubit[1]
+
+    elif circuit_num == 2:
+        All(X) | ctrl_fail
+        with Control(eng, ctrl_fail, ctrl_state=CtrlAll.Zero):
+            X | qubit[0]
+        with Control(eng, ctrl_success, ctrl_state=CtrlAll.Zero):
+            X | qubit[1]
+
+    elif circuit_num == 3:
+        All(X) | ctrl_fail
+        with Control(eng, ctrl_fail, ctrl_state='101'):
+            X | qubit[0]
+
+        X | ctrl_success[0]
+        X | ctrl_success[2]
+        with Control(eng, ctrl_success, ctrl_state='101'):
+            X | qubit[1]
+
+    elif circuit_num == 4:
+        All(X) | ctrl_fail
+        with Control(eng, ctrl_fail, ctrl_state=5):
+            X | qubit[0]
+
+        X | ctrl_success[0]
+        X | ctrl_success[2]
+        with Control(eng, ctrl_success, ctrl_state=5):
+            X | qubit[1]
+
+    All(Measure) | qubit
+    All(Measure) | ctrl_fail
+    All(Measure) | ctrl_success
+    eng.flush()
+    return qubit, ctrl_fail, ctrl_success
+
+
+if __name__ == '__main__':
+    # Create a MainEngine with a unitary simulator backend
+    eng = MainEngine()
+
+    # Run out quantum circuit
+    #   1 - Default behaviour of the control: all control qubits should be 1
+    #   2 - Off-control: all control qubits should remain 0
+    #   3 - Specific state given by a string
+    #   4 - Specific state given by an integer
+
+    qubit, ctrl_fail, ctrl_success = run_circuit(eng, 4)
+
+    # Measured value of the failed qubit should be 0 in all cases
+    print('The final value of the qubit with failed control is:')
+    print(int(qubit[0]))
+    print('with the state of control qubits are:')
+    print([int(qubit) for qubit in ctrl_fail], '\n')
+
+    # Measured value of the success qubit should be 1 in all cases
+    print('The final value of the qubit with successful control is:')
+    print(int(qubit[1]))
+    print('with the state of control qubits are:')
+    print([int(qubit) for qubit in ctrl_success], '\n')

projectq/backends/_aqt/_aqt_test.py

@@ -19,7 +19,7 @@
 
 from projectq import MainEngine
 from projectq.backends._aqt import _aqt
-from projectq.types import WeakQubitRef, Qubit
+from projectq.types import WeakQubitRef
 from projectq.cengines import DummyEngine, BasicMapperEngine
 from projectq.ops import (
     All,
@@ -140,6 +140,10 @@ def test_aqt_too_many_runs():
         Rx(math.pi / 2) | qubit
         eng.flush()
 
+    # Avoid exception at deletion
+    backend._num_runs = 1
+    backend._circuit = []
+
 
 def test_aqt_retrieve(monkeypatch):
     # patch send
@@ -171,7 +175,7 @@ def mock_retrieve(*args, **kwargs):
     assert prob_dict['00'] == pytest.approx(0.6)
 
     # Unknown qubit and no mapper
-    invalid_qubit = [Qubit(eng, 10)]
+    invalid_qubit = [WeakQubitRef(eng, 10)]
     with pytest.raises(RuntimeError):
         eng.backend.get_probabilities(invalid_qubit)
 
@@ -227,7 +231,7 @@ def mock_send(*args, **kwargs):
     assert prob_dict['00'] == pytest.approx(0.6)
 
     # Unknown qubit and no mapper
-    invalid_qubit = [Qubit(eng, 10)]
+    invalid_qubit = [WeakQubitRef(eng, 10)]
     with pytest.raises(RuntimeError):
         eng.backend.get_probabilities(invalid_qubit)
 

projectq/backends/_awsbraket/_awsbraket.py

@@ -18,7 +18,7 @@
 import json
 
 from projectq.cengines import BasicEngine
-from projectq.meta import get_control_count, LogicalQubitIDTag
+from projectq.meta import get_control_count, LogicalQubitIDTag, has_negative_control
 from projectq.types import WeakQubitRef
 from projectq.ops import (
     R,
@@ -176,6 +176,9 @@ def is_available(self, cmd):
         if gate in (Measure, Allocate, Deallocate, Barrier):
             return True
 
+        if has_negative_control(cmd):
+            return False
+
         if self.device == 'Aspen-8':
             if get_control_count(cmd) == 2:
                 return isinstance(gate, XGate)
@@ -271,21 +274,24 @@ def _store(self, cmd):
         Args:
             cmd: Command to store
         """
+        gate = cmd.gate
+
+        # Do not clear the self._clear flag for those gates
+        if gate in (Deallocate, Barrier):
+            return
+
+        num_controls = get_control_count(cmd)
+        gate_type = type(gate) if not isinstance(gate, DaggeredGate) else type(gate._gate)
+
         if self._clear:
             self._probabilities = dict()
             self._clear = False
             self._circuit = ""
             self._allocated_qubits = set()
 
