From: "Ball, Donald A Jr (Library)" <donald.ball@...>
Date: 2007-05-19T00:06:56+09:00
Subject: Re: questions about reimplementing core classes

> > 3. I had vaguely thought that the default freeze 
> implementation would 
> > freeze all instance variables, but it does not. Is this a 
> good way to 
> > implement freeze? (with the exception of the incorrect 
> return value?)
> No that is not a good way I am afraid. Please note that one 
> cannot freeze instant variables - I have a reason to be picky 
> here, I believe
> - but the objects they are referring to.
> Do you see the implications of a "deep" freeze now? The whole 
> program will probably get cold feet ;) as objects just 
> referenced in our object would be frozen.

Heh heh heh, that hadn't yet occurred to me, but your point's well
taken.

> However what you are doing is clever of course, you freeze 
> the objects you have created as containers for other objects 
> without freezing the objects the container references, do you 
> see how bad it would be again if your SortedHash froze all 
> contained objects?

Of course. But what I'm doing is fine, at least as far as it goes, yes,
since I have relatively simple internal data structures? If it were more
complex, it would be better to explicitly check frozen? in each of the
methods which could modify state? (which means i really ought to put in
a super call in my freeze method...)

- donald