feat: add plot/vega/base/assert/is-discrete-scale

lib/node_modules/@stdlib/plot/vega/base/assert/is-discrete-scale/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.
+
+-->
+
+# isDiscreteScale
+
+> Test if an input value is a [discrete scale][@stdlib/plot/vega/scale/discrete].
+
+<!-- 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 isDiscreteScale = require( '@stdlib/plot/vega/base/assert/is-discrete-scale' );
+```
+
+#### isDiscreteScale( value )
+
+Tests if an input value is a [discrete scale][@stdlib/plot/vega/scale/discrete].
+
+```javascript
+var DiscreteScale = require( '@stdlib/plot/vega/scale/discrete' );
+
+var v = new DiscreteScale({
+    'name': 'xScale',
+    'type': 'ordinal'
+});
+var bool = isDiscreteScale( v );
+// returns true
+
+bool = isDiscreteScale( {} );
+// returns false
+```
+
+</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">
+
+</section>
+
+<!-- /.notes -->
+
+<!-- Package usage examples. -->
+
+<section class="examples">
+
+## Examples
+
+<!-- eslint no-undef: "error" -->
+
+```javascript
+var DiscreteScale = require( '@stdlib/plot/vega/scale/discrete' );
+var isDiscreteScale = require( '@stdlib/plot/vega/base/assert/is-discrete-scale' );
+
+var v = new DiscreteScale({
+    'name': 'xScale',
+    'type': 'ordinal'
+});
+var bool = isDiscreteScale( v );
+// returns true
+
+bool = isDiscreteScale( {} );
+// returns false
+
+bool = isDiscreteScale( 'foo' );
+// returns false
+```
+
+</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/plot/vega/scale/discrete]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/plot/vega/scale/discrete
+
+</section>
+
+<!-- /.links -->

lib/node_modules/@stdlib/plot/vega/base/assert/is-discrete-scale/benchmark/benchmark.js

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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.
+*/
+
+'use strict';
+
+// MODULES //
+
+var bench = require( '@stdlib/bench' );
+var isBoolean = require( '@stdlib/assert/is-boolean' ).isPrimitive;
+var DiscreteScale = require( '@stdlib/plot/vega/scale/discrete' );
+var pkg = require( './../package.json' ).name;
+var isDiscreteScale = require( './../lib' );
+
+
+// MAIN //
+
+bench( pkg+'::true', function benchmark( b ) {
+	var values;
+	var out;
+	var v;
+	var i;
+
+	values = [
+		new DiscreteScale({
+			'name': 'xScale',
+			'type': 'ordinal'
+		}),
+		new DiscreteScale({
+			'name': 'yScale',
+			'type': 'ordinal'
+		})
+	];
+
+	b.tic();
+	for ( i = 0; i < b.iterations; i++ ) {
+		v = values[ i%values.length ];
+		out = isDiscreteScale( v );
+		if ( typeof out !== 'boolean' ) {
+			b.fail( 'should return a boolean' );
+		}
+	}
+	b.toc();
+	if ( !isBoolean( out ) ) {
+		b.fail( 'should return a boolean' );
+	}
+	b.pass( 'benchmark finished' );
+	b.end();
+});
+
+bench( pkg+'::false', function benchmark( b ) {
+	var values;
+	var out;
+	var v;
+	var i;
+
+	values = [
+		'foo',
+		'bar',
+		'',
+		'beep',
+		'boop',
+		[],
+		{}
+	];
+
+	b.tic();
+	for ( i = 0; i < b.iterations; i++ ) {
+		v = values[ i%values.length ];
+		out = isDiscreteScale( v );
+		if ( typeof out !== 'boolean' ) {
+			b.fail( 'should return a boolean' );
+		}
+	}
+	b.toc();
+	if ( !isBoolean( out ) ) {
+		b.fail( 'should return a boolean' );
+	}
+	b.pass( 'benchmark finished' );
+	b.end();
+});

lib/node_modules/@stdlib/plot/vega/base/assert/is-discrete-scale/docs/repl.txt

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+
+{{alias}}( value )
+    Tests if an input value is a discrete scale instance.
+
+    Parameters
+    ----------
+    value: any
+        Value to test.
+
+    Returns
+    -------
+    bool: boolean
+        Boolean indicating if an input value is a discrete scale instance.
+
+    Examples
+    --------
+    > var opts = { 'name': 'xScale', 'type': 'ordinal' };
+    > var v = new {{alias:@stdlib/plot/vega/scale/discrete}}( opts );
+    > var bool = {{alias}}( v )
+    true
+    > bool = {{alias}}( {} )
+    false
+
+    See Also
+    --------
+

lib/node_modules/@stdlib/plot/vega/base/assert/is-discrete-scale/docs/types/index.d.ts

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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.
+*/
+
+// TypeScript Version: 4.1
+
+/**
+* Tests whether an input value is a discrete scale instance.
+*
+* @param v - value to test
+* @returns boolean indicating whether an input value is a discrete scale instance
+*
+* @example
+* var DiscreteScale = require( '@stdlib/plot/vega/scale/discrete' );
+*
+* var v = new DiscreteScale({
+*     'name': 'xScale',
+*     'type': 'ordinal'
+* });
+* var bool = isDiscreteScale( v );
+* // returns true
+*
+* bool = isDiscreteScale( {} );
+* // returns false
+*
+* bool = isDiscreteScale( 'foo' );
+* // returns false
+*/
+declare function isDiscreteScale( v: any ): boolean;
+
+
+// EXPORTS //
+
+export = isDiscreteScale;

lib/node_modules/@stdlib/plot/vega/base/assert/is-discrete-scale/docs/types/test.ts

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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.
+*/
+
+import isDiscreteScale = require( './index' );
+
+
+// TESTS //
+
+// The function returns a boolean...
+{
+	isDiscreteScale( {} ); // $ExpectType boolean
+	isDiscreteScale( 'foo' ); // $ExpectType boolean
+}
+
+// The compiler throws an error if the function is provided an unsupported number of arguments...
+{
+	isDiscreteScale(); // $ExpectError
+	isDiscreteScale( undefined, 123 ); // $ExpectError
+}

lib/node_modules/@stdlib/plot/vega/base/assert/is-discrete-scale/examples/index.js

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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.
+*/
+
+'use strict';
+
+var DiscreteScale = require( '@stdlib/plot/vega/scale/discrete' );
+var isDiscreteScale = require( './../lib' );
+
+var v = new DiscreteScale({
+	'name': 'xScale',
+	'type': 'ordinal'
+});
+var bool = isDiscreteScale( v );
+console.log( bool );
+// => true
+
+bool = isDiscreteScale( {} );
+console.log( bool );
+// => false
+
+bool = isDiscreteScale( 'foo' );
+console.log( bool );
+// => false