import { Properties, Property, SystemProperty } from "./WidgetXml";
export declare function extractProperties(props: Properties): Property[];
export declare function extractSystemProperties(props: Properties): SystemProperty[];
export declare function capitalizeFirstLetter(text: string): string;
export declare function commasAnd(arr: string[]): string;
/**
 * Factory method for creating an `Array.reduce()` callback for partitioning the array into groups.
 * @example
 * ```js
 * [1, 4, 3, 13].reduce(groupBy(x => x % 2 ? "odd" : "even")).even // [ 4 ]
 * ```
 * @param groupSelector Callback that maps array members to their group
 * @returns Callback for Array.reduce()
 */
export declare function groupBy<T, Groups extends string>(groupSelector: (item: T) => Groups): (reduction: { [Group in Groups]?: T[]; }, item: T) => { [Group in Groups]?: T[]; };