openstack
/
automaton
Code Issues Proposed changes

Document `process_event` return and expose return namedtuple type 

Change-Id: I50f4695dd24c7f1f947a77b66b871360d2271e91
This commit is contained in:
Joshua Harlow 2015-06-30 14:48:18 -07:00
parent f511ea9f94
commit c6989a0867
1 changed files with 23 additions and 12 deletions
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35
automaton/machines.py
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@ -59,17 +59,18 @@ class FiniteMachine(object):
transition. The other way to use this
state machine is to skip using :py:meth:`~automaton.runners.Runner.run`
or :py:meth:`~automaton.runners.Runner.run_iter`
completely and use the :meth:`.process_event` method explicitly and
trigger the events via some *external* functionality/triggers...
completely and use the :meth:`~.FiniteMachine.process_event` method
explicitly and trigger the events via
some *external* functionality/triggers...
"""
# Result of processing an event (cause and effect...)
_Effect = collections.namedtuple('_Effect', 'reaction,terminal')
#: The result of processing an event (cause and effect...)
Effect = collections.namedtuple('Effect', 'reaction,terminal')
@classmethod
def _effect_builder(cls, new_state, event):
return cls._Effect(new_state['reactions'].get(event),
new_state["terminal"])
return cls.Effect(new_state['reactions'].get(event),
new_state["terminal"])
@removals.removed_kwarg('default_start_state',
message="The usage of 'default_start_state' via"
@ -215,7 +216,17 @@ class FiniteMachine(object):
return result
def process_event(self, event):
"""Trigger a state change in response to the provided event."""
"""Trigger a state change in response to the provided event.
:returns: Effect this is either a :py:class:`.FiniteMachine.Effect` or
an ``Effect`` from a subclass of :py:class:`.FiniteMachine`.
See the appropriate named tuple for a description of the
actual items in the tuple. For
example, :py:class:`.FiniteMachine.Effect`'s
first item is ``reaction``: one could invoke this reaction's
callback to react to the new stable state.
:rtype: namedtuple
"""
self._pre_process_event(event)
current = self._current
replacement = self._transitions[current.name][event]
@ -350,9 +361,9 @@ class FiniteMachine(object):
class HierarchicalFiniteMachine(FiniteMachine):
"""A fsm that understands how to run in a hierarchical mode."""
# Result of processing an event (cause and effect...)
_Effect = collections.namedtuple('_Effect',
'reaction,terminal,machine')
#: The result of processing an event (cause and effect...)
Effect = collections.namedtuple('Effect',
'reaction,terminal,machine')
def __init__(self, default_start_state=None):
super(HierarchicalFiniteMachine, self).__init__(
@ -361,8 +372,8 @@ class HierarchicalFiniteMachine(FiniteMachine):
@classmethod
def _effect_builder(cls, new_state, event):
return cls._Effect(new_state['reactions'].get(event),
new_state["terminal"], new_state.get('machine'))
return cls.Effect(new_state['reactions'].get(event),
new_state["terminal"], new_state.get('machine'))
def add_state(self, state,
terminal=False, on_enter=None, on_exit=None, machine=None):