hierarchical_state_machine library

A hierarchical state machine (HSM) implementation for dart.

Classes

BasicBlueprint<S, E>

Base class for all state definitions in a MachineBlueprint.

ChoiceBlueprint<S, E>

A pseudostate that chooses a transition based on guards.

CompletionBlueprint<S, E>

Defines a completion transition (no event).

CompositeBlueprint<S, E>

A compound state that may contain children.

DefaultTransitionBlueprint<S, E>

Specialized transition for choice states (no guard).

DuplicateStateIdError<S>

Thrown when multiple states share the same ID.

FinalBlueprint<S, E>

A state representing a final node in a region.

ForkBlueprint<S, E>

A pseudostate that splits a transition into multiple simultaneous paths targeting different regions of a ParallelBlueprint.

ForkTransitionBlueprint<S, E>

Specialized transition for fork states.

ForkValidationError<S>

Thrown when a ForkState fails structural validation.

HsmState<S, E>

The read-only view of a state within a Machine.

InvalidInitialStateError<S>

Thrown when an initial state is not a proper descendant of its parent state.

InvalidRootError

Thrown when the root state is not a composite or parallel state.

Machine<S, E>

A hierarchical state machine (HSM) container of S states that accepts E events.

MachineBlueprint<S, E>

The root entry point for a state machine definition.

MachineObserver<S, E>

Observer interface for monitoring state machine execution.

MissingStateError<S>

Thrown when a transition or initial state targets a non-existent state.

ParallelBlueprint<S, E>

A compound state in which each direct child forms a region.

PrintObserver<S, E>

A default observer that prints machine activity to the console.

Serializer<S, E extends Object>

Serialize a hierarchial state machine for storage.

TerminateBlueprint<S, E>

A state representing a terminate node for the whole machine.

TransitionBlueprint<S, E>

Defines a transition to a target state.

UnknownDefinitionTypeError<S>

Thrown when an unknown definition type is encountered.

ValidationError

Base class for validation errors.

Enums

HistoryType

Defines the type of history restoration to apply during a transition.

StateType

The type of a state within a Machine.

TransitionKind

Defines whether a transition is local or external.

Extensions

StateTypeExtension on HsmState

Provides access to the StateType of an HsmState.

Typedefs

ActionFunction<E, D extends Object?> = void Function(E event, D data)

Function signature for transition effect behaviors.

GuardFunction<E, D extends Object?> = bool Function(E event, D data)

Function signature for guard conditions.

StateFunction = void Function()

Function signature for state entrance/exit behaviors.

Exceptions / Errors

FingerprintException

Thrown when fingerprints of serialized machines and new blueprints do not match.