import type * as RDF from '@rdfjs/types';
/**
 * A query engine handler.
 */
export interface IQueryEngine {
    parse: (queryString: string, options: Record<string, any>) => Promise<void>;
    query: (data: RDF.Quad[], queryString: string, options: Record<string, any>) => Promise<IQueryResult>;
    queryResultFormat?: (data: RDF.Quad[], queryString: string, mediaType: string, options: Record<string, any>) => Promise<NodeJS.ReadableStream>;
}
/**
 * Super type for all query result types.
 */
export type IQueryResult = IQueryResultBoolean | IQueryResultQuads | IQueryResultBindings;
/**
 * Holds a boolean query result.
 */
export interface IQueryResultBoolean {
    type: 'boolean';
    value: boolean;
    equals: (that: IQueryResult, laxCardinality?: boolean) => boolean;
    toString: () => string;
}
/**
 * Holds quad-based query results.
 */
export interface IQueryResultQuads {
    type: 'quads';
    value: RDF.Quad[];
    equals: (that: IQueryResult, laxCardinality?: boolean) => boolean;
    toString: () => string;
}
/**
 * Holds bindings-based query results.
 */
export interface IQueryResultBindings {
    type: 'bindings';
    variables: string[];
    value: Record<string, RDF.Term>[];
    checkOrder: boolean;
    equals: (that: IQueryResult, laxCardinality?: boolean) => boolean;
    toString: () => string;
}