Trait DemoEngine 

pub trait DemoEngine: Sized + Clone {
    type Config: DeserializeOwned + Debug;
    type State: Clone + Serialize + DeserializeOwned + PartialEq + Debug;
    type StepResult: Debug;

    // Required methods
    fn from_yaml(yaml: &str) -> Result<Self, DemoError>;
    fn from_config(config: Self::Config) -> Self;
    fn config(&self) -> &Self::Config;
    fn reset(&mut self);
    fn reset_with_seed(&mut self, seed: u64);
    fn step(&mut self) -> Self::StepResult;
    fn is_complete(&self) -> bool;
    fn state(&self) -> Self::State;
    fn restore(&mut self, state: &Self::State);
    fn step_count(&self) -> u64;
    fn seed(&self) -> u64;
    fn meta(&self) -> &DemoMeta;
    fn falsification_criteria(&self) -> Vec<FalsificationCriterion>;
    fn evaluate_criteria(&self) -> Vec<CriterionResult>;
    fn metamorphic_relations(&self) -> Vec<MetamorphicRelation>;
    fn verify_mr(&self, mr: &MetamorphicRelation) -> MrResult;

    // Provided methods
    fn run(&mut self, n: usize) -> Vec<Self::StepResult> { ... }
    fn is_verified(&self) -> bool { ... }
    fn verify_all_mrs(&self) -> Vec<MrResult> { ... }
}

MANDATORY trait for ALL demos (EDD-compliant).

Per specification SIMULAR-DEMO-001, all demos must implement this trait to ensure:

• YAML-first configuration
• Deterministic replay
• Renderer independence
• Falsification support
• Metamorphic testing

Example

impl DemoEngine for TspEngine {
    type Config = TspConfig;
    type State = TspState;
    type StepResult = TspStepResult;

    fn from_yaml(yaml: &str) -> Result<Self, DemoError> {
        let config: TspConfig = serde_yaml::from_str(yaml)?;
        Ok(Self::from_config(config))
    }
    // ... other methods
}

Required Associated Types

type Config: DeserializeOwned + Debug

Configuration type loaded from YAML.

type State: Clone + Serialize + DeserializeOwned + PartialEq + Debug

State snapshot for replay/audit.

type StepResult: Debug

Result of a single step.

Required Methods

fn from_yaml(yaml: &str) -> Result<Self, DemoError>

Create engine from YAML configuration string.

Errors

Returns DemoError::YamlParse if YAML is invalid. Returns DemoError::Validation if config fails validation.

fn from_config(config: Self::Config) -> Self

Create engine from config struct.

fn config(&self) -> &Self::Config

Get the current configuration.

fn reset(&mut self)

Reset to initial state (same seed = same result).

fn reset_with_seed(&mut self, seed: u64)

Reset with a new seed.

fn step(&mut self) -> Self::StepResult

Execute one step (deterministic given state + seed).

fn is_complete(&self) -> bool

Check if simulation is complete/converged.

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

Get current state snapshot (for replay verification).

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

Restore from a state snapshot.

fn step_count(&self) -> u64

Get current step number.

fn seed(&self) -> u64

Get seed for reproducibility.

fn meta(&self) -> &DemoMeta

Get demo metadata.

fn falsification_criteria(&self) -> Vec<FalsificationCriterion>

Get falsification criteria from config.

fn evaluate_criteria(&self) -> Vec<CriterionResult>

Evaluate all criteria against current state.

fn metamorphic_relations(&self) -> Vec<MetamorphicRelation>

Get metamorphic relations for this demo.

fn verify_mr(&self, mr: &MetamorphicRelation) -> MrResult

Verify a specific metamorphic relation.

Provided Methods

fn run(&mut self, n: usize) -> Vec<Self::StepResult>

Execute N steps.

fn is_verified(&self) -> bool

Check if all criteria pass.

fn verify_all_mrs(&self) -> Vec<MrResult>

Verify all metamorphic relations.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors

impl DemoEngine for OrbitalEngine

type Config = OrbitConfig

type State = OrbitalState

type StepResult = OrbitalStepResult

impl DemoEngine for TspEngine

type Config = TspConfig

type State = TspState

type StepResult = TspStepResult