feat: add constants/float16/half-ln-two

lib/node_modules/@stdlib/constants/float16/half-ln-two/README.md

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+<!--
+
+@license Apache-2.0
+
+Copyright (c) 2025 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.
+
+-->
+
+# FLOAT16_HALF_LN2
+
+> One half times the [natural logarithm][@stdlib/math/base/special/ln] of `2` as a half-precision floating-point number.
+
+<section class="usage">
+
+## Usage
+
+```javascript
+var FLOAT16_HALF_LN2 = require( '@stdlib/constants/float16/half-ln-two' );
+```
+
+#### FLOAT16_HALF_LN2
+
+One half times the [natural logarithm][@stdlib/math/base/special/ln] of `2` as a half-precision floating-point number.
+
+```javascript
+var bool = ( FLOAT16_HALF_LN2 === 0.3466796875 );
+// returns true
+```
+
+</section>
+
+<!-- /.usage -->
+
+<section class="examples">
+
+## Examples
+
+<!-- TODO: better example -->
+
+<!-- eslint no-undef: "error" -->
+
+```javascript
+var FLOAT16_HALF_LN2 = require( '@stdlib/constants/float16/half-ln-two' );
+
+console.log( FLOAT16_HALF_LN2 );
+// => 0.3466796875
+```
+
+</section>
+
+<!-- /.examples -->
+
+<!-- Section for related `stdlib` packages. Do not manually edit this section, as it is automatically populated. -->
+
+<section class="related">
+
+* * *
+
+## See Also
+
+-   <span class="package-name">[`@stdlib/constants/float32/half-ln-two`][@stdlib/constants/float32/half-ln-two]</span><span class="delimiter">: </span><span class="description">one half times the natural logarithm of 2.</span>
+
+</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">
+
+[@stdlib/math/base/special/ln]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/math/base/special/ln
+
+<!-- <related-links> -->
+
+[@stdlib/constants/float32/half-ln-two]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/constants/float32/half-ln-two
+
+<!-- </related-links> -->
+
+</section>
+
+<!-- /.links -->

lib/node_modules/@stdlib/constants/float16/half-ln-two/docs/repl.txt

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+
+{{alias}}
+    One half times the natural logarithm of 2 as a half-precision
+    floating-point number.
+
+    Examples
+    --------
+    > {{alias}}
+    0.3466796875
+
+    See Also
+    --------
+

lib/node_modules/@stdlib/constants/float16/half-ln-two/docs/types/index.d.ts

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+/*
+* @license Apache-2.0
+*
+* Copyright (c) 2025 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
+
+/**
+* One half times the natural logarithm of 2 as a half-precision floating-point number.
+*
+* @example
+* var val = FLOAT16_HALF_LN2;
+* // returns 0.3466796875
+*/
+declare const FLOAT16_HALF_LN2: number;
+
+
+// EXPORTS //
+
+export = FLOAT16_HALF_LN2;

lib/node_modules/@stdlib/constants/float16/half-ln-two/docs/types/test.ts

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+/*
+* @license Apache-2.0
+*
+* Copyright (c) 2025 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.
+*/
+
+import FLOAT16_HALF_LN2 = require( './index' );
+
+
+// TESTS //
+
+// The export is a number...
+{
+	// eslint-disable-next-line @typescript-eslint/no-unused-expressions
+	FLOAT16_HALF_LN2; // $ExpectType number
+}

lib/node_modules/@stdlib/constants/float16/half-ln-two/examples/index.js

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+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2025 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';
+
+var FLOAT16_HALF_LN2 = require( './../lib' );
+
+console.log( FLOAT16_HALF_LN2 );
+// => 0.3466796875

