Struct StateMachine 

pub struct StateMachine {
    pub states: Vec<WorkflowState>,
    pub transitions: Vec<WorkflowTransition>,
    pub current_state: String,
}

A finite state machine composed of WorkflowStates and WorkflowTransitions.

Fields

states: Vec<WorkflowState>

All registered states.

transitions: Vec<WorkflowTransition>

All registered transitions.

current_state: String

ID of the currently active state.

Implementations

impl StateMachine

pub fn new(initial_state_id: impl Into<String>) -> Self

Create a new FSM with initial_state_id as the starting state.

The initial state is NOT required to exist in states at construction time; it is added implicitly when the first state is added.

pub fn add_state(&mut self, state: WorkflowState)

Register a state.

pub fn add_transition(&mut self, t: WorkflowTransition)

Register a transition.

pub fn trigger(&mut self, event: &str) -> bool

Fire event. Returns true if a transition was found and applied.

A transition is eligible when:

1. Its from field matches current_state.
2. Its trigger matches event.
3. The current state is not terminal.

pub fn current(&self) -> &str

Return the ID of the current state.

pub fn is_terminal(&self) -> bool

Returns true when the current state is marked terminal.

pub fn valid_triggers(&self) -> Vec<&str>

Return the event names of all transitions originating from the current state.

Trait Implementations

impl Clone for StateMachine

fn clone(&self) -> StateMachine

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for StateMachine

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.