[TLUG]: ECMAScript ("Javascript") Version 4 - FALSE ALARM

Garrett Smith dhtmlkitchen at gmail.com
Sat Oct 27 21:29:50 PDT 2007

On 10/27/07, Dave Herman <dherman at ccs.neu.edu> wrote:
> Mark,
> The language is without doubt much larger than it was. Part of this is
> driven by a desire to provide conveniences that in ES3 people are forced
> to simulate, often at cost to both performance and clarity: classes via
> prototypes, local bindings and private members via closures, etc.

You've stated that people are forced to simulate both performance and
clarity by using closures. That is a bold statement and you have
provided no evidence to back that up. In fact, I have never heard
Douglas Crockford mention anything about performance implications or
code clarity in any of his talks, when he explains things like the
Module Pattern or Power Constructor.

Can you provide proof for this?

> part of this is driven by a need for language features with tighter
> guarantees; ES3 features such as the prototype system, global object,
> with-bindings, eval, etc. are famously anathema to abstraction,
> reasoning about code, and practical compiler optimization. So
> introducing new language features provides programmers the features they
> need and implementors greater flexibility in optimization, in order to
> keep JS competitive.

What features do programmers need?

> Finally, just to reiterate that the "it's a different language" charge
> glosses a critical aspect of the ES4 proposal, namely backwards
> compatibility. ES4 is not a new language. It is, as the overview
> describes, a significant evolution of ES3.
> Dave

Programming is a collaborative art.

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