feat: add plot/vega/signal/names

lib/node_modules/@stdlib/plot/vega/signal/names/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.
+
+-->
+
+# signals
+
+> List of reserved Vega signal names.
+
+<!-- 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 signals = require( '@stdlib/plot/vega/signal/names' );
+```
+
+#### signals( \[kind] )
+
+Returns a list of reserved signal names.
+
+```javascript
+var out = signals();
+// e.g., returns [ 'datum', 'event', ... ]
+```
+
+The function has the following parameters:
+
+-   **kind**: signal kind. Must be one of the following:
+
+    -   `'all'`: all signal names (default).
+    -   `'reserved'`: reserved signal names.
+    -   `'built_in'`: built-in signal names.
+    -   `'special'`: special signal names.
+
+By default, the function returns all signal names. To return only those signals of a specified kind, provide a `kind` argument.
+
+```javascript
+var out = signals( 'reserved' );
+// e.g., returns [ 'datum', 'event', 'item', 'parent' ]
+```
+
+</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 contains = require( '@stdlib/array/base/assert/contains' ).factory;
+var signals = require( '@stdlib/plot/vega/signal/names' );
+
+var isSignal = contains( signals() );
+
+var bool = isSignal( 'datum' );
+// returns true
+
+bool = isSignal( 'width' );
+// returns true
+
+bool = isSignal( 'beep' );
+// returns false
+
+bool = isSignal( 'boop' );
+// 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">
+
+</section>
+
+<!-- /.links -->

lib/node_modules/@stdlib/plot/vega/signal/names/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 isStringArray = require( '@stdlib/assert/is-string-array' ).primitives;
+var pkg = require( './../package.json' ).name;
+var signals = require( './../lib' );
+
+
+// MAIN //
+
+bench( pkg, function benchmark( b ) {
+	var out;
+	var i;
+
+	b.tic();
+	for ( i = 0; i < b.iterations; i++ ) {
+		out = signals();
+		if ( out.length < 2 ) {
+			b.fail( 'should return an array' );
+		}
+	}
+	b.toc();
+	if ( !isStringArray( out ) ) {
+		b.fail( 'should return an array of strings' );
+	}
+	b.pass( 'benchmark finished' );
+	b.end();
+});
+
+bench( pkg+':kind=reserved', function benchmark( b ) {
+	var out;
+	var i;
+
+	b.tic();
+	for ( i = 0; i < b.iterations; i++ ) {
+		out = signals( 'reserved' );
+		if ( out.length < 2 ) {
+			b.fail( 'should return an array' );
+		}
+	}
+	b.toc();
+	if ( !isStringArray( out ) ) {
+		b.fail( 'should return an array of strings' );
+	}
+	b.pass( 'benchmark finished' );
+	b.end();
+});
+
+bench( pkg+':kind=built_in', function benchmark( b ) {
+	var out;
+	var i;
+
+	b.tic();
+	for ( i = 0; i < b.iterations; i++ ) {
+		out = signals( 'built_in' );
+		if ( out.length < 2 ) {
+			b.fail( 'should return an array' );
+		}
+	}
+	b.toc();
+	if ( !isStringArray( out ) ) {
+		b.fail( 'should return an array of strings' );
+	}
+	b.pass( 'benchmark finished' );
+	b.end();
+});
+
+bench( pkg+':kind=special', function benchmark( b ) {
+	var out;
+	var i;
+
+	b.tic();
+	for ( i = 0; i < b.iterations; i++ ) {
+		out = signals( 'special' );
+		if ( out.length < 1 ) {
+			b.fail( 'should return an array' );
+		}
+	}
+	b.toc();
+	if ( !isStringArray( out ) ) {
+		b.fail( 'should return an array of strings' );
+	}
+	b.pass( 'benchmark finished' );
+	b.end();
+});

lib/node_modules/@stdlib/plot/vega/signal/names/docs/repl.txt

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+
+{{alias}}( [kind] )
+    Returns a list of reserved signal names.
+
+    Parameters
+    ----------
+    kind: string (optional)
+        Signal kind. Must be one of the following:
+
+        - all: all signal names (default).
+        - reserved: reserved signal names.
+        - built_in: built-in signal names.
+        - special: special signal names.
+
+    Returns
+    -------
+    out: Array<string>
+        List of signal names.
+
+    Examples
+    --------
+    > var out = {{alias}}()
+    e.g., [ 'datum', 'event', ... ]
+    > out = {{alias}}( 'reserved' )
+    [ 'datum', 'event', ... ]
+
+    See Also
+    --------
+

lib/node_modules/@stdlib/plot/vega/signal/names/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
+
+/**
+* Signal kind.
+*/
+type SignalKind = 'all' | 'reserved' | 'built_in' | 'special';
+
+/**
+* Returns a list of reserved signal names.
+*
+* @param kind - signal kind
+* @returns list of signal names
+*
+* @example
+* var out = signals();
+* // e.g., returns [ 'datum', 'event', ... ]
+*
+* @example
+* var list = signals( 'reserved' );
+* // e.g., returns [ 'datum', 'event', ... ]
+*/
+declare function signals( kind?: SignalKind ): Array<string>;
+
+
+// EXPORTS //
+
+export = signals;

lib/node_modules/@stdlib/plot/vega/signal/names/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 signals = require( './index' );
+
+
+// TESTS //
+
+// The function returns an array of strings when not provided any arguments...
+{
+	signals(); // $ExpectType string[]
+}
+
+// The function returns an array of strings when provided a recognized signal kind...
+{
+	signals( 'all' ); // $ExpectType string[]
+	signals( 'reserved' ); // $ExpectType string[]
+	signals( 'built_in' ); // $ExpectType string[]
+	signals( 'special' ); // $ExpectType string[]
+}
+
+// The compiler throws an error if the function is provided an invalid first argument...
+{
+	signals( 5 ); // $ExpectError
+	signals( true ); // $ExpectError
+	signals( false ); // $ExpectError
+	signals( null ); // $ExpectError
+	signals( [] ); // $ExpectError
+	signals( {} ); // $ExpectError
+	signals( ( x: number ): number => x ); // $ExpectError
+}
+
+// The compiler throws an error if the function is provided an unsupported number of arguments...
+{
+	signals( 'reserved', {} ); // $ExpectError
+}