Delete schedules (#2589)

- Delete cirq/schedules directory
- Remove Device.duration_of/validate_schedule/validate_scheduled_operation
- Remove all validate_schedule methods (but leave duration_of on specific devices for now)
- Remove all references to cirq.Schedule
- Maintain engine backwards compatibility by auto-converting to circuits in schedule contexts

Skipping deprecation because there's no reasonable way to half support schedules, and
this would tie us up for months bending over backwards for a feature we think
nobody uses.

Fixes #2478

cirq/__init__.py

@@ -38,7 +38,6 @@
 from cirq import (
     # Core
     circuits,
-    schedules,
     # Optimize and run
     optimizers,
     work,
@@ -299,12 +298,6 @@
     two_qubit_matrix_to_operations,
 )
 
-from cirq.schedules import (
-    moment_by_moment_schedule,
-    Schedule,
-    ScheduledOperation,
-)
-
 from cirq.sim import (
     bloch_vector_from_state_vector,
     StabilizerStateChForm,

cirq/aqt/aqt_sampler.py

@@ -25,14 +25,17 @@
 import json
 import time
 import uuid
-from typing import Iterable, List, Union, Tuple, Dict, cast
+from typing import Iterable, List, Union, Tuple, Dict, cast, TYPE_CHECKING
 
 import numpy as np
 from requests import put
 from cirq import circuits, Sampler, resolve_parameters, LineQubit
 from cirq.study.sweeps import Sweep
 from cirq.aqt.aqt_device import AQTSimulator, get_op_string
-from cirq import study, ops, schedules, IonDevice
+from cirq import study, ops, IonDevice
+
+if TYPE_CHECKING:
+    import cirq
 
 Sweepable = Union[study.ParamResolver, Iterable[study.ParamResolver], Sweep,
                   Iterable[Sweep]]
@@ -168,16 +171,16 @@ def _send_json(self,
         return measurements
 
     def run_sweep(self,
-                  program: Union[circuits.Circuit, schedules.Schedule],
+                  program: 'cirq.Circuit',
                   params: study.Sweepable,
                   repetitions: int = 1) -> List[study.TrialResult]:
-        """Samples from the given Circuit or Schedule.
+        """Samples from the given Circuit.
 
         In contrast to run, this allows for sweeping over different parameter
         values.
 
         Args:
-            program: The circuit or schedule to simulate.
+            program: The circuit to simulate.
             Should be generated using AQTSampler.generate_circuit_from_list
             params: Parameters to run with the program.
             repetitions: The number of repetitions to simulate.
@@ -187,14 +190,12 @@ def run_sweep(self,
             resolver.
         """
         meas_name = 'm'  # TODO: Get measurement name from circuit. Issue #2195
-        circuit = (program.to_circuit()
-                   if isinstance(program, schedules.Schedule) else program)
-        assert isinstance(circuit.device, IonDevice)
+        assert isinstance(program.device, IonDevice)
         trial_results = []  # type: List[study.TrialResult]
         for param_resolver in study.to_resolvers(params):
             id_str = uuid.uuid1()
-            num_qubits = len(circuit.device.qubits)
-            json_str = self._generate_json(circuit=circuit,
+            num_qubits = len(program.device.qubits)
+            json_str = self._generate_json(circuit=program,
                                            param_resolver=param_resolver)
             results = self._send_json(json_str=json_str,
                                       id_str=id_str,

cirq/circuits/circuit_test.py

@@ -37,15 +37,6 @@ def validate_moment(self, moment):
             raise ValueError('not isinstance({!r}, {!r})'.format(
                 moment, cirq.Moment))
 
-    def duration_of(self, operation):
-        return cirq.Duration(picos=0) # coverage: ignore
-
-    def validate_schedule(self, schedule):
-        pass
-
-    def validate_scheduled_operation(self, schedule, scheduled_operation):
-        pass
-
 
 moment_and_op_type_validating_device = _MomentAndOpTypeValidatingDeviceType()
 
@@ -125,22 +116,9 @@ def test_approx_eq():
 
     class TestDevice(cirq.Device):
 
-        def duration_of(self, operation: cirq.Operation) -> cirq.Duration:
-            pass
-
         def validate_operation(self, operation: cirq.Operation) -> None:
             pass
 