-        gate = cmd.gate
-        num_controls = get_control_count(cmd)
-        gate_type = type(gate) if not isinstance(gate, DaggeredGate) else type(gate._gate)
-
         if gate == Allocate:
             self._allocated_qubits.add(cmd.qubits[0][0].id)
             return
-        if gate in (Deallocate, Barrier):
-            return
         if gate == Measure:
             assert len(cmd.qubits) == 1 and len(cmd.qubits[0]) == 1
             qb_id = cmd.qubits[0][0].id
@@ -412,6 +418,10 @@ def _run(self):
         # Also, AWS Braket currently does not support intermediate
         # measurements.
 
+        # If the clear flag is set, nothing to do here...
+        if self._clear:
+            return
+
         # In Braket the results for the jobs are stored in S3.
         # You can recover the results from previous jobs using the TaskArn
         # (self._retrieve_execution).

projectq/backends/_awsbraket/_awsbraket_boto3_client_test.py

@@ -15,7 +15,6 @@
 """ Test for projectq.backends._awsbraket._awsbraket_boto3_client.py """
 
 import pytest
-from unittest.mock import patch
 
 from ._awsbraket_boto3_client_test_fixtures import *  # noqa: F401,F403
 
@@ -34,13 +33,13 @@
 
 
 @has_boto3
-@patch('boto3.client')
-def test_show_devices(mock_boto3_client, show_devices_setup):
+def test_show_devices(mocker, show_devices_setup):
     creds, search_value, device_value, devicelist_result = show_devices_setup
 
-    mock_boto3_client.return_value = mock_boto3_client
+    mock_boto3_client = mocker.MagicMock(spec=['search_devices', 'get_device'])
     mock_boto3_client.search_devices.return_value = search_value
     mock_boto3_client.get_device.return_value = device_value
+    mocker.patch('boto3.client', return_value=mock_boto3_client, autospec=True)
 
     devicelist = _awsbraket_boto3_client.show_devices(credentials=creds)
     assert devicelist == devicelist_result
@@ -85,7 +84,6 @@ def test_show_devices(mock_boto3_client, show_devices_setup):
 
 
 @has_boto3
-@patch('boto3.client')
 @pytest.mark.parametrize(
     "var_status, var_result",
     [
@@ -95,13 +93,14 @@ def test_show_devices(mock_boto3_client, show_devices_setup):
         ('other', other_value),
     ],
 )
-def test_retrieve(mock_boto3_client, var_status, var_result, retrieve_setup):
+def test_retrieve(mocker, var_status, var_result, retrieve_setup):
     arntask, creds, device_value, res_completed, results_dict = retrieve_setup
 
-    mock_boto3_client.return_value = mock_boto3_client
+    mock_boto3_client = mocker.MagicMock(spec=['get_quantum_task', 'get_device', 'get_object'])
     mock_boto3_client.get_quantum_task.return_value = var_result
     mock_boto3_client.get_device.return_value = device_value
     mock_boto3_client.get_object.return_value = results_dict
+    mocker.patch('boto3.client', return_value=mock_boto3_client, autospec=True)
 
     if var_status == 'completed':
         res = _awsbraket_boto3_client.retrieve(credentials=creds, taskArn=arntask)
@@ -132,8 +131,7 @@ def test_retrieve(mock_boto3_client, var_status, var_result, retrieve_setup):
 
 
 @has_boto3
-@patch('boto3.client')
-def test_retrieve_devicetypes(mock_boto3_client, retrieve_devicetypes_setup):
+def test_retrieve_devicetypes(mocker, retrieve_devicetypes_setup):
     (
         arntask,
         creds,
@@ -142,10 +140,11 @@ def test_retrieve_devicetypes(mock_boto3_client, retrieve_devicetypes_setup):
         res_completed,
     ) = retrieve_devicetypes_setup
 
-    mock_boto3_client.return_value = mock_boto3_client
+    mock_boto3_client = mocker.MagicMock(spec=['get_quantum_task', 'get_device', 'get_object'])
     mock_boto3_client.get_quantum_task.return_value = completed_value
     mock_boto3_client.get_device.return_value = device_value
     mock_boto3_client.get_object.return_value = results_dict
+    mocker.patch('boto3.client', return_value=mock_boto3_client, autospec=True)
 
     res = _awsbraket_boto3_client.retrieve(credentials=creds, taskArn=arntask)
     assert res == res_completed
@@ -155,13 +154,13 @@ def test_retrieve_devicetypes(mock_boto3_client, retrieve_devicetypes_setup):
 
