Es4-discuss Digest, Vol 3, Issue 2

Brendan Eich brendan at
Wed May 2 12:42:05 PDT 2007

On May 2, 2007, at 12:37 PM, Kris Zyp wrote:

> I for one would love to see the ability to set DontEnum on  
> properties. This is a very logical thing do with some properties  
> and is very useful in code interopibility even when you are not  
> trying to achieve a pure "Hash". It doesn't seem like a very big  
> addition either (vs sharps).

Everyone has read 
enumerability.html by now, right?

> Also, having function/methods as slots that can be swapped with  
> values seems like a fundamental concept of ES and its simplicity  
> and consistency. It would seem bizarre to me to set toString to a  
> primitive and expect anything but an error when coercion tried to  
> convert the object to string. ES3 throws an error, and it seems  
> totally logical that it should.


> Also, it seems weird that we use the term "Hash", isn't Map or  
> Dictionary more correct? Isn't a Hash just the most natural and  
> efficient implementation of a Map or Dictionary? Maybe I am just  
> used to Java terminology. Of course we know what each other is  
> talking about, so it is not really a big deal.

Hash is just shorter, and conventional among Perl and (I think)  
Python and probably Ruby folks. We wouldn't necessarily use it; the  
late-breaking attempt to add a class with no helpful syntax (the  
attempt that foundered in part on concern about weak reference  
support being implied) was called Dictionary.

(Wow, I didn't know anyone read the digest.)


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