yasmin.state_machine.StateMachine Class Reference

Inheritance diagram for yasmin.state_machine.StateMachine:

Collaboration diagram for yasmin.state_machine.StateMachine:

Public Member Functions
None	__init__ (self, Set[str] outcomes)
None	add_state (self, str name, State state, Dict[str, str] transitions=None)
None	set_start_state (self, str state_name)
str	get_start_state (self)
Dict[str, Union[State, Dict[str, str]]]	get_states (self)
str	get_current_state (self)
None	add_start_cb (self, Callable cb, List[Any] args=None)
None	add_transition_cb (self, Callable cb, List[Any] args=None)
None	add_end_cb (self, Callable cb, List[Any] args=None)
None	validate (self, bool strict_mode=False)
str	execute (self, Blackboard blackboard)
None	cancel_state (self)
str	__str__ (self)
Public Member Functions inherited from yasmin.state.State
str	__call__ (self, Blackboard blackboard=None)
bool	is_canceled (self)
bool	is_running (self)
Set[str]	get_outcomes (self)

Protected Member Functions
None	_call_start_cbs (self, Blackboard blackboard, str start_state)
None	_call_transition_cbs (self, Blackboard blackboard, str from_state, str to_state, str outcome)
None	_call_end_cbs (self, Blackboard blackboard, str outcome)

Protected Attributes
dict	_states = {}
	A dictionary mapping state names to their corresponding state objects and transitions.
str	_start_state = None
	The name of the initial state of the state machine.
bool	_validated = False
	A flag indicating whether the state machine has been validated.
	_outcomes
Protected Attributes inherited from yasmin.state.State
Set	_outcomes = set()
	A set of valid outcomes for this state.
bool	_running = False
	A flag indicating whether the state is currently running.
bool	_canceled = False
	A flag indicating whether the state has been canceled.

Private Attributes
str	__current_state = None
	The name of the current state being executed.
Lock	__current_state_lock = Lock()
	A threading lock to manage access to the current state.
List[	__start_cbs
	A list of callbacks to call when the state machine starts.
List[	__transition_cbs
	A list of callbacks to call during state transitions.
List[	__end_cbs
	A list of callbacks to call when the state machine ends.

Detailed Description

Represents a state machine that can manage states and transitions
between them, including callbacks for different state events.

Attributes:
    _states (Dict[str, Dict[str, Any]]): A dictionary mapping state names to their corresponding state objects and transitions.
    _start_state (str): The name of the initial state of the state machine.
    __current_state (str): The name of the current state being executed.
    __current_state_lock (Lock): A threading lock to manage access to the current state.
    _validated (bool): A flag indicating whether the state machine has been validated.
    __start_cbs (List[Tuple[Callable[[Blackboard, str, List[Any]], None], List[Any]]]): A list of callbacks to call when the state machine starts.
    __transition_cbs (List[Tuple[Callable[[Blackboard, str, List[Any]], None], List[Any]]]): A list of callbacks to call during state transitions.
    __end_cbs (List[Tuple[Callable[[Blackboard, str, List[Any]], None], List[Any]]]): A list of callbacks to call when the state machine ends.

Constructor & Destructor Documentation

__init__()

None yasmin.state_machine.StateMachine.__init__	(		self,
		Set[str]	outcomes )

Initializes the StateMachine with a set of possible outcomes.

Parameters:
    outcomes (Set[str]): A set of possible outcomes for the state machine.

Reimplemented from yasmin.state.State.

Member Function Documentation

__str__()

str yasmin.state_machine.StateMachine.__str__

(

self

)

Returns a string representation of the state machine, listing all states and their types.

Returns:
    str: A string representation of the state machine.

Reimplemented from yasmin.state.State.

_call_end_cbs()

None yasmin.state_machine.StateMachine._call_end_cbs ( self, Blackboard blackboard, str outcome )

protected

Executes all end callbacks.

Parameters:
    blackboard (Blackboard): The blackboard instance used for sharing state.
    outcome (str): The outcome of the state machine execution.

Raises:
    Exception: If an error occurs while executing a callback.

_call_start_cbs()

None yasmin.state_machine.StateMachine._call_start_cbs ( self, Blackboard blackboard, str start_state )

protected

Executes all start callbacks.

Parameters:
    blackboard (Blackboard): The blackboard instance used for sharing state.
    start_state (str): The name of the state machine's starting state.

Raises:
    Exception: If an error occurs while executing a callback.

_call_transition_cbs()

None yasmin.state_machine.StateMachine._call_transition_cbs ( self, Blackboard blackboard, str from_state, str to_state, str outcome )

protected

Executes all transition callbacks.

Parameters:
    blackboard (Blackboard): The blackboard instance used for sharing state.
    from_state (str): The state the transition is coming from.
    to_state (str): The state the transition is going to.
    outcome (str): The outcome of the transition.

