From: Florian Gross <flgr@...>
Date: 2005-01-20T05:26:01+09:00
Subject: Re: value by reference

Mark Hubbart wrote:

>>do_something if ref # always done
>>x = ref || y # x is always ref
> 
> Ah, I hadn't thought of that. I guess if you would need to
> de-reference in conditionals:
>   do_something if ref.__value__

Yup, #to_bool is really missing here.

>>Some of Ruby's C methods want their arguments to be instances of a
>>particular class. They won't even call the usual #to_x methods.
>>str.scan(ref) is one example of that.
> 
> I didn't know of that one. So String.scan doesn't use duck typing?

Lots of C methods don't even try to convert their arguments which is 
quite sad. There's no #to_re or #to_regexp. Because of that I have to 
use a huge work-around in Regexp::English that involves sub classing 
Regexp and recalling the Regexp#initialize method whenever the value 
changes...

>>Object.instance_method(:inspect).bind(ref).call calls the #inspect
>>method of the ref, not of the Object it refers to.
> 
> I would consider that a feature :) at a later time, a method could be
> added, __ref__, would would allow you to call normal ruby methods on
> the reference object; get its id, inspect it, etc.

I agree, I'm even using the above when I don't trust the methods the 
Object provides. (Sandboxes, DRb)

But it's still a case where the caller needs to be aware of refs and 
possibly dereference them manually.