@stdlib/utils-define-memoized-read-only-property N

Memoized Read-Only

Define a memoized read-only object property.

Installation

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

Usage

var setMemoizedReadOnly = require( '@stdlib/utils-define-memoized-read-only-property' );

setMemoizedReadOnly( obj, prop, fcn )

Defines a memoized read-only object property.

var obj = {};

function foo() {
    return 'bar';
}

setMemoizedReadOnly( obj, 'foo', foo );

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

The last argument should be a synchronous function whose return value will be memoized and set as the property value.

Notes

A read-only property is enumerable and non-configurable; however, until deferred evaluation, an object property is configurable.

Examples

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

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

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.