import type * as RDF from '@rdfjs/types';
import type { PassThrough } from 'readable-stream';
/**
 * A PendingStreamsIndex stores pending streams indexed by the quad pattern they have been created for.
 */
export declare class PendingStreamsIndex<Q extends RDF.BaseQuad = RDF.Quad> {
    private static readonly ID_VARIABLE;
    private static readonly ID_SEPARATOR;
    readonly indexedStreams: Map<string, PassThrough[]>;
    readonly allStreams: PassThrough[];
    protected termToString(term?: RDF.Term | null): string;
    /**
     * Add a new pending stream for the given quad pattern.
     * @param pendingStream A pending stream.
     * @param subject A term.
     * @param predicate A term.
     * @param object A term.
     * @param graph A term.
     */
    addPatternListener(pendingStream: PassThrough, subject?: RDF.Term | null, predicate?: RDF.Term | null, object?: RDF.Term | null, graph?: RDF.Term | null): void;
    /**
     * Find all the pending streams from which their quad pattern match the given quad.
     * @param quad The quad to match patterns to.
     */
    getPendingStreamsForQuad(quad: Q): PassThrough[];
}