feat: add accessor arrays support to blas/ext/base/gnannsumkbn

lib/node_modules/@stdlib/blas/ext/base/gnannsumkbn/README.md

@@ -119,6 +119,7 @@ var v = gnannsumkbn.ndarray( 4, x, 2, 1, out, 2, 1 );
 ## Notes
 
 -   If `N <= 0`, both functions return a sum equal to `0.0`.
+-   Both functions support array-like objects having getter and setter accessors for array element access (e.g., [`@stdlib/array/base/accessor`][@stdlib/array/base/accessor])
 
 </section>
 
@@ -190,6 +191,8 @@ console.log( out );
 
 [mdn-typed-array]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray
 
+[@stdlib/array/base/accessor]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/array/base/accessor
+
 [@neumaier:1974a]: https://doi.org/10.1002/zamm.19740540106
 
 <!-- <related-links> -->

lib/node_modules/@stdlib/blas/ext/base/gnannsumkbn/docs/types/index.d.ts

@@ -20,7 +20,17 @@
 
 /// <reference types="@stdlib/types"/>
 
-import { NumericArray } from '@stdlib/types/array';
+import { NumericArray, Collection, AccessorArrayLike } from '@stdlib/types/array';
+
+/**
+* Input array.
+*/
+type InputArray = NumericArray | Collection<number> | AccessorArrayLike<number>;
+
+/**
+* Output array.
+*/
+type OutputArray = NumericArray | Collection<number> | AccessorArrayLike<number>;
 
 /**
 * Interface describing `gnannsumkbn`.
@@ -43,7 +53,7 @@ interface Routine {
 	* var v = gnannsumkbn( x.length, x, 1, out, 1 );
 	* // returns [ 1.0, 3 ]
 	*/
-	( N: number, x: NumericArray, strideX: number, out: NumericArray, strideOut: number ): NumericArray;
+	<T extends OutputArray>( N: number, x: InputArray, strideX: number, out: T, strideOut: number ): T;
 
 	/**
 	* Computes the sum of strided array elements, ignoring `NaN` values and using an improved Kahan–Babuška algorithm and alternative indexing semantics.
@@ -64,7 +74,7 @@ interface Routine {
 	* var v = gnannsumkbn( x.length, x, 1, 0, out, 1, 0 );
 	* // returns [ 1.0, 3 ]
 	*/
-	ndarray( N: number, x: NumericArray, strideX: number, offsetX: number, out: NumericArray, strideOut: number, offsetOut: number ): NumericArray;
+	ndarray<T extends OutputArray>( N: number, x: InputArray, strideX: number, offsetX: number, out: T, strideOut: number, offsetOut: number ): T;
 }
 
 /**

lib/node_modules/@stdlib/blas/ext/base/gnannsumkbn/docs/types/test.ts

@@ -16,6 +16,7 @@
 * limitations under the License.
 */
 
+import AccessorArray = require( '@stdlib/array/base/accessor' );
 import gnannsumkbn = require( './index' );
 
 
@@ -26,7 +27,8 @@ import gnannsumkbn = require( './index' );
 	const x = new Float64Array( 10 );
 	const out = new Float64Array( 2 );
 
-	gnannsumkbn( x.length, x, 1, out, 1 ); // $ExpectType NumericArray
+	gnannsumkbn( x.length, x, 1, out, 1 ); // $ExpectType Float64Array
+	gnannsumkbn( x.length, new AccessorArray( x ), 1, new AccessorArray( out ), 1 ); // $ExpectType AccessorArray<number>
 }
 
 // The compiler throws an error if the function is provided a first argument which is not a number...
@@ -123,7 +125,8 @@ import gnannsumkbn = require( './index' );
 	const x = new Float64Array( 10 );
 	const out = new Float64Array( 2 );
 
-	gnannsumkbn.ndarray( x.length, x, 1, 0, out, 1, 0 ); // $ExpectType NumericArray
+	gnannsumkbn.ndarray( x.length, x, 1, 0, out, 1, 0 ); // $ExpectType Float64Array
+	gnannsumkbn.ndarray( x.length, new AccessorArray( x ), 1, 0, new AccessorArray( out ), 1, 0 ); // $ExpectType AccessorArray<number>
 }
 
 // The compiler throws an error if the `ndarray` method is provided a first argument which is not a number...

