Trait StateMachineBehavior 

pub trait StateMachineBehavior: Sized {
    type State: Copy + PartialEq + Default + Display;
    type Transition: TransitionMeta<Self::State>;

    // Required methods
    fn current_state(&self) -> Self::State;
    fn set_current_state(&mut self, state: Self::State);
    fn can_transition(&self, transition: Self::Transition) -> bool;

    // Provided methods
    fn new() -> Self
       where Self: Default { ... }
    fn from_state(state: Self::State) -> Self
       where Self: Default { ... }
    fn can_transition_with_role(
        &self,
        transition: Self::Transition,
        role: &str,
    ) -> bool { ... }
    fn transition(
        &mut self,
        transition: Self::Transition,
    ) -> Result<Self::State, StateMachineError> { ... }
    fn transition_with_role(
        &mut self,
        transition: Self::Transition,
        role: &str,
    ) -> Result<Self::State, StateMachineError> { ... }
    fn available_transitions(&self) -> Vec<Self::Transition> { ... }
    fn available_transitions_for_role(
        &self,
        role: &str,
    ) -> Vec<Self::Transition> { ... }
    fn transition_to_state(
        &mut self,
        target: Self::State,
    ) -> Result<Self::State, StateMachineError> { ... }
}

Trait that provides all mechanical state machine methods as default impls.

Implementors only need to define three methods:

• current_state() — read the current state field
• set_current_state() — write the current state field
• can_transition() — the unique per-entity transition table

All other methods (transition, transition_with_role, available_transitions, available_transitions_for_role, transition_to_state, can_transition_with_role) are provided for free.

Required Associated Types

type State: Copy + PartialEq + Default + Display

type Transition: TransitionMeta<Self::State>

Required Methods

fn current_state(&self) -> Self::State

fn set_current_state(&mut self, state: Self::State)

fn can_transition(&self, transition: Self::Transition) -> bool

The unique per-entity transition table.

Provided Methods

fn new() -> Self

where Self: Default,

fn from_state(state: Self::State) -> Self

where Self: Default,

fn can_transition_with_role( &self, transition: Self::Transition, role: &str, ) -> bool

Check if a transition is allowed for the given role.

fn transition( &mut self, transition: Self::Transition, ) -> Result<Self::State, StateMachineError>

Apply a transition, returning the new state on success.

fn transition_with_role( &mut self, transition: Self::Transition, role: &str, ) -> Result<Self::State, StateMachineError>

Apply a transition with role authorization check.

fn available_transitions(&self) -> Vec<Self::Transition>

All transitions valid from the current state.

fn available_transitions_for_role(&self, role: &str) -> Vec<Self::Transition>

All transitions valid from the current state for the given role.

fn transition_to_state( &mut self, target: Self::State, ) -> Result<Self::State, StateMachineError>

Transition directly to a target state by finding any valid transition that leads there from the current state.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors