From: matz@... (Yukihiro Matsumoto)
Date: 2001-05-30T10:08:55+09:00
Subject: [ruby-talk:15993] Re: How to enumerate known subclasses?

Hi,

In message "[ruby-talk:15974] Re: How to enumerate known subclasses?"
    on 01/05/30, Stefan Matthias Aust <sma@3plus4.de> writes:

|Sure. That could be easily added but are there any arguments against
|automatically maintaining a subclasses array for each class.
|Smalltalk does it that way.

Mostly implementation issue.  Implementing subclasses array requires
additional 4 bytes for each object.  There may be better
implementation maybe.

|And what's about allInstances, a way to efficently enumerate only the
|instances of a given class.  Any thoughts on that topic?

This would require more memory (to do it efficiently).  I'm not yet
sure if it worth it.

							matz.