import { Selector, Predicate } from '../types';
/**
 * Groups array items based on elementSelector function
 * @param array The array to process.
 * @param elementSelector Function invoked per iteration.
 */
export declare function groupBy(array: any[], groupByFields: string | string[] | Selector): any[];
/**
 * Returns a distinct elements from array.
 * Optional parameter *elementSelector* will create new array based on a callback function,
 * then will eliminate dublicates
 * @param array
 * @param elementSelector
 * @returns
 */
export declare function distinct(array: any[], elementSelector?: Selector): any[];
/**
 * Flatten Object or array of objects
 * Object
 * [{ a: 1, d:{d1: 22, d2: 33} }, { b: 2, d:{d1:221, d2:331} }]
 * will become
 * [{ a: 1, d.d1: 22, d.d2: 33 }, { b: 2, d.d1: 221, d.d2: 331 }]
 * @param data
 * @returns
 */
export declare function unflattenObject(data: any): any;
export declare function flattenObject(data: any): any;
/**
 * Flattens array.
 * @param array The array to flatten recursively.
 * @example
 * flatten([1, 4, [2, [5, 5, [9, 7]], 11], 0]); // length 9
 */
export declare function flatten(array: any[]): any[];
/**
 * Returns a reshaped array based on unique column values.
 * @param array array to pivot
 * @param rowFields row fields (or index fields). It can be one or more field names
 * @param columnField a field which values will be used to create columns
 * @param dataField a dataField which will be aggrated with aggregate function and groupped by rows and columns
 * @param aggFunction an aggregation function. Default value is sum. data field will be aggregated by this function
 * @param columnValues an optional initial column values. Use it to define a set of columns/values you would expect
 */
export declare function pivot(array: any, rowFields: string | string[], columnField: string, dataField: string, aggFunction?: (array: any[]) => any | null, columnValues?: string[]): any[];
/**
 * Transpose rows to columns in an array
 * @param data
 */
export declare function transpose(data: any[]): any[];
/**
 * Creates new array based on selector.
 * @param array The array to process.
 * @param elementSelector Function invoked per iteration.
 */
export declare function select(data: any[], selector: string | string[] | Selector): any[];
/**
 * Filters array based on predicate function.
 * @param array The array to process.
 * @param elementSelector Function invoked per iteration.
 */
export declare function where(data: any[], predicate: Predicate): any[];
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