-        def validate_scheduled_operation(
-                self,
-                schedule: cirq.Schedule,
-                scheduled_operation: cirq.ScheduledOperation
-        ) -> None:
-            pass
-
-        def validate_schedule(self, schedule: 'cirq.Schedule') -> None:
-            pass
-
     a = cirq.NamedQubit('a')
     b = cirq.NamedQubit('b')
 

cirq/contrib/acquaintance/devices.py

@@ -16,7 +16,7 @@
 
 import abc
 
-from cirq import circuits, devices, ops, schedules
+from cirq import circuits, devices, ops
 from cirq.contrib.acquaintance.gates import (
     AcquaintanceOpportunityGate, SwapNetworkGate)
 from cirq.contrib.acquaintance.bipartite import (
@@ -31,12 +31,7 @@
 
 
 class AcquaintanceDevice(devices.Device, metaclass=abc.ABCMeta):
-    """A device that contains only acquaintance and permutation gates.
-
-    Raises:
-        NotImplementedError: Any of the schedule-related methods (duration_of,
-            validate_schedule[d_operation]) is called.
-    """
+    """A device that contains only acquaintance and permutation gates."""
     gate_types = (AcquaintanceOpportunityGate, PermutationGate)
 
     def validate_operation(self, operation: 'cirq.Operation') -> None:
@@ -47,20 +42,6 @@ def validate_operation(self, operation: 'cirq.Operation') -> None:
                           'ininstance({0!r}.gate, {2!r})'.format(
                         operation, ops.Operation, self.gate_types))
 
-    def duration_of(self, operation):
-        raise NotImplementedError()
-
-    def validate_scheduled_operation(
-            self,
-            schedule: schedules.Schedule,
-            scheduled_operation: schedules.ScheduledOperation
-    ) -> None:
-        raise NotImplementedError()
-
-
-    def validate_schedule(self, schedule: schedules.Schedule) -> None:
-        raise NotImplementedError()
-
 
 def is_acquaintance_strategy(circuit: 'cirq.Circuit'):
     return isinstance(circuit._device, AcquaintanceDevice)

cirq/contrib/graph_device/graph_device.py

@@ -17,7 +17,7 @@
 
 from typing import Iterable, Optional
 
-from cirq import devices, ops, value, schedules
+from cirq import devices, ops, value
 
 from cirq.contrib.graph_device.hypergraph import UndirectedHypergraph
 
@@ -196,21 +196,6 @@ def validate_moment(self, moment: ops.Moment):
             other_ops = ops[:i] + ops[i + 1:]
             self.validate_crosstalk(op, other_ops)
 
-    def validate_scheduled_operation(
-            self, schedule: schedules.Schedule,
-            scheduled_operation: schedules.ScheduledOperation) -> None:
-        operation = scheduled_operation.operation
-        self.validate_operation(operation)
-
-        other_operations = (
-            scheduled_operation.operation for scheduled_operation in
-            schedule.operations_happening_at_same_time_as(scheduled_operation))
-        self.validate_crosstalk(operation, other_operations)
-
-    def validate_schedule(self, schedule: schedules.Schedule) -> None:
-        for scheduled_operation in schedule.scheduled_operations:
-            self.validate_scheduled_operation(schedule, scheduled_operation)
-
     def __eq__(self, other):
         return ((self.device_graph == other.device_graph) and
                 (self.crosstalk_graph == other.crosstalk_graph))

cirq/contrib/graph_device/graph_device_test.py

@@ -148,30 +148,17 @@ def not_cnots(first_op, second_op):
     moment = cirq.Moment([cirq.CNOT(*qubits[:2]), cirq.CNOT(*qubits[2:])])
     with pytest.raises(ValueError):
         graph_device.validate_moment(moment)
-    with pytest.raises(ValueError):
-        scheduled_operations = (cirq.ScheduledOperation.op_at_on(
-            op, cirq.Timestamp(), graph_device) for op in moment.operations)
-        schedule = cirq.Schedule(graph_device, scheduled_operations)
-        graph_device.validate_schedule(schedule)
 
     moment = cirq.Moment(
         [cirq.CNOT(qubits[0], qubits[3]),
          cirq.CZ(qubits[1], qubits[2])])
     graph_device.validate_moment(moment)
-    circuit = cirq.Circuit(moment, device=graph_device)
-    schedule = cirq.moment_by_moment_schedule(graph_device, circuit)
-    assert graph_device.validate_schedule(schedule) is None
 
     moment = cirq.Moment(
         [cirq.CNOT(qubits[0], qubits[3]),
          cirq.CNOT(qubits[1], qubits[2])])
     with pytest.raises(ValueError):
         graph_device.validate_moment(moment)
-    with pytest.raises(ValueError):
-        scheduled_operations = (cirq.ScheduledOperation.op_at_on(
-            op, cirq.Timestamp(), graph_device) for op in moment.operations)
-        schedule = cirq.Schedule(graph_device, scheduled_operations)
-        graph_device.validate_schedule(schedule)
 
 
 def test_graph_device_copy_and_add():

cirq/contrib/noise_models/noise_models_test.py

@@ -23,16 +23,14 @@
 
 def test_moment_is_measurements():
     q = cirq.LineQubit.range(2)
-    circ = cirq.Circuit.from_ops(
-        [cirq.X(q[0]), cirq.X(q[1]),
-         cirq.measure(*q, key='z')])
+    circ = cirq.Circuit([cirq.X(q[0]), cirq.X(q[1]), cirq.measure(*q, key='z')])
     assert not _homogeneous_moment_is_measurements(circ[0])
     assert _homogeneous_moment_is_measurements(circ[1])
 
