sum of two qcircuit

qlasskit/qcircuit/gates.py

@@ -83,11 +83,11 @@ def __init__(self, gate, n_controls):
 def apply(gate: QGate, qubits: List[int], param=None):
     if len(qubits) != gate.n_qubits:
         raise Exception(f"expected {gate.n_qubits} qubits ({len(qubits)} given)")
-    return [gate, qubits, param]
+    return (
+        gate,
+        qubits,
+        param,
+    )
 
 
 AppliedGate = Tuple[QGate, List[int], Any]
-
-# qc.append(CX(), [0, 1])
-# qc += apply(CX(), [0, 1])
-# qc += another_circ

qlasskit/qcircuit/qcircuit.py

@@ -6,12 +6,14 @@
 
 # http://www.apache.org/licenses/LICENSE-2.0
 
+import copy
+
 # 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 typing import Any, List, Literal, Union
+from typing import Any, List, Literal, Tuple, Union
 
 from sympy import Symbol
 
@@ -78,7 +80,28 @@ def __getitem__(self, key: Union[str, Symbol, int]):
 
     def __add__(self, qc: "QCircuit") -> "QCircuit":
         """Create a new QCircuit that merges two"""
-        raise Exception("not implemented")
+        nqc = copy.deepcopy(self)
+        nqc += qc
+        return nqc
+
+    def __iadd__(self, other: Union[gates.AppliedGate, "QCircuit"]):  # type: ignore
+        """AugAssign between a qcircuit and a AppliedGate|QCircuit"""
+        if isinstance(other, Tuple):  # type: ignore
+            self.append(other[0], other[1], other[2])
+        elif isinstance(other, QCircuit):  # type: ignore
+            if other.num_qubits > self.num_qubits:
+                raise Exception(
+                    f"Other circuit has too many qubits {other.num_qubits} > {self.num_qubits}"
+                )
+
+            self.gates.extend(other.gates)
+            self.gates_computed.extend(other.gates_computed)
+
+            for s, q in other.qubit_map.items():
+                if s not in self.qubit_map:
+                    self.qubit_map[s] = q
+
+        return self
 
     def add_qubit(self, name=None):
         """Add a qubit to the circuit.

test/test_qcircuit.py

@@ -36,7 +36,7 @@ def test_base_mapping(self):
         qc.ccx("a", Symbol("b"), c)
         self.assertEqual(qc.num_qubits, 3)
         self.assertTrue(isinstance(qc.gates[0][0], gates.CCX))
-        self.assertEqual(qc.gates[0][1:], [[0, 1, 2], None])
+        self.assertEqual(qc.gates[0][1:], ([0, 1, 2], None))
 
     def test_duplicate_qubit(self):
         qc = QCircuit()
@@ -47,6 +47,17 @@ def test_mapping(self):
         qc = QCircuit(4)
         qc.ccx("q0", "q1", "q2")
 
+    def test_augassign(self):
+        qc = QCircuit(1)
+        qc += gates.apply(gates.X(), [0])
+
+    def test_augassign_othercirc(self):
+        qc = QCircuit(1)
+        qc += gates.apply(gates.X(), [0])
+
+        qc2 = QCircuit(1)
+        qc2 += qc
+
     def test_get_key_by_index(self):
         qc = QCircuit()
         a, b = qc.add_qubit("a"), qc.add_qubit("b")