Javascript Enum

Enum.js

/**
 * Make a bag of string constants, kind of like a Java enum.
 * e.g. var Kind = new Enum('TEXT PERSON');
 * gives you Kind.TEXT == 'TEXT', Kind.PERSON = 'PERSON'
 * 
 * Each of the constants has an isCONSTANT() function added, so you can write:
 * Kind.isTEXT(myvar) -- which has the advantage that it will create a noisy error if
 * Kind.TEXT ceased to be a valid value, or if myvar is invalid. 
 * 
 * Use-case: It's safer than using strings for constants, especially around refactoring.
 * 
 * @param values {string|string[]}
 * @constructor
 * @author Daniel
 * Ref: http://stijndewitt.wordpress.com/2014/01/26/enums-in-javascript/
 */
function Enum(values) {
	if (typeof(values)==='string') {
		values = values.split(' '); 
	}
	for(var i=0; i<values.length; i++) {
		var k = values[i];		
		this[k] = k;
		this['is'+k] = function(v) {
			if ( ! this.enum[v]) throw 'Invalid Enum value: '+v;
			return v===this.k;
		}.bind({enum:this, k:k});
	}
	// Prevent edits, if we can
	if (Object.freeze) {
		Object.freeze(this);
	}	
}