Existential operator (was: ||= is much needed?)

[Brendan Eich]

Brendan Eich wrote:
> This is infelicitous compared to putting ? first because it separates 
> the ? from the maybe-nully left operand too much, and looks ugly (to 
> Spanish readers it looks even more wrong).

It's also a loss to deviate from CS, but we can't do ?( so we're half 
(or 1/14th by the CoffeeScript usage-grep stats) deviated.

And putting ? after ( is future-hostile to any ?-unary-prefix operator, 
but I believe the only viable such prospective syntax is in patterns 
(destructuring on steroids), so not after a ( that starts an argument list.

/be