Subj : Re: Private Data and Prototype Inheritance
To   : Kevin Lindsey <kevin@kevlindev.com>
From : Brendan Eich <brendan@meer.net>
Date : Fri Jan 09 2004 05:56 pm

Kevin Lindsey wrote:

>>Alternatively, you could avoid private data and use property storage.
>>Then delegation works as usual.
> 
> Ah, OK.  So, I would setProperty my private data in the native base class'
> constructor.  Then, using Line.apply(this, arguments), the derived object
> will get its own version of the "private data" property.  That makes sense.

I actually wondered why you need a private data structure, instead of 
just x, y, etc. properties that store numbers.

> Is there a idiom or recommended way of converting to and from jsvals and
> pointers?  It seems that I would have to use a jsdouble or string since ints
> are shifted internally.

JSVAL_TO_PRIVATE and PRIVATE_TO_JSVAL, to hide the 
otherwise-potentially-object-like private data struct address from the 
GC (the address must be 0 mod 2).  But again, can you avoid using 
private data structs altogether and just store the members of the struct 
as discrete properties?

/be

.