From: Charles Oliver Nutter <charles.nutter@...>
Date: 2007-10-28T14:04:57+09:00
Subject: Re: How fast does your Ruby run?

M. Edward (Ed) Borasky wrote:
> Let me re-phrase that ... how do I know when I'm coding that I'm not 
> going to ask for it? Do I need to explicitly call/require/include 
> something to get it?

Well, you need to explicitly reference ObjectSpace in most cases to 
access it, right?

In general, the tricky bit is that there's at least one key library in 
stdlib that depends on ObjectSpace: test/unit, which uses it to locate 
tests. However I've implemented in JRuby the ability to walk all child 
classes from a parent class, which provides the each_object(Class) used 
in test/unit. Currently, you can turn off ObjectSpace support in JRuby 
and still have test/unit run.

Raising an error might be a better way to ensure people don't run code 
without ObjectSpace enabled, certainly. But maybe they don't care?

It's an open question at the moment, but I don't see that there's any 
way ObjectSpace is going to have good performance on these new 
implementations where we don't have intimate control over memory and GC. 
I expect this is going to be a concern for IronRuby/Ruby.NET too. As far 
as I know, JRuby's the only general-purpose VM implementation of Ruby 
that's even *attempted* to make ObjectSpace work.

- Charlie