/**
 * [WHO]: EventStream, AssistantMessageEventStream, createAssistantMessageEventStream
 * [FROM]: Depends on ai message/event types and event-stream-types structural contract
 * [TO]: Consumed by core/lib/ai/src/index.ts
 * [HERE]: core/lib/ai/src/utils/event-stream.ts - async event queue with final-result tracking
 */
import type { AssistantMessage, AssistantMessageEvent } from "../types.js";
import type { AsyncEventStream } from "./event-stream-types.js";
export declare class EventStream<T, R = T> implements AsyncEventStream<T, R> {
    private isComplete;
    private extractResult;
    private queue;
    private waiting;
    private done;
    private finalResult?;
    private hasFinalResult;
    private finalResultPromise;
    private resolveFinalResult;
    constructor(isComplete: (event: T) => boolean, extractResult: (event: T) => R);
    push(event: T): void;
    end(result?: R): void;
    [Symbol.asyncIterator](): AsyncIterator<T>;
    result(): Promise<R>;
    resultIfResolved(): R | undefined;
    private setFinalResult;
}
export declare class AssistantMessageEventStream extends EventStream<AssistantMessageEvent, AssistantMessage> {
    constructor();
}
/** Factory function for AssistantMessageEventStream (for use in extensions) */
export declare function createAssistantMessageEventStream(): AssistantMessageEventStream;