[RFC]: add `@stdlib/iter/cunone-by`

[kgryte]

Description

This RFC proposes adding the package @stdlib/iter/cunone-by, which cumulatively tests whether no iterated value passes a test implemented by a predicate function. The returned iterator should be a transform iterator, continuing to iterate while source iterator values are available.

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

function isPositive( value ) {
    return ( value > 0 );
}

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

var it = iterCuNoneBy( arr, isPositive );

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 predicate function should be provided two arguments:

• value: the iterated value.
• index: iteration index (zero-based).

Related Issues

No.

Questions

No.

Other

• See also @stdlib/iter/none-by

Checklist

• [X] I have read and understood the Code of Conduct.
• [X] Searched for existing issues and pull requests.
• [X] The issue name begins with RFC:.

[Ad11xx]

Hi @kgryte , can I solve this?

[kgryte]

@Ad11xx Thanks for volunteering to work on this. Please feel free to submit a PR implementing this feature.

[Ad11xx]

Thanks a lot! if it is possible is there any file I can refer to regarding the code practices?

[kgryte]

Yes, you should look at both @stdlib/iter/none-by (which is a sink iterator) and @stdlib/iter/for-each, which is a transform iterator. The package you are planning to add should be a combination of the two.