@stdlib/iter
Version:
Standard iterator utilities.
62 lines (53 loc) • 1.7 kB
TypeScript
/*
* @license Apache-2.0
*
* Copyright (c) 2019 The Stdlib Authors.
*
* 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
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
// TypeScript Version: 4.1
/// <reference types="@stdlib/types"/>
import { Iterator as Iter, IterableIterator } from '@stdlib/types/iter';
// Define a union type representing both iterable and non-iterable iterators:
type Iterator = Iter | IterableIterator;
/**
* Returns an iterator which returns the first `n` values of a provided iterator.
*
* ## Notes
*
* - If a provided iterator only generates `m` values and `m` is less than `n`, the returned iterator only returns `m` values.
* - If an environment supports `Symbol.iterator` **and** a provided iterator is iterable, the returned iterator is iterable.
*
* @param iterator - input iterator
* @param n - number of values
* @returns iterator
*
* @example
* var randu = require( '@stdlib/random/iter/randu' );
*
* var iter = iterHead( randu(), 10 );
*
* var r = iter.next().value;
* // returns <number>
*
* r = iter.next().value;
* // returns <number>
*
* r = iter.next().value;
* // returns <number>
*
* // ...
*/
declare function iterHead( iterator: Iterator, n: number ): Iterator;
// EXPORTS //
export = iterHead;