import { BooleanOperator } from '../boolean-operator';
/**
 * Abstraction of queries, so that their implementation can be replaced as needed.
 */
export declare class Query {
    private _value;
    private _empty;
    /**
     * @param _value see [value]{@link Query#value} for the specification of this attribute.
     * @param _empty use `true` if the Query object represents an empty query
     */
    constructor(_value: string, _empty?: boolean);
    /**
     * @returns an Elastic search Query string query wrapped in braces.
     *
     * See Elasticsearch's
     * [documentation]{@link https://www.elastic.co/guide/en/elasticsearch/reference/current/query-dsl-query-string-query.html}
     * for more information about Query string queries.
     */
    get value(): string;
    /**
     * @returns whether this Query object represents an empty query or not
     */
    get isEmpty(): boolean;
    /**
     * Combines multiple queries into one with the provided operator.
     * @param queries queries that should be combined. Empty queries in the input array are ignored.
     * @param operator operator that is used to combine the queries
     * @returns a single query that is the combination of the non-empty queries in the input array. If the input array is empty an
     * [empty query]{@link Query#emptyQuery} will be returned.
     */
    static combineQueries(queries: Array<Query>, operator: BooleanOperator): Query;
    /**
     * Returns a `Query` with it's `value` set to an empty string.
     */
    static emptyQuery(): Query;
    /**
     * @param query the query that should be compared
     * @returns `true` if and only if the queries are equal.
     * Returns `false` if the queries are not equal, or if attempting to tell the queries apart is too complicated.
     * More specifically the method can always tell apart empty queries and if poth queries are non-empty then their values are compared.
     */
    equals(query: Query): boolean;
}