From: Ryan Davis <ryand-ruby@...>
Date: 2003-06-21T08:46:07+09:00
Subject: Re: Copying RVALUE


On Friday, June 20, 2003, at 01:52  PM, why the lucky stiff wrote:

> Tanaka Akira (akr@m17n.org) wrote:
>> One idea is creating empty array just after the anchor.
>
> This is an idea, though I'd like something more general.  The anchor
> could be an array, a hash, an object, a struct, anything with depth.
> Using that technique, everytime I want to support some new kind of
> RVALUE, I have to change my implementation.
>
> What I'm asking for is the equivalent of a pointer-pointer in the 
> symbol
> table, which I think could be valuable to extension writers.  Either

Couldn't you use a one element array as a pointer-pointer? I assumed 
that's what Tanaka was hinting at.

> access to copy RVALUEs _or_ a reference struct, which could allow
> me to use a VALUE as a pointer to another VALUE.  I have looked at
> WeakRef, but it won't allow me to reassign the reference.

Smalltalk's Object#become: would rule here.