npm package: @stdlib/iter-cunone
Description: Create an iterator which cumulatively tests whether every iterated value is falsy.
Author: The Stdlib Authors
Latest version: 0.1.1

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# iterCuNone

[![NPM version][npm-image]][npm-url] [![Build Status][test-image]][test-url] [![Coverage Status][coverage-image]][coverage-url] <!-- [![dependencies][dependencies-image]][dependencies-url] -->

> Create an [iterator][mdn-iterator-protocol] which cumulatively tests whether every iterated value is falsy.

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<section class="intro">

</section>

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<!-- Package usage documentation. -->

<section class="installation">

## Installation

```bash
npm install @stdlib/iter-cunone
```

</section>

<section class="usage">

## Usage

```javascript
var iterCuNone = require( '@stdlib/iter-cunone' );
```

#### iterCuNone( iterator )

Returns an [iterator][mdn-iterator-protocol] which cumulatively tests whether every iterated value is falsy.

```javascript
var array2iterator = require( '@stdlib/array-to-iterator' );

var arr = array2iterator( [ 0, 0, 0, 1, 0 ] );

var it = iterCuNone( arr );
// returns <Object>

var v = it.next().value;
// returns true

v = it.next().value;
// returns true

v = it.next().value;
// returns true

v = it.next().value;
// returns false

v = it.next().value;
// returns false

var bool = it.next().done;
// returns true
```

The returned [iterator][mdn-iterator-protocol] protocol-compliant object has the following properties:

-   **next**: function which returns an [iterator][mdn-iterator-protocol] protocol-compliant object containing the next iterated value (if one exists) assigned to a `value` property and a `done` property having a `boolean` value indicating whether the [iterator][mdn-iterator-protocol] is finished.
-   **return**: function which closes an [iterator][mdn-iterator-protocol] and returns a single (optional) argument in an [iterator][mdn-iterator-protocol] protocol-compliant object.

</section>

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<!-- Package usage notes. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->

<section class="notes">

</section>

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<!-- Package usage examples. -->

<section class="examples">

## Examples

<!-- eslint no-undef: "error" -->

```javascript
var randu = require( '@stdlib/random-iter-randu' );
var iterMap = require( '@stdlib/iter-map' );
var iterCuNone = require( '@stdlib/iter-cunone' );

function threshold( r ) {
    return ( r > 0.95 );
}

// Create an iterator which generates uniformly distributed pseudorandom numbers:
var opts = {
    'iter': 100
};
var riter = randu( opts );

// Create an iterator which applies a threshold to generated numbers:
var miter = iterMap( riter, threshold );

// Create an iterator which cumulatively tests whether every iterated value is falsy:
var it = iterCuNone( miter );

// Perform manual iteration...
var r;
while ( true ) {
    r = it.next();
    if ( r.done ) {
        break;
    }
    console.log( r.value );
}
```

</section>

<!-- /.examples -->

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</section>

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<section class="related">

</section>

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<section class="main-repo" >

* * *

## Notice

This package is part of [stdlib][stdlib], a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.

For more information on the project, filing bug reports and feature requests, and guidance on how to develop [stdlib][stdlib], see the main project [repository][stdlib].

#### Community

[![Chat][chat-image]][chat-url]

---

## License

See [LICENSE][stdlib-license].


## Copyright

Copyright &copy; 2016-2026. The Stdlib [Authors][stdlib-authors].

</section>

<!-- /.stdlib -->

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<section class="links">

[npm-image]: http://img.shields.io/npm/v/@stdlib/iter-cunone.svg
[npm-url]: https://npmjs.org/package/@stdlib/iter-cunone

[test-image]: https://github.com/stdlib-js/iter-cunone/actions/workflows/test.yml/badge.svg?branch=v0.1.1
[test-url]: https://github.com/stdlib-js/iter-cunone/actions/workflows/test.yml?query=branch:v0.1.1

[coverage-image]: https://img.shields.io/codecov/c/github/stdlib-js/iter-cunone/main.svg
[coverage-url]: https://codecov.io/github/stdlib-js/iter-cunone?branch=main

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[stdlib]: https://github.com/stdlib-js/stdlib

[stdlib-authors]: https://github.com/stdlib-js/stdlib/graphs/contributors

[umd]: https://github.com/umdjs/umd
[es-module]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Modules

[deno-url]: https://github.com/stdlib-js/iter-cunone/tree/deno
[deno-readme]: https://github.com/stdlib-js/iter-cunone/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/iter-cunone/tree/umd
[umd-readme]: https://github.com/stdlib-js/iter-cunone/blob/umd/README.md
[esm-url]: https://github.com/stdlib-js/iter-cunone/tree/esm
[esm-readme]: https://github.com/stdlib-js/iter-cunone/blob/esm/README.md
[branches-url]: https://github.com/stdlib-js/iter-cunone/blob/main/branches.md

[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/iter-cunone/main/LICENSE

[mdn-iterator-protocol]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Iteration_protocols#The_iterator_protocol

</section>

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