typeof symbol (Was: Sept 19 TC39 Meeting Notes)

Brendan Eich brendan at mozilla.com
Mon Oct 1 12:42:17 PDT 2012

Andreas Rossberg wrote:
> On 30 September 2012 00:08, Brendan Eich<brendan at mozilla.org>  wrote:
>> I think this is too philosophical a discussion to result in a strong reason 
>> to risk "symbol". Just my gut-check. Other TC39ers should weigh in (Andreas 
>> R. especially).
> Type "symbol" would be my preference, but it is difficult to estimate
> (for me) whether that involves a risk.
> However, this clearly is an issue beyond symbols alone. The same
> problem re-arises whenever we have to add new primitive types in the
> future. It doesn't seem like a sustainable strategy to fake any new
> type ever into an object. Perhaps it is less harmful on the long run
> if we took the chance to clarify _now_ that the set of strings
> returned by 'typeof' is not fixed, and should not be treated as such?

I could go for that (see my "int64" and "uint64" argument).

And as noted, IE has softened up the developers, or so I hear.

Someone who knows more should weigh in. I even heard that in IE JScript 
(or possibly even IE9/10 Chakra -- "JavaScript"), typeof can return 
"unknown"! True?


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