Comments on: JavaScript New Features (EcmaScript 5) http://markcaudill.com/index.php/2009/04/javascript-new-features-ecma5/ All about me Tue, 07 Sep 2010 21:22:44 +0000 http://wordpress.org/?v=2.5.1 By: Mark Caudill http://markcaudill.com/index.php/2009/04/javascript-new-features-ecma5/#comment-71 Mark Caudill Sat, 18 Apr 2009 13:04:09 +0000 http://markcaudill.com/?p=6#comment-71 Brendan: Thanks for the correction! I did look at the spec but I overlooked 10.5 CreateArgumentsObject #5, I only saw the argument getting the Arguments class. Alo, harmony looks exciting as well, but the fact that ES5 is already making motions to implementation really make the immediate future promising. I can see a year from now us having a "ES5-rollup" library (in Javascript) that attempts compatibility when using "ES3." Great things to come no matter what though. Brendan: Thanks for the correction! I did look at the spec but I overlooked 10.5 CreateArgumentsObject #5, I only saw the argument getting the Arguments class.

Alo, harmony looks exciting as well, but the fact that ES5 is already making motions to implementation really make the immediate future promising. I can see a year from now us having a “ES5-rollup” library (in Javascript) that attempts compatibility when using “ES3.” Great things to come no matter what though.

]]> By: Brendan Eich http://markcaudill.com/index.php/2009/04/javascript-new-features-ecma5/#comment-70 Brendan Eich Sat, 18 Apr 2009 05:05:29 +0000 http://markcaudill.com/?p=6#comment-70 Konrad@5:55pm - ES5 does make arguments have Array.prototype in its prototype chain, a change from ES1-3. So you can say arguments.slice(0,2), e.g., and not the overlong Array.prototype.slice.call(arguments,0,2). Coming in ES Harmony: rest parameters, as drafted for ES4: function foo(fst, snd, ...rest) { /* here rest is a true Array instance */ }. To match, the "spread" operator: given an Array arr, you can spread it out so its elements are passed as positional parameters to a function foo, via foo(...arr). With rest and the spread operator, one can compose new and apply without a hardcoded newApply method, and the need for arguments goes away. /be Konrad@5:55pm - ES5 does make arguments have Array.prototype in its prototype chain, a change from ES1-3. So you can say arguments.slice(0,2), e.g., and not the overlong Array.prototype.slice.call(arguments,0,2).

Coming in ES Harmony: rest parameters, as drafted for ES4: function foo(fst, snd, …rest) { /* here rest is a true Array instance */ }. To match, the “spread” operator: given an Array arr, you can spread it out so its elements are passed as positional parameters to a function foo, via foo(…arr). With rest and the spread operator, one can compose new and apply without a hardcoded newApply method, and the need for arguments goes away.

/be

]]> By: Mark Caudill, a ninja in waiting » JavaScript New Features … http://markcaudill.com/index.php/2009/04/javascript-new-features-ecma5/#comment-68 Mark Caudill, a ninja in waiting » JavaScript New Features … Wed, 15 Apr 2009 07:01:40 +0000 http://markcaudill.com/?p=6#comment-68 [...] Originally posted here: Mark Caudill, a ninja in waiting » JavaScript New Features … [...] [...] Originally posted here: Mark Caudill, a ninja in waiting » JavaScript New Features … [...]

]]> By: JavaScript is getting a facelift. http://markcaudill.com/index.php/2009/04/javascript-new-features-ecma5/#comment-67 JavaScript is getting a facelift. Wed, 15 Apr 2009 00:49:28 +0000 http://markcaudill.com/?p=6#comment-67 [...] Or more like an upgrade. Mark Cuadill has more to say about it. [...] [...] Or more like an upgrade. Mark Cuadill has more to say about it. [...]

]]> By: Konrad Zielinski http://markcaudill.com/index.php/2009/04/javascript-new-features-ecma5/#comment-66 Konrad Zielinski Tue, 14 Apr 2009 23:52:43 +0000 http://markcaudill.com/?p=6#comment-66 arguments.callee is usefull. but arguments could have still just being an Array with an extra property rather then a completely unrelated object which just happens to behave the same, some of the time (you still have arguments.length). Ditto for Strings. The other question being, once the draft gets accepted how long will it be before we see support in all of the wonderful new JavaScript engines. arguments.callee is usefull. but arguments could have still just being an Array with an extra property rather then a completely unrelated object which just happens to behave the same, some of the time (you still have arguments.length). Ditto for Strings.

The other question being, once the draft gets accepted how long will it be before we see support in all of the wonderful new JavaScript engines.

]]> By: Mark Caudill http://markcaudill.com/index.php/2009/04/javascript-new-features-ecma5/#comment-65 Mark Caudill Tue, 14 Apr 2009 23:22:30 +0000 http://markcaudill.com/?p=6#comment-65 Konrad: Arguments is a special object still, but... *Edit: See Bredan's post below, he explains that arguments now uses the Array.prototype but is still a "special class" of an object* Konrad: Arguments is a special object still, but…

*Edit: See Bredan’s post below, he explains that arguments now uses the Array.prototype but is still a “special class” of an object*

]]> By: Konrad Zielinski http://markcaudill.com/index.php/2009/04/javascript-new-features-ecma5/#comment-64 Konrad Zielinski Tue, 14 Apr 2009 22:55:42 +0000 http://markcaudill.com/?p=6#comment-64 I always found it strange that 'arguments' is an object and not an Array. having all of these new Array methods is really neat, but can be rather furstrating if you can't use them on the arguments your function just received. So has this been changed too? I always found it strange that ‘arguments’ is an object and not an Array. having all of these new Array methods is really neat, but can be rather furstrating if you can’t use them on the arguments your function just received.

So has this been changed too?

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