import { Cluster } from "couchbase";
import { Document } from "@langchain/core/documents";
import { BaseDocumentLoader, DocumentLoader } from "@langchain/core/document_loaders/base";
/**
 * loader for couchbase document
 */
export declare class CouchbaseDocumentLoader extends BaseDocumentLoader implements DocumentLoader {
    private cluster;
    private query;
    private pageContentFields?;
    private metadataFields?;
    /**
     * construct Couchbase document loader with a requirement for couchbase cluster client
     * @param client { Cluster } [ couchbase connected client to connect to database ]
     * @param query { string } [ query to get results from while loading the data ]
     * @param pageContentFields { Array<string> } [ filters fields of the document and shows these only ]
     * @param metadataFields { Array<string> } [ metadata fields required ]
     */
    constructor(client: Cluster, query: string, pageContentFields?: string[], metadataFields?: string[]);
    /**
     * Function to load document based on query from couchbase
     * @returns {Promise<Document[]>} [ Returns a promise of all the documents as array ]
     */
    load(): Promise<Document[]>;
    /**
     * Function to load documents based on iterator rather than full load
     * @returns {AsyncIterable<Document>} [ Returns an iterator to fetch documents ]
     */
    lazyLoad(): AsyncIterable<Document>;
}