feat: add ndarray/base/scalar-dtype

lib/node_modules/@stdlib/ndarray/base/atleastnd/lib/main.js

@@ -21,10 +21,6 @@
 // MODULES //
 
 var isndarrayLike = require( '@stdlib/assert/is-ndarray-like' );
-var isNumber = require( '@stdlib/assert/is-number' ).isPrimitive;
-var isComplexLike = require( '@stdlib/assert/is-complex-like' );
-var isBoolean = require( '@stdlib/assert/is-boolean' ).isPrimitive;
-var complexDataType = require( '@stdlib/complex/dtype' );
 var broadcastScalar = require( '@stdlib/ndarray/base/broadcast-scalar' );
 var dims = require( '@stdlib/ndarray/base/ndims' );
 var defaults = require( '@stdlib/ndarray/defaults' );
@@ -34,15 +30,13 @@ var getStrides = require( '@stdlib/ndarray/base/strides' );
 var getOffset = require( '@stdlib/ndarray/base/offset' );
 var getOrder = require( '@stdlib/ndarray/base/order' );
 var getDType = require( '@stdlib/ndarray/base/dtype' );
+var scalarDType = require( '@stdlib/ndarray/base/scalar-dtype' );
 var getData = require( '@stdlib/ndarray/base/data-buffer' );
 var ones = require( '@stdlib/array/base/ones' );
 
 
 // VARIABLES //
 
-var DEFAULT_REAL = defaults.get( 'dtypes.real_floating_point' );
-var DEFAULT_CMPLX = defaults.get( 'dtypes.complex_floating_point' );
-var DEFAULT_BOOL = defaults.get( 'dtypes.boolean' );
 var ORDER = defaults.get( 'order' );
 
 
@@ -108,18 +102,7 @@ function atleastnd( ndims, arrays ) {
 			continue;
 		}
 		// For scalar values, resolve a corresponding ndarray data type...
-		if ( isNumber( v ) ) { // TODO: consider abstracting this logic to an `ndarray/base/scalar-dtype` (???) package, as this logic is found elsewhere (e.g., `ndarray/from-scalar`) and it would be good to avoid duplication, especially as we add support for more ndarray data types
-			dt = DEFAULT_REAL;
-		} else if ( isBoolean( v ) ) {
-			dt = DEFAULT_BOOL;
-		} else if ( isComplexLike( v ) ) {
-			dt = complexDataType( v );
-			if ( dt === null ) {
-				dt = DEFAULT_CMPLX;
-			}
-		} else {
-			dt = 'generic';
-		}
+		dt = scalarDType(v);
 		out.push( broadcastScalar( v, dt, ones( ndims ), ORDER ) );
 	}
 	return out;

lib/node_modules/@stdlib/ndarray/base/lib/index.js

@@ -1084,6 +1084,15 @@ setReadOnly( ns, 'reverse', require( '@stdlib/ndarray/base/reverse' ) );
 */
 setReadOnly( ns, 'reverseDimension', require( '@stdlib/ndarray/base/reverse-dimension' ) );
 
+/**
+* @name scalarDType
+* @memberof ns
+* @readonly
+* @type {Function}
+* @see {@link module:@stdlib/ndarray/base/scalar-dtype}
+*/
+setReadOnly( ns, 'scalarDType', require( '@stdlib/ndarray/base/scalar-dtype' ) );
+
 /**
 * @name serializeMetaData
 * @memberof ns

