"Harmony is a super-set of ES5 strict"
allen at wirfs-brock.com
Fri Feb 25 15:17:32 PST 2011
On Feb 25, 2011, at 1:12 PM, Boris Zbarsky wrote:
> On 2/25/11 4:08 PM, David Bruant wrote:
>> I would tend to be more in favor of disallowing Harmony features in
>> non-strict code (without explicit "use strict" directive) to avoid
>> surprises (I'm nuancing below).
> I was under the impression that Harmony features would only be allowed for scripts that opt in to them (via the type or language of the <script> tag or whatnot). Does that alleviate this concern?
The other subtlety is that this only applies only to the actual language features not to the behavior of objects. Any new property added to the existing built-in objects will most likely be visible to non-harmony code and function and objects defined using harmony features (including Proxy) can be passed to and accessed by non-harmony code. This is comparable to what happens in ES5 where non-strict code may call a strict mode function.
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