feat: add C implementation for `math/base/special/heaviside` #10196

rautelaKamal · 2026-02-10T11:15:52Z

Description

This PR adds a double-precision C implementation for @stdlib/math/base/special/heaviside, following the pattern established by heavisidef.

Changes

Add C header file defining STDLIB_BASE_HEAVISIDE_CONTINUITY enum
Implement stdlib_base_heaviside in C for double-precision
Create Node-API addon bridge for JavaScript integration
Add GYP build configuration (binding.gyp, include.gypi, manifest.json)
Create lib/native.js dispatcher with string-to-enum mapping
Update lib/index.js to use native implementation when available
Update package.json to enable gypfile
Add comprehensive native test suite

Testing

All 213 native tests passing
All 2013 standard tests passing
Maintains full API compatibility with existing JavaScript implementation

Related Issues

Contributes to improving performance of mathematical functions through native C implementations.

Read, understood, and followed the contributing guidelines

- Add C header file defining STDLIB_BASE_HEAVISIDE_CONTINUITY enum - Implement stdlib_base_heaviside in C for double-precision - Create Node-API addon bridge for JavaScript integration - Add GYP build configuration (binding.gyp, include.gypi, manifest.json) - Create lib/native.js dispatcher with string-to-enum mapping - Update lib/index.js to use native implementation when available - Update package.json to enable gypfile and add src/include directories - Add comprehensive native test suite (test/test.native.js) - All tests passing (213/213 native, 2013/2013 standard) This implementation follows the pattern established by heavisidef and provides performance improvements through native C code while maintaining full API compatibility with the existing JavaScript implementation.

stdlib-bot · 2026-02-10T11:16:02Z

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stdlib-bot · 2026-02-10T11:23:58Z

Hello! Thank you for your contribution to stdlib.

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Please read our contributing guidelines.
Update your pull request description to include this checked box:

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This acknowledgment confirms that you've read the guidelines, which include:

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Your agreement to license your contributions under the project's terms

We can't review or accept contributions without this acknowledgment.

Thank you for your understanding and cooperation. We look forward to reviewing your contribution!

Planeshifter

Thanks for opening a PR! It will require a whole bunch of changes, see feedback; make sure to closely follow what was done in heavisidef.

Planeshifter · 2026-02-10T17:54:32Z

lib/node_modules/@stdlib/math/base/special/heaviside/lib/index.js

+var setReadOnly = require( '@stdlib/utils/define-read-only-property' );
 var main = require( './main.js' );
+var native = require( './native.js' );
+
+
+// MAIN //
+
+/**
+* Evaluate the Heaviside function.
+*
+* @module @stdlib/math/base/special/heaviside
+*
+* @example
+* var heaviside = require( '@stdlib/math/base/special/heaviside' );
+*
+* var v = heaviside( 3.14 );
+* // returns 1.0
+*
+* v = heaviside( -3.14 );
+* // returns 0.0
+*
+* v = heaviside( 0.0 );
+* // returns NaN
+*
+* v = heaviside( 0.0, 'half-maximum' );
+* // returns 0.5
+*
+* v = heaviside( 0.0, 'left-continuous' );
+* // returns 0.0
+*
+* v = heaviside( 0.0, 'right-continuous' );
+* // returns 1.0
+*
+* v = heaviside( NaN );
+* // returns NaN
+*/
+var heaviside;
+if (native) {
+	heaviside = native;
+} else {
+	heaviside = main;
+}
+
+setReadOnly(heaviside, 'native', native);



This is a breaking change -- require('./native.js') will unconditionally require addon.node, which throws if the native addon hasn't been compiled. Since this runs at the top level of index.js, the entire @stdlib/math/base/special/heaviside module will crash on any system that hasn't run make install-node-addons.

The established pattern (see heavisidef/lib/index.js) is to keep index.js as a simple passthrough to main.js. The native.js file should only be loaded on-demand via tryRequire in test/test.native.js and benchmark/benchmark.native.js. Please revert lib/index.js to its original form -- the whole setReadOnly, native import, and conditional selection block should be removed.

