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feat: add iter/cuevery-by package
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PR-URL: #2838
Closes: #2336

Co-authored-by: Kaif Mohd <[email protected]>
Co-authored-by: Philipp Burckhardt <[email protected]>
Reviewed-by: Philipp Burckhardt <[email protected]>
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Kaif987 and Planeshifter authored Oct 9, 2024
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202 changes: 202 additions & 0 deletions lib/node_modules/@stdlib/iter/cuevery-by/README.md
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<!--
@license Apache-2.0
Copyright (c) 2024 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.
-->

# iterCuEveryBy

> Create an iterator which cumulatively tests whether every iterated value passes a test implemented by a predicate function.
<!-- Section to include introductory text. Make sure to keep an empty line after the intro `section` element and another before the `/section` close. -->

<section class="intro">

</section>

<!-- /.intro -->

<!-- Package usage documentation. -->

<section class="usage">

## Usage

```javascript
var iterCuEveryBy = require( '@stdlib/iter/cuevery-by' );
```

#### iterCuEveryBy( iterator, predicate\[, thisArg] )

Returns an [iterator][mdn-iterator-protocol] which cumulatively tests whether every iterated value passes a test implemented by a `predicate` function.

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

function predicate( v ) {
return ( v > 0 );
}

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

var it = iterCuEveryBy( arr, predicate );

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.

A `predicate` function is provided two arguments:

- **value**: iterated value
- **index**: iteration index (zero-based)

To set the `predicate` function execution context, provide a `thisArg`.

<!-- eslint-disable no-invalid-this -->

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

function predicate( v ) {
this.count += 1;
return ( v > 0 );
}

var ctx = {
'count': 0
};

var it = iterCuEveryBy( array2iterator( [ 1, 2, 3, 4 ] ), predicate, ctx );
// 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 true

var count = ctx.count;
// returns 4
```

</section>

<!-- /.usage -->

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

<section class="notes">

## Notes

- A `predicate` function is invoked for each iterated value until the first falsy `predicate` function return value. Upon encountering the first falsy return value, the returned iterator ceases to invoke the `predicate` function and returns `false` for each subsequent iterated value of the provided input `iterator`.

</section>

<!-- /.notes -->

<!-- Package usage examples. -->

<section class="examples">

## Examples

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

```javascript
var randu = require( '@stdlib/random/iter/randu' );
var iterCuEveryBy = require( '@stdlib/iter/cuevery-by' );

function threshold( r ) {
return ( r > 0.05 );
}

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

// Create an iterator which cumulatively tests whether every iterated value passes a test:
var it = iterCuEveryBy( riter, threshold );

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

</section>

<!-- /.examples -->

<!-- Section to include cited references. If references are included, add a horizontal rule *before* the section. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->

<section class="references">

</section>

<!-- /.references -->

<!-- Section for related `stdlib` packages. Do not manually edit this section, as it is automatically populated. -->

<section class="related">

</section>

<!-- /.related -->

<!-- Section for all links. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->

<section class="links">

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

</section>

<!-- /.links -->
89 changes: 89 additions & 0 deletions lib/node_modules/@stdlib/iter/cuevery-by/benchmark/benchmark.js
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/**
* @license Apache-2.0
*
* Copyright (c) 2024 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.
*/

'use strict';

// MODULES //

var bench = require( '@stdlib/bench' );
var iterConstant = require( '@stdlib/iter/constant' );
var isIteratorLike = require( '@stdlib/assert/is-iterator-like' );
var isBoolean = require( '@stdlib/assert/is-boolean' ).isPrimitive;
var pkg = require( './../package.json' ).name;
var iterCuEveryBy = require( './../lib' );


// FUNCTIONS //

/**
* Predicate function.
*
* @private
* @param {*} value - value
* @returns {boolean} result
*/
function predicate( value ) {
return ( value > 0 );
}


// MAIN //

bench( pkg, function benchmark( b ) {
var iter;
var it;
var i;

it = iterConstant( 3.14 );

b.tic();
for ( i = 0; i < b.iterations; i++ ) {
iter = iterCuEveryBy( it, predicate );
if ( typeof iter !== 'object' ) {
b.fail( 'should return an object' );
}
}
b.toc();
if ( !isIteratorLike( iter ) ) {
b.fail( 'should return an iterator protocol-compliant object' );
}
b.pass( 'benchmark finished' );
b.end();
});

bench( pkg+'::iteration', function benchmark( b ) {
var iter;
var v;
var i;

iter = iterCuEveryBy( iterConstant( 3.14 ), predicate );

b.tic();
for ( i = 0; i < b.iterations; i++ ) {
v = iter.next().value;
if ( !isBoolean( v ) ) {
b.fail( 'should return a boolean' );
}
}
b.toc();
if ( !isBoolean( v ) ) {
b.fail( 'should return a boolean' );
}
b.pass( 'benchmark finished' );
b.end();
});
64 changes: 64 additions & 0 deletions lib/node_modules/@stdlib/iter/cuevery-by/docs/repl.txt
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{{alias}}( iterator, predicate[, thisArg] )
Returns an iterator which cumulatively tests whether every iterated value
passes a test implemented by a predicate function.

If an environment supports Symbol.iterator and a provided iterator is
iterable, the returned iterator is iterable.

The predicate function is provided two arguments:

- value: iterated value
- index: iteration index

A predicate function is invoked for each iterated value until the first
falsy predicate function return value. Upon encountering the first falsy
return value, the returned iterator ceases to invoke the predicate function
and returns `false` for each subsequent iterated value of the provided input
iterator.

If provided an iterator which does not return any iterated values, the
function returns an iterator which is also empty.

Parameters
----------
iterator: Object
Input iterator.

predicate: Function
The test function.

thisArg: any (optional)
Execution context.

Returns
-------
iterator: Object
Iterator.

iterator.next(): Function
Returns an iterator protocol-compliant object containing the next
iterated value (if one exists) and a boolean flag indicating whether the
iterator is finished.

iterator.return( [value] ): Function
Finishes an iterator and returns a provided value.

Examples
--------
> var arr = {{alias:@stdlib/array/to-iterator}}( [ 1, 1, 1, 0, 1 ] );
> function fcn( v ) { return ( v > 0 ); };
> var it = {{alias}}( arr, fcn );
> var v = it.next().value
true
> v = it.next().value
true
> v = it.next().value
true
> v = it.next().value
false
> v = it.next().value
false

See Also
--------
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Coverage Report

Package Statements Branches Functions Lines
iter/cuevery-by $\color{green}223/223$
$\color{green}+100.00\%$
$\color{green}21/21$
$\color{green}+100.00\%$
$\color{green}4/4$
$\color{green}+100.00\%$
$\color{green}223/223$
$\color{green}+100.00\%$

The above coverage report was generated for the changes in this push.

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