 
 def test_moment_is_measurements_mixed1():
     q = cirq.LineQubit.range(2)
-    circ = cirq.Circuit.from_ops([
+    circ = cirq.Circuit([
         cirq.X(q[0]),
         cirq.X(q[1]),
         cirq.measure(q[0], key='z'),
@@ -46,7 +44,7 @@ def test_moment_is_measurements_mixed1():
 
 def test_moment_is_measurements_mixed2():
     q = cirq.LineQubit.range(2)
-    circ = cirq.Circuit.from_ops([
+    circ = cirq.Circuit([
         cirq.X(q[0]),
         cirq.X(q[1]),
         cirq.Z(q[0]),

cirq/devices/device.py

@@ -16,8 +16,6 @@
 
 import abc
 
-from cirq.value import Duration
-
 
 if TYPE_CHECKING:
     import cirq
@@ -26,7 +24,7 @@
 
 
 class Device(metaclass=abc.ABCMeta):
-    """Hardware constraints for validating circuits and schedules."""
+    """Hardware constraints for validating circuits."""
 
     def decompose_operation(self, operation: 'cirq.Operation'
                             ) -> 'cirq.OP_TREE':
@@ -38,10 +36,6 @@ def decompose_operation(self, operation: 'cirq.Operation'
         """
         return operation
 
-    @abc.abstractmethod
-    def duration_of(self, operation: 'cirq.Operation') -> Duration:
-        pass
-
     @abc.abstractmethod
     def validate_operation(self, operation: 'cirq.Operation') -> None:
         """Raises an exception if an operation is not valid.
@@ -53,23 +47,6 @@ def validate_operation(self, operation: 'cirq.Operation') -> None:
             ValueError: The operation isn't valid for this device.
         """
 
-    @abc.abstractmethod
-    def validate_scheduled_operation(
-            self,
-            schedule: 'cirq.Schedule',
-            scheduled_operation: 'cirq.ScheduledOperation'
-    ) -> None:
-        """Raises an exception if the scheduled operation is not valid.
-
-        Args:
-            schedule: The schedule to validate against.
-            scheduled_operation: The scheduled operation to validate.
-
-        Raises:
-            ValueError: If the scheduled operation is not valid for the
-                schedule.
-        """
-
     def validate_circuit(self, circuit: 'cirq.Circuit') -> None:
         """Raises an exception if a circuit is not valid.
 
@@ -110,14 +87,3 @@ def can_add_operation_into_moment(self,
             Whether or not the moment will validate after adding the operation.
         """
         return not moment.operates_on(operation.qubits)
-
-    @abc.abstractmethod
-    def validate_schedule(self, schedule: 'cirq.Schedule') -> None:
-        """Raises an exception if a schedule is not valid.
-
-        Args:
-            schedule: The schedule to validate.
-
-        Raises:
-            ValueError: The schedule isn't valid for this device.
-        """

cirq/devices/unconstrained_device.py

@@ -27,18 +27,12 @@ def duration_of(self, operation):
     def validate_operation(self, operation):
         pass
 
-    def validate_scheduled_operation(self, schedule, scheduled_operation):
-        pass
-
     def validate_moment(self, moment):
         pass
 
     def validate_circuit(self, circuit):
         pass
 
-    def validate_schedule(self, schedule):
-        pass
-
     def __repr__(self):
         return 'cirq.UNCONSTRAINED_DEVICE'
 

cirq/experiments/single_qubit_readout_calibration_test.py

@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from typing import List, Union
+from typing import List
 
 import numpy as np
 
@@ -39,7 +39,7 @@ def __init__(self,
 
     def run_sweep(
             self,
-            program: Union[cirq.Circuit, cirq.Schedule],
+            program: 'cirq.Circuit',
             params: cirq.Sweepable,
             repetitions: int = 1,
     ) -> List[cirq.TrialResult]:

cirq/google/__init__.py

@@ -24,8 +24,8 @@
     is_native_xmon_gate,
     is_native_xmon_op,
     pack_results,
-    schedule_from_proto_dicts,
-    schedule_to_proto_dicts,
+    circuit_as_schedule_to_proto_dicts,
+    circuit_from_schedule_from_proto_dicts,
     unpack_results,
     xmon_op_from_proto_dict,
 )

cirq/google/api/v1/__init__.py

@@ -27,8 +27,8 @@
     is_native_xmon_gate,
     is_native_xmon_op,
     pack_results,
-    schedule_from_proto_dicts,
-    schedule_to_proto_dicts,
+    circuit_as_schedule_to_proto_dicts,
+    circuit_from_schedule_from_proto_dicts,
     unpack_results,
     xmon_op_from_proto_dict,
 )