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150 changes: 150 additions & 0 deletions lib/node_modules/@stdlib/string/base/for-each-right/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.

-->

# forEachRight

> Invokes a function for each UTF-16 code unit in a string iterating from right to left.

<!-- 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 forEachRight = require( '@stdlib/string/base/for-each-right' );
```

#### forEachRight( str, clbk\[, thisArg ] )

Invokes a function for each UTF-16 code unit in a string iterating from right to left.

```javascript
function log( value, index ) {
console.log( '%d: %s', index, value );
}

forEachRight( 'Beep!', log );
/* =>
4: !
3: p
2: e
1: e
0: B
*/
```

The invoked function is provided three arguments:

- **value**: character.
- **index**: character index.
- **str**: input string.

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

```javascript
function clbk() {
this.count += 1;
}

var str = '👉🏿';

var ctx = {
'count': 0
};

forEachRight( str, clbk, ctx );

var cnt = 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">

</section>

<!-- /.notes -->

<!-- Package usage examples. -->

<section class="examples">

## Examples

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

```javascript
var forEachRight = require( '@stdlib/string/base/for-each-right' );

function log( value, index ) {
console.log( '%d: %s', index, value );
}

forEachRight( 'presidential election', log );
forEachRight( 'Iñtërnâtiônàlizætiøn', log );
forEachRight( '🌷🍕', log );
forEachRight( '\uD834\uDD1E', log );
```

</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">

<!-- <related-links> -->

<!-- </related-links> -->

</section>

<!-- /.links -->
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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 isString = require( '@stdlib/assert/is-string' ).isPrimitive;
var pkg = require( './../package.json' ).name;
var forEachRight = require( './../lib' );


// MAIN //

bench( pkg, function benchmark( b ) {
var values;
var out;
var i;

values = [
'Iñtërnâtiônàlizætiøn',
'presidential election',
'🐶🐮🐷🐰🐸'
];

b.tic();
for ( i = 0; i < b.iterations; i++ ) {
out = forEachRight( values[ i%values.length ], clbk );
if ( typeof out !== 'string' ) {
b.fail( 'should return a string' );
}
}
b.toc();
if ( !isString( out ) ) {
b.fail( 'should return a string' );
}
b.pass( 'benchmark finished' );
b.end();

function clbk( v ) {
if ( typeof v !== 'string' ) {
b.fail( 'unexpected value' );
}
}
});
38 changes: 38 additions & 0 deletions lib/node_modules/@stdlib/string/base/for-each-right/docs/repl.txt
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{{alias}}( str, clbk[, thisArg] )
Invokes a function for each UTF-16 code unit in a string, iterating from
right to left.

When invoked, the provided function is provided three arguments:

- value: character
- index: character index
- str: input string

Parameters
----------
str: string
Input string over which to iterate.

clbk: Function
Function to invoke for each UTF-16 code unit in the input string.

thisArg: any (optional)
Execution context.

Returns
-------
out: string
Input string.

Examples
--------
> var n = 0;
> function fcn() { n += 1; };
> {{alias}}( 'hello world!', fcn );
> n
12

See Also
--------

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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.
*/

// TypeScript Version: 4.1

/**
* Callback invoked for each UTF-16 code unit in a string.
*
* @returns result
*/
type Nullary = () => any;

/**
* Callback invoked for each UTF-16 code unit in a string.
*
* @param value - character
* @returns result
*/
type Unary = ( value: string ) => any;

/**
* Callback invoked for each UTF-16 code unit in a string.
*
* @param value - character
* @param index - character index
* @returns result
*/
type Binary = ( value: string, index: number ) => any;

/**
* Callback invoked for each UTF-16 code unit in a string.
*
* @param value - character
* @param index - character index
* @param str - input string
* @returns result
*/
type Ternary = ( value: string, index: number, str: string ) => any;

/**
* Callback invoked for each UTF-16 code unit in a string.
*
* @param value - character
* @param index - character index
* @param str - input string
* @returns result
*/
type Callback = Nullary | Unary | Binary | Ternary;

/**
* Invokes a function for each UTF-16 code unit in a string iterating from right to left.
*
* ## Notes
*
* - When invoked, the provided function is provided three arguments:
*
* - **value**: character.
* - **index**: character index.
* - **str**: input string.
*
* @param str - input string
* @param clbk - function to invoke
* @param thisArg - execution context
* @returns input string
*
* @example
* function log( value, index ) {
* console.log( '%d: %s', index, value );
* }
*
* forEach( 'Hello, World!', log );
*/
declare function forEachRight( str: string, clbk: Callback, thisArg?: any ): string;
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@Planeshifter We can improve the type for thisArg, correct? That will impact the callbacks above.

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@Planeshifter Planeshifter Feb 24, 2024

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@kgryte Yes, specifically making use of ThisParameterType to extract the type of the 'this' parameter of the callback function type, and then using generics for the forEachRight function that will be passed to the this parameter of the callbacks. But that is currently not done in any of the string/base packages and maybe we should address it in a follow-up PR / issue?

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That is fine. Would you mind creating an issue for this with a link to some sample code where we do use ThisParameterType? This could be a good first issue for contributors to work on.

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@kgryte Will do!



// EXPORTS //

export = forEachRight;
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