import { AnyParamConstructor } from '@typegoose/typegoose/lib/types';
import { PipelineStage } from 'mongoose';
import { ExoAggrSuper } from '../../ExoAggrSuper';
type MetaKey = 'searchScore' | 'searchScoreDetails' | 'searchHighlights' | 'textScore' | 'indexKey' | 'searchKeywords';
export declare class ASProjection<T extends AnyParamConstructor<any>> {
    $aggr: ExoAggrSuper<T>;
    private $rules;
    private $metas;
    private $prefields;
    private fields;
    constructor($aggr: ExoAggrSuper<T>, $prefield: string | null);
    protected setupBaseFields(basefields: string[]): void;
    inclusion(...keys: string[]): this;
    exclusion(...keys: string[]): this;
    meta($meta: MetaKey, path: string): this;
    private setRule;
    private parseKeys;
    private parseSubFields;
    private pushSubFields;
    protected get project(): PipelineStage | void;
    protected cloneProjection(stage: ASProjection<T>): void;
}
export {};