Raises:
    Exception: If an error occurs while executing a callback.

add_end_cb()

None yasmin.state_machine.StateMachine.add_end_cb	(		self,
		Callable	cb,
		List[Any]	args = None )

Adds a callback to be called when the state machine ends.

Parameters:
    cb (Callable): The callback function to execute.
    args (List[Any], optional): A list of arguments to pass to the callback. Defaults to None.

add_start_cb()

None yasmin.state_machine.StateMachine.add_start_cb	(		self,
		Callable	cb,
		List[Any]	args = None )

Adds a callback to be called when the state machine starts.

Parameters:
    cb (Callable): The callback function to execute.
    args (List[Any], optional): A list of arguments to pass to the callback. Defaults to None.

add_state()

None yasmin.state_machine.StateMachine.add_state	(		self,
		str	name,
		State	state,
		Dict[str, str]	transitions = None )

Adds a new state to the state machine.

Parameters:
    name (str): The name of the state to add.
    state (State): The State object to associate with the name.
    transitions (Dict[str, str], optional): A dictionary mapping source outcomes to target states. Defaults to None.

Raises:
    KeyError: If the state name is already registered or is an outcome.
    ValueError: If transitions contain empty keys or values.
    KeyError: If transitions reference unregistered outcomes.

add_transition_cb()

None yasmin.state_machine.StateMachine.add_transition_cb	(		self,
		Callable	cb,
		List[Any]	args = None )

Adds a callback to be called during state transitions.

Parameters:
    cb (Callable): The callback function to execute.
    args (List[Any], optional): A list of arguments to pass to the callback. Defaults to None.

cancel_state()

None yasmin.state_machine.StateMachine.cancel_state

(

self

)

Cancels the current state and any associated operations.

Overrides the cancel_state method from the parent State class.

Reimplemented from yasmin.state.State.

execute()

str yasmin.state_machine.StateMachine.execute	(		self,
		Blackboard	blackboard )

Executes the state machine starting from the initial state.

Parameters:
    blackboard (Blackboard): The blackboard instance used for sharing state.

Returns:
    str: The final outcome of the state machine execution.

Raises:
    RuntimeError: If the execution is canceled unexpectedly.
    KeyError: If an outcome does not belong to a state or the state machine.

Reimplemented from yasmin.state.State.

get_current_state()

str yasmin.state_machine.StateMachine.get_current_state

(

self

)

Retrieves the name of the current state being executed.

Returns:
    str: The name of the current state, or an empty string if none is set.

get_start_state()

str yasmin.state_machine.StateMachine.get_start_state

(

self

)

Retrieves the name of the current starting state.

Returns:
    str: The name of the starting state.

get_states()

Dict[str, Union[State, Dict[str, str]]] yasmin.state_machine.StateMachine.get_states

(

self

)

Retrieves all states in the state machine.

Returns:
    Dict[str, Union[State, Dict[str, str]]]: A dictionary of states and their transitions.

set_start_state()

None yasmin.state_machine.StateMachine.set_start_state	(		self,
		str	state_name )

Sets the initial state for the state machine.

Parameters:
    state_name (str): The name of the initial state to set.

Raises:
    ValueError: If the state name is empty.
    KeyError: If the state name is not found in the states.

validate()

None yasmin.state_machine.StateMachine.validate	(		self,
		bool	strict_mode = False )

Validates the state machine to ensure all states and transitions are correct.

Parameters:
    strict_mode (bool): Whether the validation is strict, which means checking if all state outcomes are used and all state machine outcomes are reached.

Raises:
    RuntimeError: If no initial state is set.
    KeyError: If there are any unregistered outcomes or transitions.

Member Data Documentation

__current_state

str yasmin.state_machine.StateMachine.__current_state = None

private

The name of the current state being executed.

__current_state_lock

Lock yasmin.state_machine.StateMachine.__current_state_lock = Lock()

private

A threading lock to manage access to the current state.

__end_cbs

List[ yasmin.state_machine.StateMachine.__end_cbs

private

A list of callbacks to call when the state machine ends.

__start_cbs

List[ yasmin.state_machine.StateMachine.__start_cbs

private

A list of callbacks to call when the state machine starts.

__transition_cbs

List[ yasmin.state_machine.StateMachine.__transition_cbs

private

A list of callbacks to call during state transitions.

_outcomes

yasmin.state_machine.StateMachine._outcomes

protected

_start_state

str yasmin.state_machine.StateMachine._start_state = None

protected

The name of the initial state of the state machine.

_states

dict yasmin.state_machine.StateMachine._states = {}

protected

A dictionary mapping state names to their corresponding state objects and transitions.

_validated

bool yasmin.state_machine.StateMachine._validated = False

protected

A flag indicating whether the state machine has been validated.

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The documentation for this class was generated from the following file:

• yasmin/yasmin/state_machine.py