feat: add C & JS implementation of math/base/special/digammaf

[officiallyanee]

---

type: pre_commit_static_analysis_report
description: Results of running static analysis checks when committing changes. report:

• task: lint_filenames status: passed
• task: lint_editorconfig status: passed
• task: lint_markdown status: passed
• task: lint_package_json status: passed
• task: lint_repl_help status: passed
• task: lint_javascript_src status: passed
• task: lint_javascript_cli status: na
• task: lint_javascript_examples status: passed
• task: lint_javascript_tests status: passed
• task: lint_javascript_benchmarks status: passed
• task: lint_python status: na
• task: lint_r status: na
• task: lint_c_src status: passed
• task: lint_c_examples status: passed
• task: lint_c_benchmarks status: passed
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• task: lint_shell status: na
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Progresses #649

Description

What is the purpose of this pull request?

This pull request:

• adds C & JS implementation of math/base/special/digammaf

Related Issues

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This pull request has the following related issues:

• None

Questions

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No.

Other

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• Read, understood, and followed the contributing guidelines.

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@stdlib-js/reviewers

[stdlib-bot]

Coverage Report

Package	Statements	Branches	Functions	Lines
math/base/special/digammaf	$\color{red}350/354$ $\color{green}+0.51%$	$\color{red}27/29$ $\color{red}-3.32%$	$\color{green}3/3$ $\color{green}+50.00%$	$\color{red}350/354$ $\color{green}+0.51%$

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

[officiallyanee]

The issue regarding coverage: I tried to run test.native.js locally and it was running if i deleted test.js but both were not running together.
Kindly help me solve it, thanks!

[gunjjoshi]

@officiallyanee You can go through the implementation of @stdlib/math/base/special/digamma once and refactor the implementation in this PR. Currently, it seems more close to how it is in Cephes, but there are some conventions that need to be followed while implementing a function from a reference implementation.

[gunjjoshi]

The double-precision implementation uses boost, as the reference implementation, but here you have referred to Cephes. Is there any particular reason for that?

[officiallyanee]

I went through various single precision packages and saw preferred reference for single precision packages seemed to Cephes since it has a separate implementation for float32 version of functions. Is that fine?

[gunjjoshi]

We must declare only one variable per line.

[gunjjoshi]

We should avoid using goto statements. In this case, for instance, you can directly return y after conditionally decrementing nz from it, based on the value of negative.

[gunjjoshi]

Comments must end with either ... or :, here and at all other places.

[Planeshifter]

All the JavaScript files in this PR are missing spaces around function call arguments and inside control-flow parentheses. The stdlib style guide requires spaces around arguments (e.g., foo( bar ) not foo(bar)) and inside if/for/while parentheses (e.g., if ( condition ) not if (condition)).

This needs to be fixed throughout all .js files in this PR.

[Planeshifter]

The expected values from the Julia fixtures are Float64. In test.js you correctly wrap them with float64ToFloat32( expected[i] ), but here in the native tests you're comparing raw Float64 expected values against Float32 results. You should import float64ToFloat32 and wrap the expected values here too, same as in test.js. See math/base/special/lnf/test/test.native.js for a reference that does this correctly.

[Planeshifter]

This #include for stdlib/constants/float32/max.h is unused — STDLIB_CONSTANT_FLOAT32_MAX doesn't appear anywhere in the implementation. Let's remove it, and also remove @stdlib/constants/float32/max from the dependencies arrays in manifest.json.

Suggested change

#include "stdlib/constants/float32/max.h"

[Planeshifter]

This // exports: comment isn't standard for math/base/special packages. Let's remove this line.

Suggested change

// exports: { "digammaf": "main" }

[Planeshifter]

This directory is missing a src/Makefile (for cleaning build artifacts). Every stdlib C package includes one — see e.g. math/base/special/digamma/src/Makefile. You can copy it directly from any existing package since they're all identical.