Remove BooleanHamiltonian object (quantumlib#5099)

Now that v0.14 is released, delete deprecate object

Author: tonybruguier

cirq-core/cirq/__init__.py

@@ -196,7 +196,6 @@
     BaseDensePauliString,
     bit_flip,
     BitFlipChannel,
-    BooleanHamiltonian,
     BooleanHamiltonianGate,
     CCX,
     CCXPowGate,

cirq-core/cirq/json_resolver_cache.py

@@ -33,6 +33,11 @@ def _class_resolver_dictionary() -> Dict[str, ObjectFactory]:
     from cirq.experiments import CrossEntropyResult, CrossEntropyResultDict, GridInteractionLayer
     from cirq.experiments.grid_parallel_two_qubit_xeb import GridParallelXEBMetadata
 
+    def _boolean_hamiltonian_gate_op(qubit_map, boolean_strs, theta):
+        return cirq.BooleanHamiltonianGate(
+            parameter_names=list(qubit_map.keys()), boolean_strs=boolean_strs, theta=theta
+        ).on(*qubit_map.values())
+
     def _identity_operation_from_dict(qubits, **kwargs):
         return cirq.identity_each(*qubits)
 
@@ -58,7 +63,6 @@ def _parallel_gate_op(gate, qubits):
         'AsymmetricDepolarizingChannel': cirq.AsymmetricDepolarizingChannel,
         'BitFlipChannel': cirq.BitFlipChannel,
         'BitstringAccumulator': cirq.work.BitstringAccumulator,
-        'BooleanHamiltonian': cirq.BooleanHamiltonian,
         'BooleanHamiltonianGate': cirq.BooleanHamiltonianGate,
         'CCNotPowGate': cirq.CCNotPowGate,
         'CCXPowGate': cirq.CCXPowGate,
@@ -186,6 +190,7 @@ def _parallel_gate_op(gate, qubits):
         'ZPowGate': cirq.ZPowGate,
         'ZZPowGate': cirq.ZZPowGate,
         # Old types, only supported for backwards-compatibility
+        'BooleanHamiltonian': _boolean_hamiltonian_gate_op,  # Removed in v0.15
         'IdentityOperation': _identity_operation_from_dict,
         'ParallelGateOperation': _parallel_gate_op,  # Removed in v0.14
         'SingleQubitMatrixGate': single_qubit_matrix_gate,

cirq-core/cirq/ops/__init__.py

@@ -31,7 +31,6 @@
 )
 
 from cirq.ops.boolean_hamiltonian import (
-    BooleanHamiltonian,
     BooleanHamiltonianGate,
 )
 

cirq-core/cirq/ops/boolean_hamiltonian.py

@@ -30,106 +30,10 @@
 
 import cirq
 from cirq import value
-from cirq._compat import deprecated_class
 from cirq.ops import raw_types
 from cirq.ops.linear_combinations import PauliSum, PauliString
 
 
-@deprecated_class(deadline='v0.15', fix='Use cirq.BooleanHamiltonianGate')
-@value.value_equality
-class BooleanHamiltonian(raw_types.Operation):
-    """An operation that represents a Hamiltonian from a set of Boolean functions."""
-
-    def __init__(
-        self,
-        qubit_map: Dict[str, 'cirq.Qid'],
-        boolean_strs: Sequence[str],
-        theta: float,
-    ):
-        """Builds a BooleanHamiltonian.
-
-        For each element of a sequence of Boolean expressions, the code first transforms it into a
-        polynomial of Pauli Zs that represent that particular expression. Then, we sum all the
-        polynomials, thus making a function that goes from a series to Boolean inputs to an integer
-        that is the number of Boolean expressions that are true.
-
-        For example, if we were using this gate for the unweighted max-cut problem that is typically
-        used to demonstrate the QAOA algorithm, there would be one Boolean expression per edge. Each
-        Boolean expression would be true iff the vertices on that are in different cuts (i.e. it's)
-        an XOR.
-
-        Then, we compute exp(-j * theta * polynomial), which is unitary because the polynomial is
-        Hermitian.
-
-        Args:
-            boolean_strs: The list of Sympy-parsable Boolean expressions.
-            qubit_map: map of string (boolean variable name) to qubit.
-            theta: The evolution time (angle) for the Hamiltonian
-
-        Raises:
-            ValueError: If the any qubits are not 2D.
-        """
-        if any(q.dimension != 2 for q in qubit_map.values()):
-            raise ValueError('All qubits must be 2-dimensional.')
-        self._qubit_map: Dict[str, 'cirq.Qid'] = qubit_map
-        self._boolean_strs: Sequence[str] = boolean_strs
-        self._theta: float = theta
-
-    def with_qubits(self, *new_qubits: 'cirq.Qid') -> 'BooleanHamiltonian':
-        if len(self._qubit_map) != len(new_qubits):
-            raise ValueError('Length of replacement qubits must be the same')
-        new_qubit_map = {
-            variable_name: new_qubit
-            for variable_name, new_qubit in zip(self._qubit_map, new_qubits)
-        }
-        return BooleanHamiltonian(
-            new_qubit_map,
-            self._boolean_strs,
-            self._theta,
-        )
-
-    @property
-    def qubits(self) -> Tuple[raw_types.Qid, ...]:
-        return tuple(self._qubit_map.values())
-
-    def num_qubits(self) -> int:
-        return len(self._qubit_map)
-
-    def _value_equality_values_(self):
-        return self._qubit_map, self._boolean_strs, self._theta
-
-    def _json_dict_(self) -> Dict[str, Any]:
-        return {
-            'qubit_map': self._qubit_map,
-            'boolean_strs': self._boolean_strs,
-            'theta': self._theta,
-        }
-
-    @classmethod
-    def _from_json_dict_(cls, qubit_map, boolean_strs, theta, **kwargs):
-        return cls(qubit_map, boolean_strs, theta)
-
-    def _decompose_(self):
-        boolean_exprs = [sympy_parser.parse_expr(boolean_str) for boolean_str in self._boolean_strs]
-        hamiltonian_polynomial_list = [
-            PauliSum.from_boolean_expression(boolean_expr, self._qubit_map)
-            for boolean_expr in boolean_exprs
-        ]
-
-        return _get_gates_from_hamiltonians(
-            hamiltonian_polynomial_list, self._qubit_map, self._theta
-        )
-
-    def _has_unitary_(self):
-        return True
-
-    @property
-    def gate(self) -> 'cirq.Gate':
-        return BooleanHamiltonianGate(
-            tuple(self._qubit_map.keys()), self._boolean_strs, self._theta
-        )
-
-
 @value.value_equality
 class BooleanHamiltonianGate(raw_types.Gate):
     """A gate that represents a Hamiltonian from a set of Boolean functions."""

