Re: [WebIDL] Dictionaries and undefined

Brendan Eich:
>> Agreed. Ad-hoc argument processing in JS today may use
>> arguments.length, or undefined testing (possibly even
>> null-or-undefined testing via " == null"). I continue to think
>> arguments.length is the best way for IDL.

Jonas Sicking:
> This doesn't match the feedback we got in the thread where we
> decided on undefined-checking rather than arguments.length.
>
> I don't really have a strong feeling either way as I don't have
> enough experience with how JS developers think.

Yes, we did just resolve as part of the previous Last Call comment 
resolution lot that undefined is treated as a missing argument.  Making 
dictionary members treat undefined as an explicit value would be 
inconsistent with that.  I'd rather have both be the same, and given the 
reasonably extensive discussion that were already had with the function 
calling case, I'd lean on the side of making undefined the same as an 
unspecified dictionary member.

Received on Sunday, 30 October 2011 22:23:38 UTC