feat: add accessor array support to blas/base/gdot

PR-URL: #5878
Closes: stdlib-js/metr-issue-tracker#23
Co-authored-by: Athan Reines <[email protected]>
Reviewed-by: Athan Reines <[email protected]> 
Signed-off-by: Athan Reines <[email protected]>

Author: headlessNode

lib/node_modules/@stdlib/blas/base/gdot/README.md

@@ -137,6 +137,7 @@ var z = gdot.ndarray( 3, x, 2, 1, y, -1, y.length-1 );
 
 -   If `N <= 0` both functions return `0.0`.
 -   `gdot()` corresponds to the [BLAS][blas] level 1 function [`ddot`][ddot] with the exception that this implementation works with any array type, not just Float64Arrays. Depending on the environment, the typed versions ([`ddot`][@stdlib/blas/base/ddot], [`sdot`][@stdlib/blas/base/sdot], etc.) are likely to be significantly more performant.
+-   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>
 
@@ -199,6 +200,8 @@ 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
+
 [@stdlib/blas/base/ddot]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/blas/base/ddot
 
 [@stdlib/blas/base/sdot]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/blas/base/sdot

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

@@ -20,7 +20,12 @@
 
 /// <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>;
 
 /**
 * Interface describing `gdot`.
@@ -43,7 +48,7 @@ interface Routine {
 	* var z = gdot( x.length, x, 1, y, 1 );
 	* // returns -5.0
 	*/
-	( N: number, x: NumericArray, strideX: number, y: NumericArray, strideY: number ): number;
+	( N: number, x: InputArray, strideX: number, y: InputArray, strideY: number ): number;
 
 	/**
 	* Computes the dot product of two vectors using alternative indexing semantics.
@@ -64,7 +69,7 @@ interface Routine {
 	* var z = gdot.ndarray( x.length, x, 1, 0, y, 1, 0 );
 	* // returns -5.0
 	*/
-	ndarray( N: number, x: NumericArray, strideX: number, offsetX: number, y: NumericArray, strideY: number, offsetY: number ): number;
+	ndarray( N: number, x: InputArray, strideX: number, offsetX: number, y: InputArray, strideY: number, offsetY: number ): number;
 }
 
 /**

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

@@ -16,6 +16,7 @@
 * limitations under the License.
 */
 
+import AccessorArray = require( '@stdlib/array/base/accessor' );
 import gdot = require( './index' );
 
 
@@ -27,6 +28,7 @@ import gdot = require( './index' );
 	const y = new Float64Array( 10 );
 
 	gdot( x.length, x, 1, y, 1 ); // $ExpectType number
+	gdot( x.length, new AccessorArray( x ), 1, y, 1 ); // $ExpectType number
 }
 
 // The compiler throws an error if the function is provided a first argument which is not a number...
@@ -124,6 +126,7 @@ import gdot = require( './index' );
 	const y = new Float64Array( 10 );
 
 	gdot.ndarray( x.length, x, 1, 0, y, 1, 0 ); // $ExpectType number
+	gdot.ndarray( x.length, new AccessorArray( x ), 1, 0, y, 1, 0 ); // $ExpectType 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/base/gdot/lib/accessors.js

