OverlayScrollbars/src/core/utils/arrays.ts

import { isArrayLike } from 'core/utils/types';
import { PlainObject } from 'core/typings';


/**
 * Iterates through a array or object
 * @param arrayLikeOrObject The array or object through which shall be iterated.
 * @param callback The function which is responsible for the iteration. 
 * If the function returns true its treated like a "continue" statement.
 * If the function returns false its treated like a "break" statement.
 */
export function each<T>(array: Array<T> | ReadonlyArray<T>, callback: (value: T, indexOrKey: number, source: Array<T>) => boolean | void): Array<T> | ReadonlyArray<T>;
export function each<T>(array: Array<T> | ReadonlyArray<T> | null, callback: (value: T, indexOrKey: number, source: Array<T>) => boolean | void): Array<T> | ReadonlyArray<T> | null;
export function each<T>(arrayLikeObject: ArrayLike<T>, callback: (value: T, indexOrKey: number, source: ArrayLike<T>) => boolean | void): ArrayLike<T>;
export function each<T>(arrayLikeObject: ArrayLike<T> | null, callback: (value: T, indexOrKey: number, source: ArrayLike<T>) => boolean | void): ArrayLike<T> | null;
export function each(obj: PlainObject, callback: (value: any, indexOrKey: string, source: PlainObject) => boolean | void): PlainObject;
export function each(obj: PlainObject | null, callback: (value: any, indexOrKey: string, source: PlainObject) => boolean | void): PlainObject | null;
export function each<T>(source: ArrayLike<T> | PlainObject | null, callback: (value: T | any, indexOrKey: any, source: any) => boolean | void): Array<T> | ReadonlyArray<T> | ArrayLike<T> | PlainObject | null {
    let i: number | string = 0;

    if (isArrayLike(source)) {
        for (; i < source.length; i++) {
            if (callback(source[i], i, source) === false)
                break;
        }
    }
    else if (source) {
        for (i in source) {
            if (callback(source[i], i, source) === false)
                break;
        }
    }
    return source;
};

/**
 * Returns the index of the given inside the given array or -1 if the given item isn't part of the given array.
 * @param arr The array.
 * @param item The item.
 * @param fromIndex The array index at which to begin the search. If fromIndex is omitted, the search starts at index 0.
 */
export const indexOf: <T = any>(arr: Array<T>, item: T, fromIndex?: number) => number = (arr, item, fromIndex) => {
    return arr.indexOf(item, fromIndex);
}