lib/node_modules/@stdlib/constants/float16/half-ln-two/lib/index.js

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+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2025 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';
+
+/**
+* One half times the natural logarithm of 2 as a half-precision floating-point number.
+*
+* @module @stdlib/constants/float16/half-ln-two
+* @type {number}
+*
+* @example
+* var FLOAT16_HALF_LN2 = require( '@stdlib/constants/float16/half-ln-two' );
+* // returns 0.3466796875
+*/
+
+// MAIN //
+
+/**
+* One half times the natural logarithm of 2 as a half-precision floating-point number.
+*
+* ```tex
+* \frac{\ln 2}{2}
+* ```
+*
+* @constant
+* @type {number}
+* @default 0.3466796875
+*/
+var FLOAT16_HALF_LN2 = 0.3466796875; // 0x3EB17218
+
+
+// EXPORTS //
+
+module.exports = FLOAT16_HALF_LN2;

lib/node_modules/@stdlib/constants/float16/half-ln-two/package.json

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+{
+  "name": "@stdlib/constants/float16/half-ln-two",
+  "version": "0.0.0",
+  "description": "One half times the natural logarithm of 2 as a half-precision floating-point number.",
+  "license": "Apache-2.0",
+  "author": {
+    "name": "The Stdlib Authors",
+    "url": "https://github.com/stdlib-js/stdlib/graphs/contributors"
+  },
+  "contributors": [
+    {
+      "name": "The Stdlib Authors",
+      "url": "https://github.com/stdlib-js/stdlib/graphs/contributors"
+    }
+  ],
+  "main": "./lib",
+  "directories": {
+    "doc": "./docs",
+    "example": "./examples",
+    "lib": "./lib",
+    "test": "./test"
+  },
+  "types": "./docs/types",
+  "scripts": {},
+  "homepage": "https://github.com/stdlib-js/stdlib",
+  "repository": {
+    "type": "git",
+    "url": "git://github.com/stdlib-js/stdlib.git"
+  },
+  "bugs": {
+    "url": "https://github.com/stdlib-js/stdlib/issues"
+  },
+  "dependencies": {},
+  "devDependencies": {},
+  "engines": {
+    "node": ">=0.10.0",
+    "npm": ">2.7.0"
+  },
+  "os": [
+    "aix",
+    "darwin",
+    "freebsd",
+    "linux",
+    "macos",
+    "openbsd",
+    "sunos",
+    "win32",
+    "windows"
+  ],
+  "keywords": [
+    "stdlib",
+    "stdmath",
+    "constant",
+    "const",
+    "mathematics",
+    "math",
+    "ln",
+    "ln2",
+    "half",
+    "natural",
+    "logarithm",
+    "log",
+    "ieee754",
+    "float",
+    "flt",
+    "precision",
+    "floating-point",
+    "float16"
+  ]
+}

lib/node_modules/@stdlib/constants/float16/half-ln-two/test/test.js

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+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2025 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 tape = require( 'tape' );
+var lnf = require( '@stdlib/math/base/special/lnf' );
+var absf = require( '@stdlib/math/base/special/absf' );
+var EPS = require( '@stdlib/constants/float16/eps' );
+var float64ToFloat32 = require( '@stdlib/number/float64/base/to-float16' );
+var FLOAT16_HALF_LN2 = require( './../lib' );
+
+
+// TESTS //
+
+tape( 'main export is a number', function test( t ) {
+	t.ok( true, __filename );
+	t.strictEqual( typeof FLOAT16_HALF_LN2, 'number', 'main export is a number' );
+	t.end();
+});
+
+tape( 'export is a half-precision floating-point number equal to `0.3466796875`', function test( t ) {
+	t.strictEqual( FLOAT16_HALF_LN2, float64ToFloat32( 3.46573590279972654709e-01 ), 'returns expected value' );
+	t.end();
+});
+
+tape( 'export equals `0.5*lnf(2)`', function test( t ) {
+	var delta;
+	var tol;
+	var v;
+
+	v = float64ToFloat32( 0.5 * lnf( 2.0 ) );
+	delta = absf( float64ToFloat32( v - FLOAT16_HALF_LN2 ) );
+	tol = EPS * FLOAT16_HALF_LN2;
+
+	t.ok( delta <= tol, 'equals 0.5*lnf(2) within tolerance '+tol );
+
+	t.end();
+});