How complex can a parameter default expression be?

Dave Herman dherman at
Sat Dec 22 05:30:32 PST 2007

That seems like an unnecessary restriction, no? Since argument 
evaluation is already restricted to left-to-right, we could allow 
default-expressions to refer to earlier arguments without too much 
trouble, unless I'm missing something obvious.


Brendan Eich wrote:
> On Dec 21, 2007, at 4:53 AM, P T Withington wrote:
>> Can it refer to previous parameters?  Assign to them?  Is this legal?
>>    function foo (a:t = x, b:u = (a = y, z))
> AFAIK the formal parameters (bound in the variable object of the  
> activation of foo) are not in scope when default parameters are  
> computed.
> /be
> _______________________________________________
> Es4-discuss mailing list
> Es4-discuss at

More information about the Es4-discuss mailing list