Function.length and Default Parameters

Brendan Eich brendan at
Fri Oct 12 13:53:36 PDT 2012

One more question: are these optional parameters the kind that would 
want to use parameter default values if self-hosted? If so, that would 
cement the case for the current spec. Kevin's counter-example would be a 
"it hurts when I do this!" "don't do it!" thing.


Norbert Lindenberg wrote:
> String.prototype.localeCompare
> Number.prototype.toLocaleString
> Date.prototype.toLocaleString
> Date.prototype.toLocaleDateString
> Date.prototype.toLocaleTimeString
> Intl.Collator
> Intl.Collator.supportedLocalesOf
> Intl.NumberFormat
> Intl.NumberFormat.supportedLocalesOf
> Intl.DateTimeFormat
> Intl.DateTimeFormat.supportedLocalesOf
> the function returned by Intl.DateTimeFormat.prototype.format
> ...are all specified in the ECMAScript Internationalization API Specification as taking optional arguments, but not counting them towards the value of their length properties.
> Norbert
> On Oct 12, 2012, at 11:53 , Brendan Eich wrote:
>> Yes, so given the case Kevin raises of default-ful followed by default-less I agree with Kevin: length should reflect all but rest (if present).
>> Allen, what built-ins would this break, do you know from checking what built-ins break under the current draft's rule?
>> /be
> _______________________________________________
> es-discuss mailing list
> es-discuss at

More information about the es-discuss mailing list