Separating a Hash type from Object

[Andrew Dupont]

On May 2, 2007, at 1:40 AM, Brendan Eich wrote:
> Indeed, #. etc. is just a thought experiment. But just providing  
> the ability to override . and [] wouldn't help so much without a  
> default implementation -- it would force everyone wanting a hash  
> unpolluted by Object.prototype to reinvent the wheel.

And there's the rub: how do we make a default implementation without  
introducing too much magic? No matter how we do it, a Hash class  
would introduce a completely different relationship between an object  
and its properties.

Reinventing the wheel is less surprising to developers because it's  
their wheel and they know how it works. But I think the initial  
unpleasantness of special-casing Hash is better than the ongoing pain  
of each developer writing his own implementation of hashes.

I'm entirely in favor of a way to override "." and "[]", whether or  
not ES4 introduces a magic Hash class. That, at least, gives the  
developer a chance to solve the problem on her own.

Andrew