feat: add reduce method for array/uint64

lib/node_modules/@stdlib/array/uint64/README.md

@@ -335,6 +335,44 @@ var u = arr.get( 100 );
 // returns undefined
 ```
 
+<a name="method-reduce"></a>
+
+#### Uint64Array.prototype.reduce( reducerFn\[, initialValue] )
+
+Applies a provided callback function to each element of the array, in order, passing in the return value from the calculation on the preceding element and returning the accumulated result upon completion.
+
+```javascript
+var add = require( '@stdlib/number/uint64/base/add' );
+
+var arr = new Uint64Array( [ 1, 2, 3 ] );
+
+var u = arr.reduce( add );
+// returns <Uint64>[ 6n ]
+```
+
+The reducer function is provided four arguments:
+
+-   **acc**: accumulated result.
+-   **value**: current array element.
+-   **index**: current array element index.
+-   **arr**: the array on which this method was called.
+
+By default, the function initializes the accumulated result to the first element in the array and passes the second array element as `value` during the first invocation of the provided callback. To begin accumulation from a different starting value and pass in the first array element as `value` during the first invocation of the provided callback, provide an `initialValue` argument.
+
+```javascript
+var Number = require( '@stdlib/number/ctor' );
+
+function reducer( acc, v ) {
+    acc += Number( v );
+    return acc;
+}
+
+var arr = new Uint64Array( [ 1, 2, 3 ] );
+
+var sum = arr.reduce( reducer, 2 );
+// returns 8
+```
+
 <a name="method-set"></a>
 
 #### Uint64Array.prototype.set( value\[, i] )

lib/node_modules/@stdlib/array/uint64/benchmark/benchmark.reduce.js

@@ -0,0 +1,81 @@
+/**
+* @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 isUint64 = require( '@stdlib/assert/is-uint64' );
+var add = require( '@stdlib/number/uint64/base/add' );
+var Uint64 = require( '@stdlib/number/uint64/ctor' );
+var format = require( '@stdlib/string/format' );
+var pkg = require( './../package.json' ).name;
+var Uint64Array = require( './../lib' );
+
+
+// MAIN //
+
+bench( format( '%s:reduce', pkg ), function benchmark( b ) {
+	var out;
+	var arr;
+	var i;
+
+	arr = new Uint64Array( 10 );
+
+	// Benchmark worst case scenario (i.e., every element is visited and passed to the reducer)...
+	b.tic();
+	for ( i = 0; i < b.iterations; i++ ) {
+		out = arr.reduce( add );
+		if ( typeof out !== 'object' ) {
+			b.fail( 'should return an object' );
+		}
+	}
+	b.toc();
+	if ( !isUint64( out ) ) {
+		b.fail( 'should return a 64-bit unsigned integer' );
+	}
+	b.pass( 'benchmark finished' );
+	b.end();
+});
+
+bench( format( '%s::initial_value:reduce', pkg ), function benchmark( b ) {
+	var out;
+	var arr;
+	var v;
+	var i;
+
+	arr = new Uint64Array( 10 );
+
+	v = new Uint64( 0 );
+
+	// Benchmark worst case scenario (i.e., every element is visited and passed to the reducer)...
+	b.tic();
+	for ( i = 0; i < b.iterations; i++ ) {
+		out = arr.reduce( add, v );
+		if ( typeof out !== 'object' ) {
+			b.fail( 'should return an object' );
+		}
+	}
+	b.toc();
+	if ( !isUint64( out ) ) {
+		b.fail( 'should return a 64-bit unsigned integer' );
+	}
+	b.pass( 'benchmark finished' );
+	b.end();
+});

lib/node_modules/@stdlib/array/uint64/benchmark/benchmark.reduce.length.js

@@ -0,0 +1,97 @@
+/**
+* @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 pow = require( '@stdlib/math/base/special/pow' );
+var isUint64 = require( '@stdlib/assert/is-uint64' );
+var add = require( '@stdlib/number/uint64/base/add' );
+var format = require( '@stdlib/string/format' );
+var pkg = require( './../package.json' ).name;
+var Uint64Array = require( './../lib' );
+
+
+// FUNCTIONS //
+
+/**
+* Creates a benchmark function.
