def _back_to_the_future(
tracker: DialogueStateTracker,
again: bool = False) -> Optional[DialogueStateTracker]:
"""Send Marty to the past to get
the new featurization for the future"""
idx_of_first_action = None
idx_of_second_action = None
# we need to find second executed action
for e_i, event in enumerate(tracker.applied_events()):
# find second ActionExecuted
if isinstance(event, ActionExecuted):
if idx_of_first_action is None:
idx_of_first_action = e_i
else:
idx_of_second_action = e_i
break
# use first action, if we went first time and second action, if we went again
idx_to_use = idx_of_second_action if again else idx_of_first_action
if idx_to_use is None:
return
# make second ActionExecuted the first one
events = tracker.applied_events()[idx_to_use:]
if not events:
return
mcfly_tracker = tracker.init_copy()
for e in events:
mcfly_tracker.update(e)
return mcfly_tracker
def _strip_leading_events_until_action_executed(
tracker: DialogueStateTracker,
again: bool = False) -> Optional[DialogueStateTracker]:
"""Truncates the tracker to begin at the next `ActionExecuted` event.
Args:
tracker: The tracker to truncate.
again: When true, truncate tracker at the second action.
Otherwise truncate to the first action.
Returns:
The truncated tracker if there were actions present.
If none are found, returns `None`.
"""
idx_of_first_action = None
idx_of_second_action = None
applied_events = tracker.applied_events()
# we need to find second executed action
for e_i, event in enumerate(applied_events):
if isinstance(event, ActionExecuted):
if idx_of_first_action is None:
idx_of_first_action = e_i
else:
idx_of_second_action = e_i
break
# use first action, if we went first time and second action, if we went again
idx_to_use = idx_of_second_action if again else idx_of_first_action
if idx_to_use is None:
return None
# make second ActionExecuted the first one
events = applied_events[idx_to_use:]
if not events:
return None
truncated_tracker = tracker.init_copy()
for e in events:
truncated_tracker.update(e)
return truncated_tracker
def _trim_tracker_by_max_history(
tracker: DialogueStateTracker, max_history: Optional[int],
) -> DialogueStateTracker:
"""Removes events from the tracker until it has `max_history` actions.
Args:
tracker: Some tracker.
max_history: Number of actions to keep.
Returns:
A new tracker with up to `max_history` actions, or the same tracker if
`max_history` is `None`.
"""
max_applied_events = _get_max_applied_events_for_max_history(tracker, max_history)
if not max_applied_events:
return tracker
applied_events = tracker.applied_events()[-max_applied_events:]
new_tracker = tracker.init_copy()
for event in applied_events:
new_tracker.update(event)
return new_tracker
def test_tracker_init_copy(default_domain: Domain):
sender_id = "some-id"
tracker = DialogueStateTracker(sender_id, default_domain.slots)
tracker_copy = tracker.init_copy()
assert tracker.sender_id == tracker_copy.sender_id
