Refutable destructuring

Rick Waldron waldron.rick at
Sat Aug 10 13:23:15 PDT 2013

On Fri, Aug 9, 2013 at 11:52 PM, Brendan Eich <brendan at> wrote:

> Rick Waldron wrote:
>> My argument was specifically about the current meaning of the ascii
>> exclamation "!" and that assigning it an additional context-based meaning
>> that's quite the opposite of the current unary operator meaning,
> Ok, and I'm with you (recall Mark M. wants ! as restricted-production
> binary operator for promises),

Yep, and I've also expressed my concern with that use as well, from yet a
different perspective: (note
that my point there has no basis in existing JS operator semantics and was
completely subjective).

> but you still swapped refutable and irrefutable :-P.

Only for the sake of making the grok-ability argument! ;)

>  isn't a proposal that I would support. This is stated with no regard for
>> previous refutable matching proposals.
> Right, but remember: the kind of destructuring that imputes undefined for
> missing property is irrefutable. Can't refute so can't mismatch so can't
> fall thru to later match-case. That's all I wanted to get across ;-).

Of course and I should've addressed that originally so that my points
would've been clearer—apologies for the noise caused by not doing so.


> /be
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <>

More information about the es-discuss mailing list