mout-lang-type

An extension to the mout/lang utilities for more reliable type testing

mout-lang-type is an extension to MOUT’s lang utilities. It provides two major modules: A typeOf and an isType function to be used for more reliable type checks where the included kindOf and isKind functions would fail. The difference is that those included functions always use the string description tags of objects (historically known as the [[Class]] internal slot tags) expressed in UpperCamelCase for testing, whereas these additional functions use only the limited set of built-in object tags expressed in lowerCamelCase and yield precedence to the results of the native typeof operator whenever possible:

kindOf( navigator ); // 'Navigator'
typeOf( navigator ); // 'object'

typeof []; // 'object'
typeOf( [] ); // 'array'

This extension also provides two additional modules: An instanceOf function that improves the native instanceof operator by supporting comparisons with primitive values and fixing a memory leak in legacy Internet Explorer versions; and an isComplex function that tests whether values are of complex (non-primitive) data types or not:

1 instanceof Number; // false
instanceOf( 1, Number ); // true

// No memory leaks in IE < 9 on COM objects:
instanceOf( window, Object ); // false

isComplex( 1 ); // false
isComplex( new Number ); // true

Lastly, this extension provides a bunch of replacement modules: An isPrimitive function that adds support for ES2015 symbols and finally the isFunction, isObject and isRegExp functions that internally use isType instead of isKind for their specific type checks:

isFunction( alert ); // true, even in IE7
isObject( window ); // true, same here
isPrimitive( Symbol() ); // true
isRegExp( /^regExp$/i ); // true

Getting started

Installation

Install this extension as a dependency to your project using Bower:

$ bower install --save mout-lang-type

Alternatively, it is also available using npm:

$ npm install --save mout-lang-type

Usage

You can load and use this extension as a module using the AMD or CommonJS API:

// Load the overall module:
var
  moutLangType = require('mout-lang-type');

// Use the overall module:
moutLangType.lang.instanceOf( [], Array ); // true
moutLangType.lang.typeOf( null ) === 'null'; // true


// Load all lang utilities:
var
  lang = require('mout-lang-type/lang');

// Use the lang utilities:
lang.isPrimitive( false ); // true
lang.isType( new String('foo'), 'string'); // true


// Load the individual utilities:
var
  isComplex = require('mout-lang-type/lang/isComplex'),
  isFunction = require('mout-lang-type/lang/isFunction');

// Use the individual utilities:
isComplex( new String('bar') ); // true
isFunction( Array ); // true

Keep in mind that the module’s name mout-lang-type in AMD is actually just the module’s root directory and can differ from the example above depending on your deployed scripts directory structure.

Policy

This is communist software. It is crafted with heart and soul to the best of the author’s knowledge and belief: Not for profit but to satisfy the concrete needs. Do whatever you want with it (as long as you keep the author’s copyright notice in all copies or substantial portions of it included) for free. Imagine how the world could be if others would produce and distribute their products for the same benefits and ask yourself why they’re actually not.

License

This software is licensed under MIT License.

Copyright © 2015 Christian Grete

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