Add a component class that allows access to its pre_act context dur…

…ing the `PRE_ACT` phase.

This is achieved by making the context ignore the action spec, and computing its context only once during the first time it is requested. Components that want their `pre_act` context available to other components should derive from this class.

PiperOrigin-RevId: 650012324
Change-Id: Ic63aaa84a997fa6ddd42ce01567e1bb8d2a697ab

concordia/components/agent/v2/__init__.py

@@ -14,6 +14,7 @@
 
 """Library of components specifically for generative agents."""
 
+from concordia.components.agent.v2 import action_spec_ignored
 from concordia.components.agent.v2 import constant
 from concordia.components.agent.v2 import legacy_act_component
 from concordia.components.agent.v2 import no_op_context_processor

concordia/components/agent/v2/action_spec_ignored.py

@@ -0,0 +1,63 @@
+# Copyright 2023 DeepMind Technologies Limited.
+#
+# 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
+#
+#     https://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.
+
+"""A component that ignores the action spec in the `pre_act` method."""
+
+import abc
+
+from concordia.typing import component_v2
+from concordia.typing import entity as entity_lib
+
+
+class ActionSpecIgnored(component_v2.EntityComponent, metaclass=abc.ABCMeta):
+  """A component that ignores the action spec in the `pre_act` method.
+  
+  As a consequence, its `pre_act` state can be accessed safely by other
+  components. This is useful for components that need to condition their
+  `pre_act` state on the state of other components. Derived classes should
+  implement `make_pre_act_context` instead of `pre_act`. The pre_act context
+  will be cached and returned by `get_pre_act_context` and `pre_act`, and
+  cleaned up by `update`.
+  """
+
+  def __init__(self):
+    """Initializes the component."""
+    self._pre_act_context: str | None = None
+
+  @abc.abstractmethod
+  def make_pre_act_context(self) -> str:
+    """Creates the pre-act context."""
+    raise NotImplementedError()
+
+  def set_pre_act_context(self, pre_act_context: str) -> None:
+    """Creates the pre-act context."""
+    if self._pre_act_context is not None:
+      raise ValueError('pre_act_context is already set.')
+    self._pre_act_context = pre_act_context
+
+  def get_pre_act_context(self) -> str:
+    """Creates the pre-act context."""
+    if self._pre_act_context is None:
+      self._pre_act_context = self.make_pre_act_context()
+    return self._pre_act_context
+
+  def pre_act(
+      self,
+      action_spec: entity_lib.ActionSpec,
+  ) -> str:
+    del action_spec
+    return self.get_pre_act_context()
+
+  def update(self) -> None:
+    self._pre_act_context = None

concordia/components/agent/v2/observation.py

@@ -17,13 +17,13 @@
 from collections.abc import Callable
 import datetime
 from concordia.associative_memory import associative_memory
-from concordia.typing import component_v2
-from concordia.typing import entity as entity_lib
+from concordia.components.agent.v2 import action_spec_ignored
 
+import overrides
 
-class Observation(component_v2.EntityComponent):
-  """A simple component to receive observations.
-  """
+
+class Observation(action_spec_ignored.ActionSpecIgnored):
+  """A simple component to receive observations."""
 
   def __init__(
       self,
@@ -45,10 +45,8 @@ def pre_observe(
     )
     return ''
 
-  def pre_act(
-      self,
-      unused_action_spec: entity_lib.ActionSpec,
-  ) -> str:
+  @overrides.overrides
+  def make_pre_act_context(self) -> str:
     mems = self._memory.retrieve_time_interval(
         self._clock_now() - self._timeframe, self._clock_now(), add_time=True
     )