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accessorGetter

Return an accessor function for retrieving an element from an array-like object supporting the get/set protocol.

Installation

npm install @stdlib/array-base-accessor-getter

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 accessorGetter = require( '@stdlib/array-base-accessor-getter' );

accessorGetter( dtype )

Returns an accessor function for retrieving an element from an array-like object supporting the get/set protocol.

var Complex64Array = require( '@stdlib/array-complex64' );
var realf = require( '@stdlib/complex-float32-real' );
var imagf = require( '@stdlib/complex-float32-imag' );

var arr = new Complex64Array( [ 1, 2, 3, 4 ] );

var get = accessorGetter( 'complex64' );
var v = get( arr, 1 );
// returns <Complex64>

var re = realf( v );
// returns 3.0

var im = imagf( v );
// returns 4.0

The returned accessor function accepts the following arguments:

• arr: input array.
• idx: element index.

Notes

• If provided an unsupported dtype, the function returns a default accessor function for accessing elements from any indexed array-like object supporting the get/set protocol; otherwise, the function returns an accessor function which should only be provided an array instance corresponding to dtype (e.g., if dtype is 'complex64', the returned accessor function should only be provided instances of Complex64Array).
• Accessor functions do not verify that provided input arrays are array instances corresponding to dtype, as doing so would introduce performance overhead. If array instances corresponding to other data types are provided to an accessor function, JavaScript runtimes will consider the function polymorphic, potentially triggering de-optimization. In order to ensure maximum performance, always ensure that an accessor function is monomorphic.
• Accessor functions do not perform bounds checking.
• Accessor functions do not verify that provided input arrays actually implement the get/set protocol.
• An array-like object supporting the get/set protocol is a data structure in which one accesses elements using explicit get and set methods (e.g., Complex64Array and Complex128Array).

Examples

var Complex128Array = require( '@stdlib/array-complex128' );
var Complex64Array = require( '@stdlib/array-complex64' );
var zeroTo = require( '@stdlib/array-base-zero-to' );
var dtype = require( '@stdlib/array-dtype' );
var accessorGetter = require( '@stdlib/array-base-accessor-getter' );

var arr = new Complex128Array( zeroTo( 10 ) );
var v = accessorGetter( dtype( arr ) )( arr, 2 );
// returns <Complex128>

console.log( v.toString() );
// => '4 + 5i'

arr = new Complex64Array( zeroTo( 10 ) );
v = accessorGetter( dtype( arr ) )( arr, 4 );
// returns <Complex64>

console.log( v.toString() );
// => '8 + 9i'

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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 © 2016-2024. The Stdlib Authors.