@jo … ActionScript 3 is closer to Java than ES4 and in a first comparasion it seems that the only similar thing is strict type notation (x:Point) and classes structure.
If I’m not wrong AS3 hasn’t lambda like functions
function(x:int, y:int):int x * y
it hasn’t get / set shortcuts and meta declarations and I never read about intrinsic or for each in and array assignment (for i* i in … if() or [a,b] = [b,a]).
It seems that ES4 take advantages of many different languages such Python, Java, AS3 or Neko and ES3 itself … it seems to be a powerful and wonderful language using both old and new style code.

On Crockford , cited by @Steve: It’s ironic that Doug invoked reason (“harder to reason about”), since reason => logic => proof => type system, and the supposedly simpler, smaller dynamic core of JS1/ES3 lacks not only types in the language, but basic things like immutable name bindings. You can override Object or Array (hazards to JSON decoders), or blow away someone else’s properties. This is good in prototype objects for AOP, maybe (I’m to blame for it, but I don’t defend it). For global bindings it’s a fatal flaw when trying to reason about type soundness and security properties such as integrity. ES4 is bigger in many ways (it has been eight years since ES3) but it is actually easier to reason about ES4 code than ES3 code, not only for humans but (more important, because reasoning should be automated where it can be, and you shouldn’t trust human-only security audits) for type checkers and security analyzers.

/be

var it = Iterator(myObject);

while (it.hasNext()) {
print(it.next());
}

try{
… iterate …
}
catch(e:StopIteration){
… continue ….
}
catch(e:Error){
… break execution …
}
finally {
… doStuff if You need them …
}

hasNext is a “magic” method You should implement by yourself using intrinsic or caching next result in your iterator.

The best things I can see is that quite everything is customizable, starting with operators (+, -, === … others)

Isn’t cool? As I said, I can’t wait 2009 to use ES4 …. please run! :D


class C {
function get x() { ... }
function set x(value) { ... }
}



class D {
meta function get(name) { ... }
meta function set(name, value) { ... }
}


@Joeri

I’m not aware of any major compatibility issues between browsers in the base language.

just think about let, yeld, [a,b] = [b,a], for each in and every other amazing stuff We have only in Geko and We can’t use/write in a cross browser way.
Just think about every library We know, each one has, for example, its own implementation of Array.prototype.forEach … just think about a “less typeless” code and its performances … and so on.

What I mean is that in my opinion there’s any relation between JS browser security problems (please don’t forget that JS isn’t used only with browsers) and natural program language (impressive) evolution like that.
If security should block sofware evolution so We should still use Win 95 and Sco … isn’t right? :-)

A lot of game developers use Lua as the scripting language for their games. The Lua runtime is very compact and fast, and easy to integrate with C code.

We’re not likely to see Lua in the browser any time soon, though…