import { Any, AnyObject, Options } from "../../types";
export declare function filterDocumentsStage(pipeline: AnyObject[] | undefined, options: Options): {
    documents?: AnyObject[];
    pipeline?: AnyObject[];
};
interface ProjectMetadata {
    exclusions: string[];
    inclusions: string[];
    positional: number;
}
export declare function validateProjection(expr: AnyObject, options: Options, isRoot?: boolean): ProjectMetadata;
export declare function resolveCollection(op: string, expr: Any, options: Options): AnyObject[];
export {};