feat: add ndarray/broadcast-scalar

PR-URL: #9916
Closes: stdlib-js/metr-issue-tracker#166
Co-authored-by: Athan Reines <kgryte@gmail.com>
Reviewed-by: Athan Reines <kgryte@gmail.com>

Author: headlessNode

lib/node_modules/@stdlib/ndarray/broadcast-scalar/README.md

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+<!--
+
+@license Apache-2.0
+
+Copyright (c) 2026 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.
+
+-->
+
+# broadcastScalar
+
+> Broadcast a scalar value to an [ndarray][@stdlib/ndarray/ctor] of a specified shape.
+
+<!-- Section to include introductory text. Make sure to keep an empty line after the intro `section` element and another before the `/section` close. -->
+
+<section class="intro">
+
+</section>
+
+<!-- /.intro -->
+
+<!-- Package usage documentation. -->
+
+<section class="usage">
+
+## Usage
+
+```javascript
+var broadcastScalar = require( '@stdlib/ndarray/broadcast-scalar' );
+```
+
+#### broadcastScalar( value, shape\[, options] )
+
+Broadcasts a scalar value to an [ndarray][@stdlib/ndarray/ctor] of a specified shape.
+
+```javascript
+var getDType = require( '@stdlib/ndarray/dtype' );
+
+var x = broadcastScalar( 1.0, [ 2, 2 ] );
+// returns <ndarray>[ [ 1.0, 1.0 ], [ 1.0, 1.0 ] ]
+
+var dt = String( getDType( x ) );
+// returns 'float64'
+```
+
+The function accepts the following arguments:
+
+-   **value**: scalar value.
+-   **shape**: shape of the output [ndarray][@stdlib/ndarray/ctor].
+
+The function accepts the following options:
+
+-   **dtype**: output array [data type][@stdlib/ndarray/dtypes].
+-   **order**: array order (i.e., memory layout). Must be either `row-major` (C-style) or `column-major` (Fortran-style). Default: `'row-major'`.
+-   **readonly**: boolean indicating whether an array should be **read-only**. Default: `false`.
+
+If a `dtype` option is not provided and `value`
+
+-   is a number, the default [data type][@stdlib/ndarray/dtypes] is the [default][@stdlib/ndarray/defaults] real-valued floating-point data type.
+-   is a boolean, the default [data type][@stdlib/ndarray/dtypes] is the [default][@stdlib/ndarray/defaults] boolean data type.
+-   is a complex number object of a known data type, the data type is the same as the provided value.
+-   is a complex number object of an unknown data type, the default [data type][@stdlib/ndarray/dtypes] is the [default][@stdlib/ndarray/defaults] complex-valued floating-point data type.
+-   is any other value type, the default [data type][@stdlib/ndarray/dtypes] is `'generic'`.
+
+To explicitly specify the [data type][@stdlib/ndarray/dtypes] of the returned [ndarray][@stdlib/ndarray/ctor], provide a `dtype` option.
+
+```javascript
+var getDType = require( '@stdlib/ndarray/dtype' );
+
+var x = broadcastScalar( 1.0, [ 2, 2 ], {
+    'dtype': 'float32'
+});
+// returns <ndarray>[ [ 1.0, 1.0 ], [ 1.0, 1.0 ] ]
+
+var dt = String( getDType( x ) );
+// returns 'float32'
+```
+
+</section>
+
+<!-- /.usage -->
+
+<!-- Package usage notes. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->
+
+<section class="notes">
+
+## Notes
+
+-   If `value` is a number and [`dtype`][@stdlib/ndarray/dtypes] is a complex [data type][@stdlib/ndarray/dtypes], the function returns an [ndarray][@stdlib/ndarray/ctor] containing a complex number whose real component equals the provided scalar `value` and whose imaginary component is zero.
+-   The function does not guard against precision loss when `value` is a number and the `dtype` argument is an integer [data type][@stdlib/ndarray/dtypes].
+
+</section>
+
+<!-- /.notes -->
+
+<!-- Package usage examples. -->
+
+<section class="examples">
+
+## Examples
+
+<!-- eslint no-undef: "error" -->
+
+```javascript
+var dtypes = require( '@stdlib/ndarray/dtypes' );
+var broadcastScalar = require( '@stdlib/ndarray/broadcast-scalar' );
+
+// Get a list of data types:
+var dt = dtypes( 'integer_and_generic' );
+
+// Generate zero-dimensional arrays...
+var x;
+var i;
+for ( i = 0; i < dt.length; i++ ) {
+    x = broadcastScalar( i, [ 2, 2 ], {
+        'dtype': dt[ i ]
+    });
+    console.log( x.get( 0, 1 ) );
+}
+```
+
+</section>
+
+<!-- /.examples -->
+
+<!-- Section to include cited references. If references are included, add a horizontal rule *before* the section. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->
+
+<section class="references">
+
+</section>
+
+<!-- /.references -->
+
+<!-- Section for related `stdlib` packages. Do not manually edit this section, as it is automatically populated. -->
+
+<section class="related">
+
+</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/ndarray/ctor]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/ndarray/ctor
+
+[@stdlib/ndarray/dtypes]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/ndarray/dtypes
+
+[@stdlib/ndarray/defaults]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/ndarray/defaults
+
+<!-- <related-links> -->
+
+<!-- </related-links> -->
+
+</section>
+
+<!-- /.links -->