+*
+* @private
+* @param {PositiveInteger} len - array length
+* @returns {Function} benchmark function
+*/
+function createBenchmark( len ) {
+	var arr = new Uint64Array( len );
+	return benchmark;
+
+	/**
+	* Benchmark function.
+	*
+	* @private
+	* @param {Benchmark} b - benchmark instance
+	*/
+	function benchmark( b ) {
+		var out;
+		var i;
+
+		// Benchmark worst case scenario (i.e., every element is visited and passed to the reducer)...
+		b.tic();
+		for ( i = 0; i < b.iterations; i++ ) {
+			out = arr.reduce( add );
+			if ( typeof out !== 'object' ) {
+				b.fail( 'should return an object' );
+			}
+		}
+		b.toc();
+		if ( !isUint64( out ) ) {
+			b.fail( 'should return a 64-bit unsigned integer' );
+		}
+		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:reduce:len=%d', pkg, len ), f );
+	}
+}
+
+main();

lib/node_modules/@stdlib/array/uint64/docs/repl.txt

@@ -299,6 +299,47 @@
     <Uint64>[ 2n ]
 
 
+{{alias}}.prototype.reduce( reducerFn[, initialValue] )
+    Applies a provided function to each element of the array, in order, passing
+    in the return value from the calculation on the preceding element and
+    returning the accumulated result upon completion.
+
+    A reducer function is provided the following arguments:
+
+    - acc: accumulated result.
+    - value: current array element.
+    - index: current array element index.
+    - arr: the array on which the method was called.
+
+    If provided an initial value, the method invokes a provided function with
+    the initial value as the first argument and the first array element as the
+    second argument.
+
+    If not provided an initial value, the method invokes a provided function
+    with the first array element as the first argument and the second array
+    element as the second argument.
+
+    Parameters
+    ----------
+    reducerFn: Function
+        Function to apply to each array element.
+
+    initialValue: any (optional)
+        Initial accumulation value.
+
+    Returns
+    -------
+    out: any
+        Accumulated result.
+
+    Examples
+    --------
+    > var arr = new {{alias}}( [ 1, 2, 3 ] )
+    <Uint64Array>[ 1n, 2n, 3n ]
+    > var u = arr.reduce( {{alias:@stdlib/number/uint64/base/add}} )
+    <Uint64>[ 6n ]
+
+
 {{alias}}.prototype.set( v[, i] )
     Sets one or more array elements.
 

lib/node_modules/@stdlib/array/uint64/docs/types/index.d.ts

@@ -28,7 +28,7 @@
 import ArrayBuffer = require( '@stdlib/array/buffer' );
 
 // Define a union type representing both iterable and non-iterable iterators:
 type Iterator = Iter | IterableIterator;
 
 // Define a type representing a value from which a 64-bit unsigned integer can be derived:
 type Uint = Uint64 | bigint | number;
@@ -36,7 +36,7 @@
 /**
 * Locale-specific configuration options.
 */
 interface LocaleOptions<T = unknown> {
 	/**
 	* Configuration property.
 	*/
@@ -118,7 +118,7 @@
 * @param arr - array on which the method was called
 * @returns boolean indicating whether an element in an array passes a test
 */
 type Predicate<U> = NullaryPredicate<U> | UnaryPredicate<U> | BinaryPredicate<U> | TernaryPredicate<U>;
 
 /**
 * Callback invoked for each element in an array.
@@ -162,7 +162,7 @@
 * @param arr - array on which the method was called
 * @returns undefined
 */
 type Callback<U> = NullaryCallback<U> | UnaryCallback<U> | BinaryCallback<U> | TernaryCallback<U>;
 
 /**
 * Callback invoked for each element in an array.
