feat: add accessor array protocol for dstructs/fifo

lib/node_modules/@stdlib/dstructs/fifo/README.md

@@ -80,6 +80,59 @@ len = queue.length;
 // returns 0
 ```
 
+##### queue.every( predicate\[, thisArg] )
+
+Tests whether all elements in a queue pass a test implemented by a predicate function.
+
+```javascript
+// Test whether all elements are greater than 0:
+function predicate( v ) {
+    return v > 0;
+}
+
+var queue = fifo();
+// returns <FIFO>
+
+// Add values to the queue:
+queue.push( 1 ).push( 2 ).push( 3 );
+
+var bool = queue.every( predicate );
+// returns true
+```
+
+The `predicate` function is provided three arguments:
+
+-   **value**: current queue element.
+-   **index**: current queue element index.
+-   **q**: the queue on which the method was called.
+
+To set the function execution context, provide a `thisArg`.
+
+```javascript
+function predicate( v ) {
+    this.count += 1;
+    return v > 0;
+}
+
+// Create a queue:
+var queue = fifo();
+
+// Add values to the queue:
+queue.push( 1 ).push( 2 ).push( 3 );
+
+// Define an execution context:
+var ctx = {
+    'count': 0
+};
+
+// Test whether all elements are greater than 0:
+var bool = queue.every( predicate, ctx );
+// returns true
+
+var n = ctx.count;
+// returns 3
+```
+
 ##### queue.first()
 
 Returns the "oldest" queue value (i.e., the value which is "first-out"). If the queue is currently empty, the returned value is `undefined`.
@@ -96,6 +149,37 @@ var v = queue.first();
 // returns 'foo'
 ```
 
+##### queue.get( index )
+
+Returns a queue element located at a nonnegative integer position (index) `i`.
+
+```javascript
+var queue = fifo();
+
+// Add values to the queue:
+queue.push( 'foo' ).push( 'bar' ).push( 'baz' );
+
+// Access elements by index via the accessor protocol:
+var v = queue.get( 0 );
+// returns 'foo'
+
+v = queue.get( 1 );
+// returns 'bar'
+
+v = queue.get( 2 );
+// returns 'baz'
+```
+
+If provided an out-of-bounds index, the method returns `undefined`.
+
+```javascript
+var queue = fifo();
+
+// Out-of-bounds indices return undefined:
+var v = queue.get( 10 );
+// returns undefined
+```
+
 ##### queue.iterator()
 