Planeshifter · 2026-02-10T17:54:42Z

lib/node_modules/@stdlib/math/base/special/heaviside/test/test.native.js

+var tape = require( 'tape' );
+var isnan = require( '@stdlib/math/base/assert/is-nan' );
+var isPositiveZero = require( '@stdlib/math/base/assert/is-positive-zero' );
+var PINF = require( '@stdlib/constants/float64/pinf' );
+var NINF = require( '@stdlib/constants/float64/ninf' );
+var EPS = require( '@stdlib/constants/float64/eps' );
+var randu = require( '@stdlib/random/base/randu' );
+var heaviside = require( './../lib/native.js' );
+


This needs the standard tryRequire/skip pattern so tests are gracefully skipped when the native addon isn't compiled. Right now this will crash the test runner. Here's the pattern from heavisidef/test/test.native.js:

var resolve = require( 'path' ).resolve; var tape = require( 'tape' ); var isnan = require( '@stdlib/math/base/assert/is-nan' ); var isPositiveZero = require( '@stdlib/math/base/assert/is-positive-zero' ); var PINF = require( '@stdlib/constants/float64/pinf' ); var NINF = require( '@stdlib/constants/float64/ninf' ); var EPS = require( '@stdlib/constants/float64/eps' ); var randu = require( '@stdlib/random/base/randu' ); var tryRequire = require( '@stdlib/utils/try-require' ); // VARIABLES // var heaviside = tryRequire( resolve( __dirname, './../lib/native.js' ) ); var opts = { 'skip': ( heaviside instanceof Error ) };

And every tape() call needs opts as the second argument, e.g.:

tape( 'main export is a function', opts, function test( t ) {

Planeshifter · 2026-02-10T17:54:52Z

lib/node_modules/@stdlib/math/base/special/heaviside/test/test.native.js

+
+// TESTS //
+
+tape('main export is a function', function test(t) {


The stdlib style requires spaces inside parentheses for function calls. This pattern applies throughout the file -- tape(, t.ok(, t.strictEqual(, heaviside(, isnan(, for (, etc. should all have spaces inside parens:

Suggested change

tape('main export is a function', function test(t) {

tape( 'main export is a function', function test( t ) {

Please update all function calls in this file to use the stdlib spacing convention. Compare with the reference heavisidef/test/test.native.js for the correct formatting.

Planeshifter · 2026-02-10T17:55:02Z

lib/node_modules/@stdlib/math/base/special/heaviside/lib/native.js

+function heaviside(x, continuity) {
+	var c = CONTINUITY[continuity];
+	if (c === void 0) {
+		c = 3; // Discontinuous
+	}
+	return addon(x, c);
+}


A few things here:

Spacing: stdlib requires spaces inside parentheses for function calls and conditionals. function heaviside(x, continuity) should be function heaviside( x, continuity ), if (c === void 0) should be if ( c === void 0 ), and addon(x, c) should be addon( x, c ).

Missing str2enum pattern: The reference heavisidef uses separate str2enum.js and enum.js modules for the string-to-enum mapping. The inline CONTINUITY object is missing the 'discontinuous' key, and doesn't distinguish between an explicitly-passed 'discontinuous' and a completely invalid string like 'garbage' -- both silently map to c = 3. The reference handles this properly by returning -1 for unknown strings, which hits the default case in the C switch.

Planeshifter · 2026-02-10T17:55:09Z

lib/node_modules/@stdlib/math/base/special/heaviside/manifest.json

+{
+    "options": {
+        "task": "build"
+    },
+    "fields": [
+        {


This file uses 4-space indentation, but stdlib JSON files require 2-space indentation per the .editorconfig. Compare with the reference heavisidef/manifest.json which uses 2 spaces. Please re-indent the entire file.

stdlib-bot · 2026-02-10T18:00:39Z

Coverage Report

No coverage information available.

@Planeshifter

- Revert lib/index.js to simple passthrough pattern - Create separate lib/enum.js and lib/str2enum.js modules - Update lib/native.js to use str2enum with proper spacing conventions - Fix test/test.native.js with tryRequire pattern and stdlib spacing - All tests passing (213/213 native, 2013/2013 standard) Follows pattern established in heavisidef as requested by @Planeshifter

rautelaKamal · 2026-02-10T23:18:36Z

Hi @Planeshifter, thanks for the detailed review!

I've pushed a new commit (37d321c) that addresses your feedback:

Reverted the changes to
lib/index.js
(it no longer unconditionally requires the native addon).
Updated
test/test.native.js
to use the tryRequire pattern.
Moved the string-to-enum mapping into lib/str2enum.js and lib/enum.js.
Fixed the indentation in manifest.json and added spaces inside parentheses as requested.