@@ -206,7 +206,7 @@
 * @param arr - array on which the method was called
 * @returns transformed value
 */
 type MapFcn<U> = NullaryMapFcn<U> | UnaryMapFcn<U> | BinaryMapFcn<U> | TernaryMapFcn<U>;
 
 /**
 * Reducer function invoked for each element in an array.
@@ -269,7 +269,7 @@
 * @param b - second value for comparison
 * @returns number indicating comparison result
 */
 type CompareFcn = ( a: Uint64, b: Uint64 ) => number;
 
 /**
 * Class for creating a 64-bit unsigned integer array.
@@ -477,6 +477,23 @@
 	*/
 	get( i: number ): Uint64 | void;
 
+	/**
+	* Applies a provided callback function to each element of the array, in order, passing in the return value from the calculation on the preceding element and returning the accumulated result upon completion.
+	*
+	* @param reducer - callback function
+	* @param initialValue - initial value
+	* @returns accumulated result
+	*
+	* @example
+	* var add = require( '@stdlib/number/uint64/base/add' );
+	*
+	* var arr = new Uint64Array( [ 1, 2, 3 ] );
+	*
+	* var u = arr.reduce( add );
+	* // returns <Uint64>[ 6n ]
+	*/
+	reduce<U = unknown>( reducer: Reducer<U>, initialValue?: U ): U;
+
 	/**
 	* Sets an array element.
 	*

lib/node_modules/@stdlib/array/uint64/lib/main.js

@@ -758,6 +758,58 @@
 	return this._length;
 });
 
+/**
+* Applies a provided callback function to each element of the array, in order, passing in the return value from the calculation on the preceding element and returning the accumulated result upon completion.
+*
+* @name reduce
+* @memberof Uint64Array.prototype
+* @type {Function}
+* @param {Function} reducer - callback function
+* @param {*} [initialValue] - initial value
+* @throws {TypeError} `this` must be a 64-bit unsigned integer array
+* @throws {TypeError} first argument must be a function
+* @throws {Error} if not provided an initial value, the array must have at least one element
+* @returns {*} accumulated result
+*
+* @example
+* var add = require( '@stdlib/number/uint64/base/add' );
+*
+* var arr = new Uint64Array( [ 1, 2, 3 ] );
+*
+* var u = arr.reduce( add );
+* // returns <Uint64>[ 6n ]
+*/
+setReadOnly( Uint64Array.prototype, 'reduce', function reduce( reducer, initialValue ) {
+	var buf;
+	var acc;
+	var len;
+	var v;
+	var i;
+	if ( !isUint64Array( this ) ) {
+		throw new TypeError( 'invalid invocation. `this` is not a 64-bit unsigned integer array.' );
+	}
+	if ( !isFunction( reducer ) ) {
+		throw new TypeError( format( 'invalid argument. First argument must be a function. Value: `%s`.', reducer ) );
+	}
+	buf = this._buffer;
+	len = this._length;
+	if ( arguments.length > 1 ) {
+		acc = initialValue;
+		i = 0;
+	} else {
+		if ( len === 0 ) {
+			throw new Error( 'invalid operation. If not provided an initial value, an array must contain at least one element.' );
+		}
+		acc = getUint64( buf, 0 );
+		i = 1;
+	}
+	for ( ; i < len; i++ ) {
+		v = getUint64( buf, i );
+		acc = reducer( acc, v, i, this );
+	}
+	return acc;
+});
+
 /**
 * Sets an array element.
 *
@@ -839,7 +891,7 @@
 		buf[ idx+indices.LOW ] = words[ 1 ];
 		return;
 	}
 	if ( isNonNegativeInteger( value ) || ( isBigInt( value ) && isNonNegativeInteger( Number( value ) ) ) ) {
 		if ( idx >= this._length ) {
 			throw new RangeError( format( 'invalid argument. Index argument is out-of-bounds. Value: `%u`.', idx ) );
 		}