import { Future } from './future';
/**
 * @internal
 */
export type ProgressInspectionResult<Result, Progress> = {
    state: 'pending';
    progress: Progress;
} | {
    state: 'fulfilled';
    value: Result;
} | {
    state: 'rejected';
    reason: unknown;
};
/**
 * Create a promise, but with progress reporting
 *
 * @beta
 * @typeParam Result - type of the progress's fulfilled value
 * @typeParam CurrentProgress - type of current progress used in p.report or p.progress
 */
export declare class Progress<Result = unknown, CurrentProgress = unknown> extends Future<Result> {
    /**
     * creates a new progress object and runs the given function with the progress as parameter,
     * returns the created progress object.
     *
     * the function should report progress and call `progress.resolve` / `progress.reject` once done.
     *
     * @example
     * ```typescript
     * Progress.run((progress) => {
     *   progress.report(100)
     *   progress.resolve('hello')
     * }, 0)
     * ```
     */
    static run<Result = unknown, CurrentProgress = unknown>(fn: (progress: Progress<Result, CurrentProgress>) => unknown, initialProgress: CurrentProgress): Progress<Result, CurrentProgress>;
    private currentProgress;
    private listeners;
    /**
     * create a promise, but with progress reporting.
     */
    constructor(initialProgress: CurrentProgress);
    /**
     * get last reported progress (despite current progress state)
     */
    get progress(): CurrentProgress;
    /**
     * inspect the current progress, for debug purpose only.
     */
    inspect(): ProgressInspectionResult<Result, CurrentProgress>;
    /**
     * register a listener on progress report, and use the returned function to cancel listening.
     *
     * listeners won't receive messages on progress rejection
     */
    onProgress(listener: (progress: Readonly<CurrentProgress>) => unknown): () => boolean;
    /**
     * report current progress
     *
     * no-op if progress has already fulfilled or rejected
     */
    report(progress: CurrentProgress): void;
}
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