@@ -0,0 +1,108 @@
+/**
+* @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';
+
+// VARIABLES //
+
+var M = 5;
+
+
+// MAIN //
+
+/**
+* Computes the dot product of `x` and `y`.
+*
+* @private
+* @param {integer} N - number of indexed elements
+* @param {Object} x - first input array object
+* @param {Collection} x.data - first input array data
+* @param {Array<Function>} x.accessors - first array element accessors
+* @param {integer} strideX - `x` stride length
+* @param {NonNegativeInteger} offsetX - starting index for `x`
+* @param {Object} y - second input array object
+* @param {Collection} y.data - second input array data
+* @param {Array<Function>} y.accessors - second array element accessors
+* @param {integer} strideY - `y` stride length
+* @param {NonNegativeInteger} offsetY - starting index for `y`
+* @returns {number} dot product
+*
+* @example
+* var toAccessorArray = require( '@stdlib/array/base/to-accessor-array' );
+* var arraylike2object = require( '@stdlib/array/base/arraylike2object' );
+*
+* var x = [ 4.0, 2.0, -3.0, 5.0, -1.0 ];
+* var y = [ 2.0, 6.0, -1.0, -4.0, 8.0 ];
+*
+* var z = gdot( x.length, arraylike2object( toAccessorArray( x ) ), 1, 0, arraylike2object( toAccessorArray( y ) ), 1, 0 );
+* // returns -5.0
+*/
+function gdot( N, x, strideX, offsetX, y, strideY, offsetY ) {
+	var xbuf;
+	var ybuf;
+	var xget;
+	var yget;
+	var dot;
+	var ix;
+	var iy;
+	var m;
+	var i;
+
+	xbuf = x.data;
+	ybuf = y.data;
+	xget = x.accessors[ 0 ];
+	yget = y.accessors[ 0 ];
+
+	dot = 0.0;
+	ix = offsetX;
+	iy = offsetY;
+
+	// Use unrolled loops if both strides are equal to `1`...
+	if ( strideX === 1 && strideY === 1 ) {
+		m = N % M;
+
+		// If we have a remainder, run a clean-up loop...
+		if ( m > 0 ) {
+			for ( i = 0; i < m; i++ ) {
+				dot += xget( xbuf, ix ) * yget( ybuf, iy );
+				ix += 1;
+				iy += 1;
+			}
+		}
+		if ( N < M ) {
+			return dot;
+		}
+		for ( i = m; i < N; i += M ) {
+			dot += ( xget( xbuf, ix ) * yget( ybuf, iy ) ) + ( xget( xbuf, ix+1 ) * yget( ybuf, iy+1 ) ) + ( xget( xbuf, ix+2 ) * yget( ybuf, iy+2 ) ) + ( xget( xbuf, ix+3 ) * yget( ybuf, iy+3 ) ) + ( xget( xbuf, ix+4 ) * yget( ybuf, iy+4 ) ); // eslint-disable-line max-len
+			ix += M;
+			iy += M;
+		}
+		return dot;
+	}
+	for ( i = 0; i < N; i++ ) {
+		dot += xget( xbuf, ix ) * yget( ybuf, iy );
+		ix += strideX;
+		iy += strideY;
+	}
+	return dot;
+}
+
+
+// EXPORTS //
+
+module.exports = gdot;

lib/node_modules/@stdlib/blas/base/gdot/lib/main.js

@@ -18,9 +18,10 @@
 
 'use strict';
 
-// VARIABLES //
+// MODULES //
 
-var M = 5;
+var stride2offset = require( '@stdlib/strided/base/stride2offset' );
+var ndarray = require( './ndarray.js' );
 
 
 // MAIN //
@@ -43,50 +44,7 @@ var M = 5;
 * // returns -5.0
 */
 function gdot( N, x, strideX, y, strideY ) {
-	var dot;
-	var ix;
-	var iy;
-	var m;
-	var i;
-
-	dot = 0.0;
-	if ( N <= 0 ) {
-		return dot;
-	}
-	// Use unrolled loops if both strides are equal to `1`...
-	if ( strideX === 1 && strideY === 1 ) {
-		m = N % M;
-
-		// If we have a remainder, run a clean-up loop...
-		if ( m > 0 ) {
-			for ( i = 0; i < m; i++ ) {
-				dot += x[ i ] * y[ i ];
-			}
-		}
-		if ( N < M ) {
-			return dot;
-		}
-		for ( i = m; i < N; i += M ) {
-			dot += ( x[i]*y[i] ) + ( x[i+1]*y[i+1] ) + ( x[i+2]*y[i+2] ) + ( x[i+3]*y[i+3] ) + ( x[i+4]*y[i+4] ); // eslint-disable-line max-len
-		}
-		return dot;
-	}
-	if ( strideX < 0 ) {
-		ix = ( 1-N ) * strideX;
-	} else {
-		ix = 0;
-	}
-	if ( strideY < 0 ) {
-		iy = ( 1-N ) * strideY;
-	} else {
-		iy = 0;
-	}
-	for ( i = 0; i < N; i++ ) {
-		dot += ( x[ ix ] * y[ iy ] );
-		ix += strideX;
-		iy += strideY;
-	}
-	return dot;
+	return ndarray( N, x, strideX, stride2offset( N, strideX ), y, strideY, stride2offset( N, strideY ) ); // eslint-disable-line max-len
 }
 
 

lib/node_modules/@stdlib/blas/base/gdot/lib/ndarray.js

@@ -18,6 +18,12 @@
 
 'use strict';
 
+// MODULES //
+
+var arraylike2object = require( '@stdlib/array/base/arraylike2object' );
+var accessors = require( './accessors.js' );
+
+
 // VARIABLES //
 
 var M = 5;
@@ -48,13 +54,20 @@ function gdot( N, x, strideX, offsetX, y, strideY, offsetY ) {
 	var dot;
 	var ix;
 	var iy;
+	var ox;
+	var oy;
 	var m;
 	var i;
 
 	dot = 0.0;
 	if ( N <= 0 ) {
 		return dot;
 	}
+	ox = arraylike2object( x );
+	oy = arraylike2object( y );
+	if ( ox.accessorProtocol || oy.accessorProtocol ) {
+		return accessors( N, ox, strideX, offsetX, oy, strideY, offsetY );
+	}
 	ix = offsetX;
 	iy = offsetY;