About

Hierarchical state machine library with support for SCXML and Graphviz visualization:

EventName = str
"""Event name"""

StateName = str
"""State name"""

ActionName = str
"""Action name"""

ConditionName = str
"""Condition name"""

class Event(typing.NamedTuple):
    name: EventName
    payload: typing.Any = None

class Transition(typing.NamedTuple):
    event: EventName
    target: typing.Optional[StateName]
    actions: typing.List[ActionName] = []
    conditions: typing.List[ConditionName] = []
    internal: bool = False

class State(typing.NamedTuple):
    name: StateName
    children: typing.List['State'] = []
    transitions: typing.List[Transition] = []
    entries: typing.List[ActionName] = []
    exits: typing.List[ActionName] = []
    final: bool = False

Action = typing.Callable[[typing.Optional[Event]], None]
"""Action function"""

Condition = typing.Callable[[typing.Optional[Event]], bool]
"""Condition function"""

class Statechart:
    """Statechart engine"""

    def __init__(self,
                 states: typing.Iterable[State],
                 actions: typing.Dict[str, Action],
                 conditions: typing.Dict[str, Condition] = {}): ...

    @property
    def state(self) -> typing.Optional[StateName]:
        """Current state"""

    def register(self, event: Event):
        """Add event to queue"""

    async def run(self):
        """Run statechart"""

def parse_scxml(scxml: typing.Union[typing.TextIO, pathlib.Path]
                ) -> typing.List[State]:
    """Parse SCXML"""


def create_dot_graph(states: typing.Iterable[State]) -> str:
    """Create DOT representation of statechart"""