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".

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