cirq-core/cirq/ops/boolean_hamiltonian_test.py

@@ -53,8 +53,7 @@
         '(x2 | x1) ^ x0',
     ],
 )
-@pytest.mark.parametrize('transform', [lambda op: op, lambda op: op.gate.on(*op.qubits)])
-def test_circuit(boolean_str, transform):
+def test_circuit(boolean_str):
     boolean_expr = sympy_parser.parse_expr(boolean_str)
     var_names = cirq.parameter_names(boolean_expr)
     qubits = [cirq.NamedQubit(name) for name in var_names]
@@ -73,14 +72,13 @@ def test_circuit(boolean_str, transform):
     circuit = cirq.Circuit()
     circuit.append(cirq.H.on_each(*qubits))
 
-    with cirq.testing.assert_deprecated('Use cirq.BooleanHamiltonianGate', deadline='v0.15'):
-        hamiltonian_gate = cirq.BooleanHamiltonian(
-            {q.name: q for q in qubits}, [boolean_str], 0.1 * math.pi
-        )
+    hamiltonian_gate = cirq.BooleanHamiltonianGate(
+        {q.name: q for q in qubits}, [boolean_str], 0.1 * math.pi
+    )
 
     assert hamiltonian_gate.num_qubits() == n
 
-    circuit.append(transform(hamiltonian_gate))
+    circuit.append(hamiltonian_gate.on(*qubits))
 
     phi = cirq.Simulator().simulate(circuit, qubit_order=qubits, initial_state=0).state_vector()
     actual = np.arctan2(phi.real, phi.imag) - math.pi / 2.0 > 0.0
@@ -89,28 +87,6 @@ def test_circuit(boolean_str, transform):
     np.testing.assert_array_equal(actual, expected)
 
 
-def test_with_custom_names():
-    q0, q1, q2, q3 = cirq.LineQubit.range(4)
-    with cirq.testing.assert_deprecated(
-        'Use cirq.BooleanHamiltonianGate', deadline='v0.15', count=3
-    ):
-        original_op = cirq.BooleanHamiltonian(
-            {'a': q0, 'b': q1},
-            ['a'],
-            0.1,
-        )
-        assert cirq.decompose(original_op) == [cirq.Rz(rads=-0.05).on(q0)]
-
-        renamed_op = original_op.with_qubits(q2, q3)
-        assert cirq.decompose(renamed_op) == [cirq.Rz(rads=-0.05).on(q2)]
-
-        with pytest.raises(ValueError, match='Length of replacement qubits must be the same'):
-            original_op.with_qubits(q2)
-
-        with pytest.raises(ValueError, match='All qubits must be 2-dimensional'):
-            original_op.with_qubits(q0, cirq.LineQid(1, 3))
-
-
 def test_gate_with_custom_names():
     q0, q1, q2, q3 = cirq.LineQubit.range(4)
     gate = cirq.BooleanHamiltonianGate(

cirq-core/cirq/protocols/json_test_data/BooleanHamiltonian.json renamed to cirq-core/cirq/protocols/json_test_data/BooleanHamiltonian.json_inward

@@ -0,0 +1 @@
+[cirq.BooleanHamiltonianGate(parameter_names=['q0'], boolean_strs=['q0'], theta=0.20160913).on(cirq.NamedQubit('q0'))]

cirq-core/cirq/protocols/json_test_data/BooleanHamiltonian.repr

@@ -190,7 +190,6 @@
     ],
     deprecated={
         'GlobalPhaseOperation': 'v0.16',
-        'BooleanHamiltonian': 'v0.15',
         'SymmetricalQidPair': 'v0.15',
     },
     tested_elsewhere=[