Trait PersistenceModel 

pub trait PersistenceModel {
    type PState: Clone;
    type Delta: Clone;

    // Required methods
    fn apply(
        state: &mut Self::PState,
        delta: &Self::Delta,
    ) -> Result<(), String>;
    fn derive(
        before: &Self::PState,
        after: &Self::PState,
    ) -> Result<Self::Delta, String>;
    fn open_delta(session: SessionId) -> Self::Delta;
    fn close_delta(session: SessionId) -> Self::Delta;

    // Provided method
    fn invoke_delta(_session: SessionId, _action: &str) -> Option<Self::Delta> { ... }
}

Persistence-model contract.

Required Associated Types

type PState: Clone

Persistent state representation.

type Delta: Clone

Delta representation for incremental updates.

Required Methods

fn apply(state: &mut Self::PState, delta: &Self::Delta) -> Result<(), String>

Apply one delta to state.

Errors

Returns an error if the delta cannot be applied.

fn derive( before: &Self::PState, after: &Self::PState, ) -> Result<Self::Delta, String>

Derive a delta between two states.

Errors

Returns an error if derivation fails.

fn open_delta(session: SessionId) -> Self::Delta

Open-session lifecycle delta.

fn close_delta(session: SessionId) -> Self::Delta

Close-session lifecycle delta.

Provided Methods

fn invoke_delta(_session: SessionId, _action: &str) -> Option<Self::Delta>

Optional invoke-action delta.

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 PersistenceModel for NoopPersistence

type PState = ()

type Delta = ()