import { kState, kType } from './util.js';
import type { ReadableStream } from './readable-stream.js';
import type { WritableStream } from './writable-stream.js';
type PromiseAlgorithm = (...args: unknown[]) => Promise<unknown>;
interface StreamTransformer extends Transformer {
    cancel?: (reason?: unknown) => unknown;
}
interface BackpressureChange {
    promise: Promise<void> | undefined;
    resolve: ((value: void | PromiseLike<void>) => void) | undefined;
    reject: ((reason?: unknown) => void) | undefined;
}
interface TransformStreamState {
    readable: ReadableStream;
    writable: WritableStream;
    controller: TransformStreamDefaultController | undefined;
    backpressure: boolean | undefined;
    backpressureChange: BackpressureChange;
}
interface TransformControllerState {
    stream: TransformStream;
    transformAlgorithm: PromiseAlgorithm | undefined;
    flushAlgorithm: PromiseAlgorithm | undefined;
    cancelAlgorithm: PromiseAlgorithm | undefined;
    finishPromise: Promise<void> | undefined;
}
export declare class TransformStream {
    [kType]: string;
    [kState]: TransformStreamState;
    constructor(transformer?: StreamTransformer | null, writableStrategy?: QueuingStrategy, readableStrategy?: QueuingStrategy);
    get readable(): any;
    get writable(): any;
    get [Symbol.toStringTag](): string;
}
export declare class TransformStreamDefaultController {
    [kType]: string;
    [kState]: TransformControllerState;
    constructor(skipThrowSymbol?: symbol);
    get desiredSize(): number | null;
    enqueue(chunk?: unknown): void;
    error(reason?: unknown): void;
    terminate(): void;
    get [Symbol.toStringTag](): string;
}
export declare const isTransformStream: (value: unknown) => value is TransformStream;
export declare const isTransformStreamDefaultController: (value: unknown) => value is TransformStreamDefaultController;
export {};