/*! ***************************************************************************** Copyright (c) Microsoft Corporation. All rights reserved. Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 THIS CODE IS PROVIDED ON AN *AS IS* BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION ANY IMPLIED WARRANTIES OR CONDITIONS OF TITLE, FITNESS FOR A PARTICULAR PURPOSE, MERCHANTABLITY OR NON-INFRINGEMENT. See the Apache Version 2.0 License for specific language governing permissions and limitations under the License. ***************************************************************************** */ /// <reference no-default-lib="true"/> type FlatArray<Arr, Depth extends number> = { done: Arr; recur: Arr extends ReadonlyArray<infer InnerArr> ? FlatArray<InnerArr, [-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20][Depth]> : Arr; }[Depth extends -1 ? "done" : "recur"]; interface ReadonlyArray<T> { /** * Calls a defined callback function on each element of an array. Then, flattens the result into * a new array. * This is identical to a map followed by flat with depth 1. * * @param callback A function that accepts up to three arguments. The flatMap method calls the * callback function one time for each element in the array. * @param thisArg An object to which the this keyword can refer in the callback function. If * thisArg is omitted, undefined is used as the this value. */ flatMap<U, This = undefined>( callback: (this: This, value: T, index: number, array: T[]) => U | ReadonlyArray<U>, thisArg?: This, ): U[]; /** * Returns a new array with all sub-array elements concatenated into it recursively up to the * specified depth. * * @param depth The maximum recursion depth */ flat<A, D extends number = 1>( this: A, depth?: D, ): FlatArray<A, D>[]; } interface Array<T> { /** * Calls a defined callback function on each element of an array. Then, flattens the result into * a new array. * This is identical to a map followed by flat with depth 1. * * @param callback A function that accepts up to three arguments. The flatMap method calls the * callback function one time for each element in the array. * @param thisArg An object to which the this keyword can refer in the callback function. If * thisArg is omitted, undefined is used as the this value. */ flatMap<U, This = undefined>( callback: (this: This, value: T, index: number, array: T[]) => U | ReadonlyArray<U>, thisArg?: This, ): U[]; /** * Returns a new array with all sub-array elements concatenated into it recursively up to the * specified depth. * * @param depth The maximum recursion depth */ flat<A, D extends number = 1>( this: A, depth?: D, ): FlatArray<A, D>[]; }