Refutable destructuring

Brendan Eich brendan at
Fri Aug 9 20:52:35 PDT 2013

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), but you still swapped refutable and 
irrefutable :-P.

> 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 ;-).


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