lib/node_modules/@stdlib/blas/ext/base/gnannsumkbn/lib/accessors.js

@@ -0,0 +1,122 @@
+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2025 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 isnan = require( '@stdlib/math/base/assert/is-nan' );
+var abs = require( '@stdlib/math/base/special/abs' );
+
+
+// MAIN //
+
+/**
+* Computes the sum of strided array elements, ignoring `NaN` values and using an improved Kahan–Babuška algorithm.
+*
+* ## Method
+*
+* -   This implementation uses an "improved Kahan–Babuška algorithm", as described by Neumaier (1974).
+*
+* ## References
+*
+* -   Neumaier, Arnold. 1974. "Rounding Error Analysis of Some Methods for Summing Finite Sums." _Zeitschrift Für Angewandte Mathematik Und Mechanik_ 54 (1): 39–51. doi:[10.1002/zamm.19740540106](https://doi.org/10.1002/zamm.19740540106).
+*
+* @private
+* @param {PositiveInteger} N - number of indexed elements
+* @param {Object} x - input array object
+* @param {Collection} x.data - input array data
+* @param {Array<Function>} x.accessors - array element accessors
+* @param {integer} strideX - stride length for `x`
+* @param {NonNegativeInteger} offsetX - starting index for `x`
+* @param {Object} out - output array object
+* @param {Collection} out.data - output array data
+* @param {Array<Function>} out.accessors - array element accessors
+* @param {integer} strideOut - stride length for `out`
+* @param {NonNegativeInteger} offsetOut - starting index for `out`
+* @returns {Object} output array object
+*
+* @example
+* var toAccessorArray = require( '@stdlib/array/base/to-accessor-array' );
+* var arraylike2object = require( '@stdlib/array/base/arraylike2object' );
+*
+* var x = toAccessorArray( [ 2.0, 1.0, 2.0, -2.0, -2.0, 2.0, 3.0, 4.0, NaN, NaN ] );
+* var out = toAccessorArray( [ 0.0, 0 ] );
+*
+* var v = gnannsumkbn( 5, arraylike2object( x ), 2, 1, arraylike2object( out ), 1, 0 );
+* // returns {...}
+*/
+function gnannsumkbn( N, x, strideX, offsetX, out, strideOut, offsetOut ) {
+	var obuf;
+	var xbuf;
+	var xget;
+	var oset;
+	var sum;
+	var ix;
+	var v;
+	var t;
+	var c;
+	var n;
+	var i;
+
+	// Cache reference to array data:
+	xbuf = x.data;
+	obuf = out.data;
+
+	// Cache reference to the element accessors:
+	xget = x.accessors[ 0 ];
+	oset = out.accessors[ 1 ];
+
+	sum = 0.0;
+	ix = offsetX;
+	if ( strideX === 0 ) {
+		v = xget( xbuf, ix );
+		if ( isnan( v ) ) {
+			oset( obuf, offsetOut, sum );
+			oset( obuf, offsetOut+strideOut, 0 );
+			return out;
+		}
+		oset( obuf, offsetOut, v * N );
+		oset( obuf, offsetOut+strideOut, N );
+		return out;
+	}
+	c = 0.0;
+	n = 0;
+	for ( i = 0; i < N; i++ ) {
+		v = xget( xbuf, ix );
+		if ( isnan( v ) === false ) {
+			t = sum + v;
+			if ( abs( sum ) >= abs( v ) ) {
+				c += (sum-t) + v;
+			} else {
+				c += (v-t) + sum;
+			}
+			sum = t;
+			n += 1;
+		}
+		ix += strideX;
+	}
+	oset( obuf, offsetOut, sum + c );
+	oset( obuf, offsetOut+strideOut, n );
+	return out;
+}
+
+
+// EXPORTS //
+
+module.exports = gnannsumkbn;

lib/node_modules/@stdlib/blas/ext/base/gnannsumkbn/lib/ndarray.js

@@ -20,8 +20,10 @@
 
 // MODULES //
 
+var arraylike2object = require( '@stdlib/array/base/arraylike2object' );
 var isnan = require( '@stdlib/math/base/assert/is-nan' );
 var abs = require( '@stdlib/math/base/special/abs' );
+var accessors = require( './accessors.js' );
 
 
 // MAIN //
@@ -56,6 +58,8 @@ var abs = require( '@stdlib/math/base/special/abs' );
 function gnannsumkbn( N, x, strideX, offsetX, out, strideOut, offsetOut ) {
 	var sum;
 	var ix;
+	var ox;
+	var oo;
 	var v;
 	var t;
 	var c;
@@ -68,6 +72,12 @@ function gnannsumkbn( N, x, strideX, offsetX, out, strideOut, offsetOut ) {
 		out[ offsetOut+strideOut ] = 0;
 		return out;
 	}
+	ox = arraylike2object( x );
+	oo = arraylike2object( out );
+	if ( ox.accessorProtocol || oo.accessorProtocol ) {
+		accessors( N, ox, strideX, offsetX, oo, strideOut, offsetOut );
+		return out;
+	}
 	ix = offsetX;
 	if ( strideX === 0 ) {
 		if ( isnan( x[ ix ] ) ) {