From: "David A. Black" <dblack@...>
Date: 2005-05-08T00:57:36+09:00
Subject: Re: object reference handle (like perl's reference to scalar)

Hi --

On Sat, 7 May 2005, Dave Burt wrote:

> I don't think what I've done here is anything like that. The concept of a
> reference here is just a wrapper or pointer, and it has to have a use. Sure,
> it causes problems in C and Perl, and Ruby definitely offers more elegant
> tools fo most of the problems that are solved in those languages with
> pointers, but I'm coming from a Rubyist's perspective here, and all I'm
> proposing is a new container, for a single object.
>
> And I think Austin's PDF::Writer example is one case where it's useful (that
> is, passing an object by reference into a method so the method can replace
> the object).

It's a bit misleading to call it "passing by reference".  In Ruby, all
passing is by value.  Many values happen to be references.  If you
have a Ref object, and pass it to a method, you are passing it by
value-which-is-a-reference.  That doesn't change, even if the object
itself is of a class called Ref or Reference or Pointer, etc.

I understand that when you then *do* something with that object, you
are manipulating a second object, in a manner that emulates non-Ruby
reference semantics.  But still, as far as what's happening when you
call the method with a Ref argument goes, it's still business as usual
for Ruby.


David

-- 
David A. Black
dblack@wobblini.net