I find the new suggestions hard to make sense of and the current approach quite
elegant:
```
Foo[[Construct]](arg) ::=
1. let obj = Foo[@@create]()
2. Foo.call(obj, arg)
```
To me, it seems that this is how things should work internally, because that’s
what’s actually going on. Is there no other way to fix the following two
problems? For example: to fix #2, couldn’t we somehow prevent direct
invocations? I also don’t fully understand what #1 means.
1. If instances aren't sufficiently initialized by @@create, then instance
objects could leak (e.g. via a nefarious decoupling between the @@create
allocation process and the constructor-function initialization process)
2. @@create could be called directly
Observation about the new approach:: could the `if (new^) ...` check be turned
into a method?
Axel
On 11 Sep 2014, at 18:35 , Allen Wirfs-Brock <al...@wirfs-brock.com> wrote:
> At the last TC39 meeting (
> https://github.com/rwaldron/tc39-notes/blob/master/es6/2014-07/jul-30.md#44-instantiation-reform-review-create-design-rationale-and-possible-alternatives
> and
> https://github.com/rwaldron/tc39-notes/blob/master/es6/2014-07/jul-31.md#44-follow-up-instantiation-reform-create
> ) we agreed to a general direction to try for a new object instantiation
> design to replace @@create.
>
> Since then I have gotten feedback and had design discussions with a number of
> individuals. This has lead to a number of refinements of the core design and
> one remaining point where there are strong contrary positions. The point of
> contention is about whether or not a subclass construction ever implicitly
> calls its superclass constructor.
>
> https://gist.github.com/allenwb/291035fbf910eab8e9a6 summaries the main
> syntactic changes since the meeting and provides rationales them. These
> features are common to both alternates. this is a good place to start,
> after reading the meeting notes.
>
> I have prepared two longer Gists that outline the two alternatives designs,
> presents design rationales, and provides usage examples for a number of
> likely use cases. Note that there is more commonalities then differences
> among the two alternatives. the syntactic choices and semantics of
> [[Construct]] are the same for both.
>
> These two Gist have parallel construction for easy comparison. I suggest
> approaching this is by first readying through one of the Gists and then doing
> a side by side read through of the alternative to see the differences in the
> designs and usage.
>
> https://gist.github.com/allenwb/5160d109e33db8253b62 with implicit super
> construct if no local allocation
> https://gist.github.com/allenwb/53927e46b31564168a1d explicit super construct
> required if no local allocation
>
> I appreciate it if major constructive feedback on any of these documents were
> made via Gist comments.
>
> Allen
> _______________________________________________
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--
Dr. Axel Rauschmayer
a...@rauschma.de
rauschma.de
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