From: "Wesley J. Landaker" <wjl@...>
Date: 2003-09-05T05:57:50+09:00
Subject: Re: how to get the list of all classes?

Apparently, Mark J. Reed recently wrote:
> On Fri, Sep 05, 2003 at 05:01:50AM +0900, Ryan Pavlik wrote:
>> > $ ruby -e 'x = []; ObjectSpace.each_object { |o| x << o if o.class ==
>> > Class }; p x'
>> <snip>
>>
>> This is probably quicker if you do:
>>
>>     x = []
>>     ObjectSpace.each_object(Class) { |c| x << c }
>>
>> ..so you don't have to iterate through thousands of non-Class objects.
>
> It seems odd to me that ObjectSpace doesn't mixin Enumerable, but
> that's easily remedied:
>
> 	module ObjectSpace
> 	    class << self
> 	        include Enumerable
> 		def each(*args, &block) each_object(*args, &block) end
> 	    end
> 	end
>
> Then you can just do this:
>
> 	ObjectSpace.find_all { |c| c.class == Class }
>
> Although it is still, as noted above, probably less efficient than
> passing Class to each_object.  But it's an aesthetic improvement,
> I think.  I mean, the idea of having to iterate over
> a collection with a block that does nothing but an array append, just
> to get the collection into array form, seems very backwards to me.

I agree that having ObjectSpace enumerable would make sense. Actually, the
first thing I tried when I saw the original message was:

ObjectSpace.select { |x| x.class == Class }

... but then I realized that it wasn't Enumerable.

Wes

Wes