 Returns an iterator for iterating over a queue. If an environment supports `Symbol.iterator`, the returned iterator is iterable.
@@ -201,6 +285,48 @@ v = queue.pop();
 // returns 'bar'
 ```
 
+##### queue.set( value, index )
+
+Sets a queue element at a specified index.
+
+```javascript
+var queue = fifo();
+// returns <FIFO>
+
+// Add values to the queue:
+queue.push( 'foo' ).push( 'bar' ).push( 'baz' );
+
+// Set elements by index:
+queue.set( 'beep', 0 );
+var v = queue.get( 0 );
+// returns 'beep'
+
+queue.set( 'boop', 1 );
+v = queue.get( 1 );
+// returns 'boop'
+```
+
+By default, the method sets queue elements starting at position (index) `i = 0`. To set elements starting elsewhere in the queue, provide an index argument `i`.
+
+```javascript
+var queue = fifo();
+// returns <FIFO>
+
+// Add values to the queue:
+queue.push( 'foo' ).push( 'bar' ).push( 'baz' );
+
+// By default, sets element at index 0:
+queue.set( 'beep' );
+var v = queue.get( 0 );
+// returns 'beep'
+
+// Set element at a specified index:
+queue.set( 'boop', 1 );
+
+v = queue.get( 1 );
+// returns 'boop'
+```
+
 ##### queue.toArray()
 
 Returns an array of queue values.

lib/node_modules/@stdlib/dstructs/fifo/benchmark/benchmark.every.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 format = require( '@stdlib/string/format' );
+var pkg = require( './../package.json' ).name;
+var FIFO = require( './../lib' );
+
+
+// MAIN //
+
+bench( format( '%s:every', pkg ), function benchmark( b ) {
+	var bool;
+	var q;
+	var i;
+
+	q = new FIFO();
+	for ( i = 1; i <= 4; i++ ) {
+		q.push( i );
+	}
+
+	b.tic();
+	for ( i = 0; i < b.iterations; i++ ) {
+		bool = q.every( function predicate( v ) {
+			return v > 0;
+		});
+		if ( typeof bool !== 'boolean' ) {
+			b.fail( 'should return a boolean' );
+		}
+	}
+	b.toc();
+	if ( typeof bool !== 'boolean' ) {
+		b.fail( 'should return a boolean' );
+	}
+	b.pass( 'benchmark finished' );
+	b.end();
+});

lib/node_modules/@stdlib/dstructs/fifo/benchmark/benchmark.every.length.js

@@ -0,0 +1,115 @@
+/*
+* @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 pow = require( '@stdlib/math/base/special/pow' );
+var format = require( '@stdlib/string/format' );
+var pkg = require( './../package.json' ).name;
+var FIFO = require( './../lib' );
+
+
+// FUNCTIONS //
+
+/**
+* Predicate function.
+*
+* @private
+* @param {boolean} value - array element
+* @param {NonNegativeInteger} idx - array element index
+* @param {FIFO} q - queue instance
+* @returns {boolean} boolean indicating whether a value passes a test
+*/
+function predicate( value ) {
+	return value > 0;
+}
+
+/**
+* Creates a benchmark function.
+*
+* @private
+* @param {PositiveInteger} len - queue length
+* @returns {Function} benchmark function
+*/
+function createBenchmark( len ) {
+	var q;
+	var i;
+
+	q = new FIFO();
+	for ( i = 0; i < len; i++ ) {
+		q.push( i );
+	}
+
+	return benchmark;
+
+	/**
+	* Benchmark function.
+	*
+	* @private
+	* @param {Benchmark} b - benchmark instance
+	*/
+	function benchmark( b ) {
+		var bool;
+		var i;
+
+		b.tic();
+		for ( i = 0; i < b.iterations; i++ ) {
+			bool = q.every( predicate );
+			if ( typeof bool !== 'boolean' ) {
+				b.fail( 'should return a boolean' );
+			}
+		}
+		b.toc();
+		if ( !isBoolean( bool ) ) {
+			b.fail( 'should return a boolean' );
+		}
+		b.pass( 'benchmark finished' );
+		b.end();
+	}
+}
+
+
+// MAIN //
+
+/**
+* Main execution sequence.
+*
+* @private
+*/
+function main() {
+	var len;
+	var min;
+	var max;
+	var f;
+	var i;
+
+	min = 1; // 10^min
+	max = 6; // 10^max
+
+	for ( i = min; i <= max; i++ ) {
+		len = pow( 10, i );
+		f = createBenchmark( len );
+		bench( format( '%s:every:len=%d', pkg, len ), f );
+	}
+}
+
+main();

lib/node_modules/@stdlib/dstructs/fifo/benchmark/benchmark.get.js

@@ -0,0 +1,54 @@
+/**
+* @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 format = require( '@stdlib/string/format' );
+var pkg = require( './../package.json' ).name;
+var FIFO = require( './../lib' );
+
+
+// MAIN //
+
+bench( format( '%s:get', pkg ), function benchmark( b ) {
+	var q;
+	var v;
+	var i;
+
+	q = new FIFO();
+	for ( i = 1; i <= 4; i++ ) {
+		q.push( i );
+	}
+
+	b.tic();
+	for ( i = 0; i < b.iterations; i++ ) {
+		v = q.get( i%4 );
+		if ( typeof v === 'undefined' ) {
+			b.fail( 'should return a value' );
+		}
+	}
+	b.toc();
+	if ( typeof v === 'undefined' ) {
+		b.fail( 'should return a value' );
+	}
+	b.pass( 'benchmark finished' );
+	b.end();
+});