Optimistic · API reference

Import

import { Optimistic } from "@typed/async-data";

export interface Optimistic<A, E> {
    readonly _tag: "Optimistic";
    readonly value: A;
    readonly previous: AsyncData<A, E>;
}

Preserving history makes rollback and nested optimistic transformations explicit rather than hiding them in renderer state.

This plain wrapper acquires no resources and retains its previous state; readonly is compile-time only.

The discriminant for optimistic state.

The literal tag enables explicit optimistic handling and cycle-safe traversal.

Inherits the resource-free lifetime of its enclosing state.

The state to restore or inspect beneath this optimistic layer.

Explicit history supports deterministic rollback and transformation of nested optimistic states.

Inherits the enclosing optimistic wrapper’s resource-free lifetime.

The value currently presented optimistically.

Separating the provisional value from history makes pending intent directly observable.

Inherits the enclosing state’s lifetime; the caller retains ownership of the referenced value.

import { optimistic, success } from "@typed/async-data"
const state = optimistic(success(1), 2)