lib/node_modules/@stdlib/ndarray/base/scalar-dtype/README.md

@@ -0,0 +1,147 @@
+<!--
+
+@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.
+
+-->
+
+# scalar-dtype
+
+> Return the default [ndarray][@stdlib/ndarray/base/ctor] data type for a given scalar value.
+
+<!-- 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 scalarDType = require( '@stdlib/ndarray/base/scalar-dtype' );
+```
+
+#### scalarDType( value )
+
+Returns the default [ndarray][@stdlib/ndarray/base/ctor] data type for a given scalar value.
+
+```javascript
+var dt = scalarDType( 3.14 );
+// returns 'float64'
+
+dt = scalarDType( true );
+// returns 'bool'
+
+dt = scalarDType( 'hello' );
+// returns 'generic'
+```
+
+</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 the `value`
+
+-   is a number, returns the default real-valued floating-point data type.
+-   is a boolean, returns the default boolean data type.
+-   is a complex number object of a known complex data type, returns the data type.
+-   is a complex number object of an unknown complex data type, returns the default complex-valued floating-point data type.
+-   is any other value type, returns `'generic'`.
+
+</section>
+
+<!-- /.notes -->
+
+<!-- Package usage examples. -->
+
+<section class="examples">
+
+## Examples
+
+<!-- eslint no-undef: "error" -->
+
+```javascript
+var Complex64 = require( '@stdlib/complex/float32/ctor' );
+var Complex128 = require( '@stdlib/complex/float64/ctor' );
+var scalarDType = require( '@stdlib/ndarray/base/scalar-dtype' );
+
+// Number:
+var dt = scalarDType( 3.14 );
+console.log( dt );
+// => 'float64'
+
+// Boolean:
+dt = scalarDType( true );
+console.log( dt );
+// => 'bool'
+
+// Known complex dtype (complex64):
+dt = scalarDType( new Complex64( 1.0, 2.0 ) );
+console.log( dt );
+// => 'complex64'
+
+// Known complex dtype (complex128):
+dt = scalarDType( new Complex128( 1.0, 2.0 ) );
+console.log( dt );
+// => 'complex128'
+
+// Generic fallback:
+dt = scalarDType( 'hello' );
+console.log( dt );
+// => 'generic'
+```
+
+</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/base/ctor]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/ndarray/base/ctor
+
+</section>
+
+<!-- /.links -->

lib/node_modules/@stdlib/ndarray/base/scalar-dtype/benchmark/benchmark.js

@@ -0,0 +1,56 @@
+/**
+* @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.
+*/
+
+'use strict';
+
+// MODULES //
+
+var bench = require( '@stdlib/bench' );
+var Complex64 = require( '@stdlib/complex/float32/ctor' );
+var pkg = require( './../package.json' ).name;
+var scalarDType = require( './../lib' );
+
+
+// MAIN //
+
+bench( pkg, function benchmark( b ) {
+	var values;
+	var dt;
+	var i;
+
+	values = [
+		3.14,
+		true,
+		new Complex64( 1.0, 2.0 ),
+		'hello'
+	];
+
+	b.tic();
+	for ( i = 0; i < b.iterations; i++ ) {
+		dt = scalarDType( values[ i%values.length ] );
+		if ( typeof dt !== 'string' ) {
+			b.fail( 'should return a string' );
+		}
+	}
+	b.toc();
+	if ( typeof dt !== 'string' ) {
+		b.fail( 'should return a string' );
+	}
+	b.pass( 'benchmark finished' );
+	b.end();
+});

lib/node_modules/@stdlib/ndarray/base/scalar-dtype/docs/repl.txt

@@ -0,0 +1,22 @@
+
+{{alias}}( value )
+    Returns the default ndarray data type for a given scalar value.
+
+    Parameters
+    ----------
+    value: scalar
+        Input scalar.
+
+    Returns
+    -------
+    dt: string
+        ndarray data type.
+
+    Examples
+    --------
+    > var dt = {{alias}}( 3.14 )
+    'float64'
+
+    See Also
+    --------
+

lib/node_modules/@stdlib/ndarray/base/scalar-dtype/docs/types/index.d.ts

@@ -0,0 +1,46 @@
+/*
+* @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.
+*/
+
+// TypeScript Version: 4.1
+
+/// <reference types="@stdlib/types"/>
+
+/**
+* Returns the number of ndarray dimensions.
+*
+* @param value - input scalar
+* @returns ndarray data type
+*
+* @example
+* var dt = scalarDType( 3.14 );
+* // returns 'float64'
+*
+* @example
+* var dt = scalarDType( true );
+* // returns 'bool'
+*
+* @example
+* var dt = scalarDType( 'hello' );
+* // returns 'generic'
+*/
+declare function scalarDType( value: any ): string;
+
+
+// EXPORTS //
+
+export = scalarDType;

lib/node_modules/@stdlib/ndarray/base/scalar-dtype/docs/types/test.ts

@@ -0,0 +1,40 @@
+/*
+* @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.
+*/
+
+import Complex64 = require( '@stdlib/complex/float32/ctor' );
+import Complex128 = require( '@stdlib/complex/float64/ctor' );
+import scalarDType = require( './index' );
+
+
+// TESTS //
+
+// The function returns a string...
+{
+	scalarDType( 3.14 ); // $ExpectType string
+	scalarDType( true ); // $ExpectType string
+	scalarDType( new Complex64( 1.0, 2.0 ) ); // $ExpectType string
+	scalarDType( new Complex128( 1.0, 2.0 ) ); // $ExpectType string
+	scalarDType( 'hello' ); // $ExpectType string
+}
+
+
+// The compiler throws an error if the function is provided an unsupported number of arguments...
+{
+	scalarDType(); // $ExpectError
+	scalarDType( 3.14, {} ); // $ExpectError
+}