xperiments

// => http://stackoverflow.com/questions/17392349/how-can-i-check-if-element-is-an-instanceof-u

function OfType<T, U>(list: T[], arg: Function) : U[]
{
    var result: U[] = [];

    list.forEach(e => {
        // extract the name of the class
        // used to match primitive types
        var typeName = /function\s*([^(]*)/i.exec(arg+"")[1].toLocaleLowerCase();

xperiments

The "trick" is to binary AND a value with 1.
Any odd number must have the first bit set to 1.

So

var foo = 7;

if( foo & 1 ) { // true }

Using a bitwise AND has a better performance in almost all platforms / browsers.

xperiments

var isOpera = !!window.opera || navigator.userAgent.indexOf(' OPR/') >= 0;
    // Opera 8.0+ (UA detection to detect Blink/v8-powered Opera)
var isFirefox = typeof InstallTrigger !== 'undefined';   // Firefox 1.0+
var isSafari = Object.prototype.toString.call(window.HTMLElement).indexOf('Constructor') > 0;
    // At least Safari 3+: "[object HTMLElementConstructor]"
var isChrome = !!window.chrome && !isOpera;              // Chrome 1+
var isIE = /*@cc_on!@*/false;                            // At least IE6

xperiments

//http://stackoverflow.com/questions/15877362/declare-and-initialize-a-dictionary-in-typescript

interface IDictionary {
    add(key: string, value: any): void;
    remove(key: string): void;
    containsKey(key: string): bool;
    keys(): string[];
    values(): any[];
}

xperiments

module x
{
	export class Singleton
	{
	    private static _instance : Singleton;
		constructor( singletonEnforcer:()=>void )
		{
			if( singletonEnforcer !== SingletonEnforcer )
			{
				throw new Error("Error: Instantiation failed: Use Singleton.getInstance() instead of new.");

xperiments

http://stackoverflow.com/questions/13407036/how-does-typescript-interfaces-with-construct-signatures-work

Construct signatures in interfaces are not implementable in classes; they're only for defining existing JS APIs that define a 'new'-able function. Here's an example involving interfaces new signatures that does work:

interface ComesFromString {
    name: string;
}

interface StringConstructable {
    new(n: string): ComesFromString;