Define Memoized Property

Define a memoized object property.

Installation

npm install @stdlib/utils-define-memoized-property

Usage

var defineMemoizedProperty = require( '@stdlib/utils-define-memoized-property' );

defineMemoizedProperty( obj, prop, descriptor )

Defines a memoized object property.

var obj = {};

function foo() {
    return 'bar';
}

defineMemoizedProperty( obj, 'foo', {
    'configurable': false,
    'enumerable': true,
    'writable': false,
    'value': foo
});

var v = obj.foo;
// returns 'bar'

A property descriptor has the following required properties:

• value: synchronous function whose return value will be memoized and set as the property value.

A property descriptor has the following optional properties:

• configurable: boolean indicating if property descriptor can be changed and if the property can be deleted from the provided object. Default: false.
• enumerable: boolean indicating if the property shows up when enumerating object properties. Default: false.
• writable: boolean indicating if the value associated with the property can be changed with an assignment operator. Default: false.

Notes

• Until deferred evaluation, an object property is configurable.

Examples

var fibonacci = require( '@stdlib/math-base-special-fibonacci' );
var defineMemoizedProperty = require( '@stdlib/utils-define-memoized-property' );

function Foo() {
    var self;
    if ( !(this instanceof Foo) ) {
        return new Foo();
    }
    self = this;
    this.count = 0;
    defineMemoizedProperty( this, 'fibo', {
        'value': fibo
    });
    return this;

    function fibo() {
        self.count += 1;
        return fibonacci( 73 );
    }
}

var foo = new Foo();

var i;
for ( i = 0; i < 10; i++ ) {
    console.log( 'F: %d. Count: %d.', foo.fibo, foo.count );
}

See Also

• @stdlib/utils-define-memoized-read-only-property: define a memoized read-only object property.
• @stdlib/utils-define-property: define (or modify) an object property.

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

License

See LICENSE.

Copyright

Copyright © 2016-2024. The Stdlib Authors.