 
 @has_boto3
-@patch('boto3.client')
-def test_send_too_many_qubits(mock_boto3_client, send_too_many_setup):
+def test_send_too_many_qubits(mocker, send_too_many_setup):
     (creds, s3_folder, search_value, device_value, info_too_much) = send_too_many_setup
 
-    mock_boto3_client.return_value = mock_boto3_client
+    mock_boto3_client = mocker.MagicMock(spec=['search_devices', 'get_device'])
     mock_boto3_client.search_devices.return_value = search_value
     mock_boto3_client.get_device.return_value = device_value
+    mocker.patch('boto3.client', return_value=mock_boto3_client, autospec=True)
 
     with pytest.raises(_awsbraket_boto3_client.DeviceTooSmall):
         _awsbraket_boto3_client.send(info_too_much, device='name2', credentials=creds, s3_folder=s3_folder)
@@ -171,7 +170,6 @@ def test_send_too_many_qubits(mock_boto3_client, send_too_many_setup):
 
 
 @has_boto3
-@patch('boto3.client')
 @pytest.mark.parametrize(
     "var_status, var_result",
     [
@@ -181,7 +179,7 @@ def test_send_too_many_qubits(mock_boto3_client, send_too_many_setup):
         ('other', other_value),
     ],
 )
-def test_send_real_device_online_verbose(mock_boto3_client, var_status, var_result, real_device_online_setup):
+def test_send_real_device_online_verbose(mocker, var_status, var_result, real_device_online_setup):
 
     (
         qtarntask,
@@ -194,12 +192,15 @@ def test_send_real_device_online_verbose(mock_boto3_client, var_status, var_resu
         results_dict,
     ) = real_device_online_setup
 
-    mock_boto3_client.return_value = mock_boto3_client
+    mock_boto3_client = mocker.MagicMock(
+        spec=['search_devices', 'get_device', 'create_quantum_task', 'get_quantum_task', 'get_object']
+    )
     mock_boto3_client.search_devices.return_value = search_value
     mock_boto3_client.get_device.return_value = device_value
     mock_boto3_client.create_quantum_task.return_value = qtarntask
     mock_boto3_client.get_quantum_task.return_value = var_result
     mock_boto3_client.get_object.return_value = results_dict
+    mocker.patch('boto3.client', return_value=mock_boto3_client, autospec=True)
 
     # This is a ficticios situation because the job will be always queued
     # at the beginning. After that the status will change at some point in time
@@ -243,7 +244,6 @@ def test_send_real_device_online_verbose(mock_boto3_client, var_status, var_resu
 
 
 @has_boto3
-@patch('boto3.client')
 @pytest.mark.parametrize(
     "var_error",
     [
@@ -254,16 +254,17 @@ def test_send_real_device_online_verbose(mock_boto3_client, var_status, var_resu
         ('ValidationException'),
     ],
 )
-def test_send_that_errors_are_caught(mock_boto3_client, var_error, send_that_error_setup):
+def test_send_that_errors_are_caught(mocker, var_error, send_that_error_setup):
     creds, s3_folder, info, search_value, device_value = send_that_error_setup
 
-    mock_boto3_client.return_value = mock_boto3_client
+    mock_boto3_client = mocker.MagicMock(spec=['search_devices', 'get_device', 'create_quantum_task'])
     mock_boto3_client.search_devices.return_value = search_value
     mock_boto3_client.get_device.return_value = device_value
     mock_boto3_client.create_quantum_task.side_effect = botocore.exceptions.ClientError(
         {"Error": {"Code": var_error, "Message": "Msg error for " + var_error}},
         "create_quantum_task",
     )
+    mocker.patch('boto3.client', return_value=mock_boto3_client, autospec=True)
 
     with pytest.raises(botocore.exceptions.ClientError):
         _awsbraket_boto3_client.send(info, device='name2', credentials=creds, s3_folder=s3_folder, num_retries=2)
@@ -282,15 +283,15 @@ def test_send_that_errors_are_caught(mock_boto3_client, var_error, send_that_err
 
 
 @has_boto3
-@patch('boto3.client')
 @pytest.mark.parametrize("var_error", [('ResourceNotFoundException')])
-def test_retrieve_error_arn_not_exist(mock_boto3_client, var_error, arntask, creds):
+def test_retrieve_error_arn_not_exist(mocker, var_error, arntask, creds):
 
-    mock_boto3_client.return_value = mock_boto3_client
+    mock_boto3_client = mocker.MagicMock(spec=['get_quantum_task'])
     mock_boto3_client.get_quantum_task.side_effect = botocore.exceptions.ClientError(
         {"Error": {"Code": var_error, "Message": "Msg error for " + var_error}},
         "get_quantum_task",
     )
+    mocker.patch('boto3.client', return_value=mock_boto3_client, autospec=True)
 
     with pytest.raises(botocore.exceptions.ClientError):
         _awsbraket_boto3_client.retrieve(credentials=creds, taskArn=arntask)