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dispatch

Dispatch to a native add-on applying a binary function to two input strided arrays.

Installation

npm install @stdlib/strided-base-binary-addon-dispatch

Alternatively,

• To load the package in a website via a script tag without installation and bundlers, use the ES Module available on the esm branch (see README).
• If you are using Deno, visit the deno branch (see README for usage intructions).
• For use in Observable, or in browser/node environments, use the Universal Module Definition (UMD) build available on the umd branch (see README).

The branches.md file summarizes the available branches and displays a diagram illustrating their relationships.

To view installation and usage instructions specific to each branch build, be sure to explicitly navigate to the respective README files on each branch, as linked to above.

Usage

var dispatch = require( '@stdlib/strided-base-binary-addon-dispatch' );

dispatch( addon, fallback )

Returns a function which dispatches to a native add-on applying a binary function to two input strided arrays.

function addon( N, dtypeX, x, strideX, dtypeY, y, strideY, dtypeZ, z, strideZ ) {
    // Call into native add-on...
}

function fallback( N, dtypeX, x, strideX, dtypeY, y, strideY, dtypeZ, z, strideZ ) {
    // Fallback JavaScript implementation...
}

// Create a dispatch function:
var f = dispatch( addon, fallback );

// ...

// Invoke the dispatch function with strided array arguments:
f( 2, 'generic', [ 1, 2 ], 1, 'generic', [ 3, 4 ], 1, 'generic', [ 0, 0 ], 1 );

The returned function has the following signature:

f( N, dtypeX, x, strideX, dtypeY, y, strideY, dtypeZ, z, strideZ )

where

• N: number of indexed elements.
• dtypeX: x data type.
• x: input array.
• strideX: x stride length.
• dtypeY: y data type.
• y: input array.
• strideY: y stride length.
• dtypeZ: z data type.
• z: output array.
• strideZ: z stride length.

The addon function should have the following signature:

f( N, dtypeX, x, strideX, dtypeY, y, strideY, dtypeZ, z, strideZ )

where

• N: number of indexed elements.
• dtypeX: x data type (enumeration constant).
• x: input array.
• strideX: x stride length.
• dtypeY: y data type (enumeration constant).
• y: input array.
• strideY: y stride length.
• dtypeZ: z data type (enumeration constant).
• z: output array.
• strideZ: z stride length.

The fallback function should have the following signature:

f( N, dtypeX, x, strideX, dtypeY, y, strideY, dtypeZ, z, strideZ )

where

• N: number of indexed elements.
• dtypeX: x data type.
• x: input array.
• strideX: x stride length.
• dtypeY: y data type.
• y: input array.
• strideY: y stride length.
• dtypeZ: z data type.
• z: output array.
• strideZ: z stride length.

dispatch.ndarray( addon, fallback )

Returns a function which dispatches to a native add-on applying a binary function to two input strided arrays using alternative indexing semantics.

function addon( N, dtypeX, x, strideX, dtypeY, y, strideY, dtypeZ, z, strideZ ) {
    // Call into native add-on...
}

function fallback( N, dtypeX, x, strideX, offsetX, dtypeY, y, strideY, offsetY, dtypeZ, z, strideZ, offsetZ ) {
    // Fallback JavaScript implementation...
}

// Create a dispatch function:
var f = dispatch.ndarray( addon, fallback );

// ...

// Invoke the dispatch function with strided array arguments:
f( 2, 'generic', [ 1, 2 ], 1, 0, 'generic', [ 3, 4 ], 1, 0, 'generic', [ 0, 0 ], 1, 0 );

The returned function has the following signature:

f( N, dtypeX, x, strideX, offsetX, dtypeY, y, strideY, offsetY, dtypeZ, z, strideZ, offsetZ )

where

• N: number of indexed elements.
• dtypeX: x data type.
• x: input array.
• strideX: x stride length.
• offsetX: starting x index.
• dtypeY: y data type.
• y: input array.
• strideY: y stride length.
• offsetY: starting y index.
• dtypeZ: z data type.
• z: output array.
• strideZ: z stride length.
• offsetZ: starting z index.

The addon function should have the following signature:

f( N, dtypeX, x, strideX, dtypeY, y, strideY, dtypeZ, z, strideZ )

where

• N: number of indexed elements.
• dtypeX: x data type (enumeration constant).
• x: input array.
• strideX: x stride length.
• dtypeY: y data type (enumeration constant).
• y: input array.
• strideY: y stride length.
• dtypeZ: z data type (enumeration constant).
• z: output array.
• strideZ: z stride length.

The fallback function should have the following signature:

f( N, dtypeX, x, strideX, offsetX, dtypeY, y, strideY, offsetY, dtypeZ, z, strideZ, offsetZ )

where

• N: number of indexed elements.
• dtypeX: x data type.
• x: input array.
• strideX: x stride length.
• offsetX: starting x index.
• dtypeY: y data type.
• y: input array.
• strideY: y stride length.
• offsetY: starting y index.
• dtypeZ: z data type.
• z: output array.
• strideZ: z stride length.
• offsetZ: starting z index.

Notes

• To determine whether to dispatch to the addon function, the returned dispatch function checks whether the provided arrays are typed arrays. If the provided arrays are typed arrays, the dispatch function invokes the addon function; otherwise, the dispatch function invokes the fallback function.

Examples

var Float64Array = require( '@stdlib/array-float64' );
var dispatch = require( '@stdlib/strided-base-binary-addon-dispatch' );

function addon( N, dtypeX, x, strideX, dtypeY, y, strideY, dtypeZ, z, strideZ ) {
    console.log( x );
    // => <Float64Array>[ 3, 4 ]

    console.log( y );
    // => <Float64Array>[ 7, 8 ]

    console.log( z );
    // => <Float64Array>[ 0, 0 ]
}

function fallback( N, dtypeX, x, strideX, offsetX, dtypeY, y, strideY, offsetY, dtypeZ, z, strideZ, offsetZ ) {
    console.log( x );
    // => [ 1, 2, 3, 4 ]

    console.log( y );
    // => [ 5, 6, 7, 8 ]

    console.log( z );
    // => [ 0, 0, 0, 0 ]
}

// Create a dispatch function:
var f = dispatch.ndarray( addon, fallback );

// Create strided arrays:
var x = new Float64Array( [ 1, 2, 3, 4 ] );
var y = new Float64Array( [ 5, 6, 7, 8 ] );
var z = new Float64Array( [ 0, 0, 0, 0 ] );

// Dispatch to the add-on function:
f( 2, 'float64', x, 1, 2, 'float64', y, 1, 2, 'float64', z, 1, 2 );

// Define new strided arrays:
x = [ 1, 2, 3, 4 ];
y = [ 5, 6, 7, 8 ];
z = [ 0, 0, 0, 0 ];

// Dispatch to the fallback function:
f( 2, 'generic', x, 1, 2, 'generic', y, 1, 2, 'generic', z, 1, 2 );

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Notice

This package is part of stdlib, a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.

For more information on the project, filing bug reports and feature requests, and guidance on how to develop stdlib, see the main project repository.

Community

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License

See LICENSE.

Copyright

Copyright © 2016-2025. The Stdlib Authors.