Planeshifter

Left another round of feedback. Please make sure you have EditorConfig and linting setup locally (run make init to register the Git hooks and other setup).

Planeshifter · 2026-02-11T04:28:03Z

lib/node_modules/@stdlib/math/base/special/heaviside/lib/native.js

+var addon = require('./../src/addon.node');
+var str2enum = require('./str2enum.js');


stdlib requires spaces inside parentheses for all function calls, including require(). This applies throughout all JS files in this PR (native.js, str2enum.js, enum.js, index.js, test.native.js).

Compare with the reference heavisidef/lib/native.js:

Suggested change

var addon = require('./../src/addon.node');

var str2enum = require('./str2enum.js');

var addon = require( './../src/addon.node' );

var str2enum = require( './str2enum.js' );

Planeshifter · 2026-02-11T04:28:05Z

lib/node_modules/@stdlib/math/base/special/heaviside/lib/native.js

+function heaviside(x, continuity) {
+	return addon(x, str2enum(continuity));
+}


Same spacing rule applies to function definitions and calls - need spaces inside parens:

Suggested change

function heaviside(x, continuity) {

return addon(x, str2enum(continuity));

}

function heaviside( x, continuity ) {

return addon( x, str2enum( continuity ) );

}

Planeshifter · 2026-02-11T04:28:12Z

lib/node_modules/@stdlib/math/base/special/heaviside/lib/enum.js

+function enumeration() {
+    return {
+        // Half-maximum:
+        'half-maximum': 0,
+
+        // Left-continuous:
+        'left-continuous': 1,
+
+        // Right-continuous:
+        'right-continuous': 2,
+
+        // Discontinuous:
+        'discontinuous': 3
+    };
+}


This file uses 4-space indentation, but stdlib JS files must use TAB indentation per the .editorconfig. Compare with heavisidef/lib/enum.js which uses tabs.

Suggested change

function enumeration() {

return {

// Half-maximum:

'half-maximum': 0,

// Left-continuous:

'left-continuous': 1,

// Right-continuous:

'right-continuous': 2,

// Discontinuous:

'discontinuous': 3

};

}

function enumeration() {

return {

// Half-maximum:

'half-maximum': 0,

// Left-continuous:

'left-continuous': 1,

// Right-continuous:

'right-continuous': 2,

// Discontinuous:

'discontinuous': 3

};

}

Planeshifter · 2026-02-11T04:28:14Z

lib/node_modules/@stdlib/math/base/special/heaviside/lib/str2enum.js

+
+// MODULES //
+
+var enumeration = require('./enum.js');


Missing spaces in require():

Suggested change

var enumeration = require('./enum.js');

var enumeration = require( './enum.js' );

Planeshifter · 2026-02-11T04:28:18Z

lib/node_modules/@stdlib/math/base/special/heaviside/lib/str2enum.js

+function str2enum(ctype) {
+    var v = ENUM[ctype];
+    return (typeof v === 'number') ? v : -1; // note: we include this guard to prevent walking the prototype chain
+}


Same two issues here: 4-space indentation should be TABs, and function call/definition needs spaces inside parens. Compare with heavisidef/lib/str2enum.js:

Suggested change

function str2enum(ctype) {

var v = ENUM[ctype];

return (typeof v === 'number') ? v : -1; // note: we include this guard to prevent walking the prototype chain

}

function str2enum( ctype ) {

var v = ENUM[ ctype ];

return ( typeof v === 'number' ) ? v : -1; // note: we include this guard to prevent walking the prototype chain

}

Planeshifter · 2026-02-11T04:28:24Z

lib/node_modules/@stdlib/math/base/special/heaviside/lib/index.js

 // MODULES //

-var main = require( './main.js' );
+var main = require('./main.js');


This line had correct spacing before and was changed to remove the spaces. Let's restore it:

Suggested change

var main = require('./main.js');

var main = require( './main.js' );

Planeshifter · 2026-02-11T04:28:26Z

lib/node_modules/@stdlib/math/base/special/heaviside/manifest.json

+{
+    "options": {
+        "task": "build"
+    },
+    "fields": [


JSON files must use 2-space indentation per the .editorconfig. This file uses 4-space indentation throughout. Compare with heavisidef/manifest.json which uses 2 spaces. The entire file needs to be re-indented.

