feat: add blas/ext/base/ddiff

[headlessNode]

Resolves stdlib-js/metr-issue-tracker#163.

Description

What is the purpose of this pull request?

This pull request:

• add blas/ext/base/ddiff

Related Issues

Does this pull request have any related issues?

This pull request has the following related issues:

• Resolves [RFC]: add blas/ext/base/ddiff metr-issue-tracker#163

Questions

Any questions for reviewers of this pull request?

No.

Other

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No.

Checklist

Please ensure the following tasks are completed before submitting this pull request.

• Read, understood, and followed the contributing guidelines.

AI Assistance

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• No

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• Code generation (e.g., when writing an implementation or fixing a bug)
• Test/benchmark generation
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{{TODO: add disclosure if applicable}}

---

@stdlib-js/reviewers

[stdlib-bot]

Coverage Report

Package	Statements	Branches	Functions	Lines
blas/ext/base/ddiff	$\color{red}569/600$ $\color{green}+2.19%$	$\color{red}30/36$ $\color{green}+0.00%$	$\color{green}5/5$ $\color{green}+0.00%$	$\color{red}569/600$ $\color{green}+2.19%$

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

[kgryte]

@headlessNode Looks like we are missing some tests needed to get to 100% code coverage. Would you mind adding those? Cheers!

[kgryte]

Suggested change

	> {{alias}}.ndarray( x.length, 1, x, 1, 0, 1, p, 1, 0, 1, a, 1, 0, out, 1, 0, w, 1, 0 )
	<Float64Array>[ 1.0, -3.0, 4.0, 1.0 ]
	// Advanced indexing:
	> var x = new {{alias:@stdlib/array/float64}}( [ 1.0, -2.0, 2.0 ] );
	> var p = new {{alias:@stdlib/array/float64}}( [ 0.0 ] );
	> var a = new {{alias:@stdlib/array/float64}}( [ 3.0 ] );
	> var out = new {{alias:@stdlib/array/float64}}( 3 );
	> var w = new {{alias:@stdlib/array/float64}}( 3 );
	> {{alias}}.ndarray( 2, 1, x, 1, x.length-2, 1, p, 1, 0, 1, a, 1, 0, out, 1, 0, w, 1, 0 )
	> {{alias}}.ndarray( 3, 1, x,1,0, 1, p,1,0, 1, a,1,0, out,1,0, w,1,0 )
	<Float64Array>[ 1.0, -3.0, 4.0, 1.0 ]
	// Advanced indexing:
	> x = new {{alias:@stdlib/array/float64}}( [ 1.0, -2.0, 2.0 ] );
	> p = new {{alias:@stdlib/array/float64}}( [ 0.0 ] );
	> a = new {{alias:@stdlib/array/float64}}( [ 3.0 ] );
	> out = new {{alias:@stdlib/array/float64}}( 3 );
	> w = new {{alias:@stdlib/array/float64}}( 3 );
	> {{alias}}.ndarray( 2, 1, x,1,1, 1, p,1,0, 1, a,1,0, out,1,0, w,1,0 )

[kgryte]

Hopefully, this will resolve the REPL text lint failures.