fix: some cleaning

src/qibo/models/circuit.py

@@ -673,16 +673,6 @@ def add(self, gate):
                             raise_error(
                                 KeyError, f"Register {name} already exists in circuit."
                             )
-                    """
-                    registers = self.measurement_tuples
-                    for register, qubits in registers.items():
-                        intersection = set(qubits).intersection(set(gate.target_qubits))
-                        if len(intersection) > 0:
-                            raise_error(
-                                KeyError,
-                                f"Qubits {tuple(intersection)} already measured in register `{register}`.",
-                            )
-                    """
 
                 gate.result.circuit = self
                 if gate.collapse:

src/qibo/result.py

@@ -177,7 +177,6 @@ def __init__(
         self.nshots = nshots
 
         self._measurement_gate = None
-        self._measurement_registers = None
         self._probs = probabilities
         self._samples = samples
         self._frequencies = None
@@ -256,8 +255,8 @@ def frequencies(self, binary: bool = True, registers: bool = False):
 
         if registers:
             return {
-                register: gate.result.frequencies(binary)
-                for register, gate in self._measurement_registers
+                gate.register_name: gate.result.frequencies(binary)
+                for gate in self.measurements
             }
 
         if binary:
@@ -363,8 +362,8 @@ def samples(self, binary: bool = True, registers: bool = False):
 
         if registers:
             return {
-                register: gate.result.samples(binary)
-                for register, gate in self._measurement_registers
+                gate.register_name: gate.result.samples(binary)
+                for gate in self.measurements
             }
 
         if binary:
@@ -389,18 +388,6 @@ def measurement_gate(self):
 
         return self._measurement_gate
 
-    def measurement_registers(self):
-        if self._measurement_registers is None:
-            registers = {}
-            for gate in self.measurements:
-                if gate.register_name in registers:
-                    registers[gate.register_name].add(gate)
-                else:
-                    registers[gate.register_name] = gate
-            self._measurement_registers = registers
-
-        return self._measurement_registers
-
     def apply_bitflips(self, p0: float, p1: Optional[float] = None):
         """Apply bitflips to the measurements with probabilities `p0` and `p1`
 

tests/test_result.py

@@ -40,19 +40,6 @@ def test_measurementoutcomes_probabilities(backend, qubits):
         backend.assert_allclose(result.probabilities(qubits), probabilities, atol=1e-1)
 
 
-def test_measurementoutcomes_measurement_registers(backend):
-    c = Circuit(3)
-    c.add(gates.H(0))
-    c_copy = c.copy()
-    c.add(gates.M(0, register_name="m0"))
-    c.add(gates.M(2, register_name="m0"))
-    c_copy.add(gates.M(0, 2, register_name="m0"))
-    res = backend.execute_circuit(c)
-    res_copy = backend.execute_circuit(c_copy)
-    samples = res.samples(registers=True)
-    samples_copy = res_copy.samples(registers=True)
-
-
 def test_circuit_result_error(backend):
     c = models.Circuit(1)
     state = np.array([1, 0])