Planeshifter · 2026-02-11T04:28:33Z

lib/node_modules/@stdlib/math/base/special/heaviside/test/test.native.js

+var resolve = require('path').resolve;
+var tape = require('tape');
+var isnan = require('@stdlib/math/base/assert/is-nan');
+var isPositiveZero = require('@stdlib/math/base/assert/is-positive-zero');
+var PINF = require('@stdlib/constants/float64/pinf');
+var NINF = require('@stdlib/constants/float64/ninf');
+var EPS = require('@stdlib/constants/float64/eps');
+var randu = require('@stdlib/random/base/randu');
+var tryRequire = require('@stdlib/utils/try-require');


All require() calls and function calls in this file are missing spaces inside parentheses. This is a pervasive issue throughout the entire test file - every require(...), tape(...), resolve(...), tryRequire(...), heaviside(...), isnan(...), isPositiveZero(...), t.ok(...), t.strictEqual(...), t.end(), etc. needs spaces.

For example, these lines should be:

var resolve = require( 'path' ).resolve; var tape = require( 'tape' ); var isnan = require( '@stdlib/math/base/assert/is-nan' ); var isPositiveZero = require( '@stdlib/math/base/assert/is-positive-zero' ); var PINF = require( '@stdlib/constants/float64/pinf' ); var NINF = require( '@stdlib/constants/float64/ninf' ); var EPS = require( '@stdlib/constants/float64/eps' ); var randu = require( '@stdlib/random/base/randu' ); var tryRequire = require( '@stdlib/utils/try-require' );

Please apply this spacing fix throughout the entire file. The reference file heavisidef/test/test.native.js shows the correct pattern.

Planeshifter · 2026-02-11T04:28:42Z

lib/node_modules/@stdlib/math/base/special/heaviside/package.json

@@ -14,11 +14,14 @@
    }
  ],
  "main": "./lib",


The C implementation is missing several files that are required per stdlib conventions. Comparing with the reference package heavisidef, the following are absent:

benchmark/benchmark.native.js - JS benchmark for the native addon

benchmark/c/native/benchmark.c + Makefile - C benchmark for the stdlib native implementation

examples/c/example.c + Makefile - C usage example

README.md C APIs section - documentation for the C function signature and enum types

All of these exist in the heavisidef package and are standard requirements when adding a C implementation.

rautelaKamal · 2026-02-11T06:42:14Z

I've applied the requested style fixes (indentation, spaces in parentheses) and verified that tests pass locally. Ready for review

stdlib-bot added the Math Issue or pull request specific to math functionality. label Feb 10, 2026

stdlib-bot added First-time Contributor A pull request from a contributor who has never previously committed to the project repository. Needs Review A pull request which needs code review. labels Feb 10, 2026

Planeshifter changed the title ~~Add C implementation for @stdlib/math/base/special/heaviside~~ feat: add C implementation for math/base/special/heaviside Feb 10, 2026

Planeshifter requested changes Feb 10, 2026

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Planeshifter added Needs Changes Pull request which needs changes before being merged. and removed Needs Review A pull request which needs code review. labels Feb 10, 2026

rautelaKamal requested a review from Planeshifter February 10, 2026 22:59

stdlib-bot added the Needs Review A pull request which needs code review. label Feb 10, 2026

Planeshifter requested changes Feb 11, 2026

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Planeshifter removed the Needs Review A pull request which needs code review. label Feb 11, 2026

style: fix indentation and add spaces in parentheses

7da0604

rautelaKamal requested a review from Planeshifter February 11, 2026 06:42

stdlib-bot added the Needs Review A pull request which needs code review. label Feb 11, 2026


		// TESTS //

		tape('main export is a function', function test(t) {

	tape('main export is a function', function test(t) {
	tape( 'main export is a function', function test( t ) {

		var addon = require('./../src/addon.node');
		var str2enum = require('./str2enum.js');

	var enumeration = require('./enum.js');
	var enumeration = require( './enum.js' );

	var main = require('./main.js');
	var main = require( './main.js' );

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Getting Started

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Running Tests Locally

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feat: add C implementation for `math/base/special/heaviside` #10196

feat: add C implementation for `math/base/special/heaviside` #10196

rautelaKamal commented Feb 10, 2026 •

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