From: Hal Fulton <hal9000@...>
Date: 2003-12-07T13:47:20+09:00
Subject: Re: Attempted roadmap of future instance variables....

Jesse Tov wrote:

[snippage]

> I should write about Ruby, in case anyone's still reading, since I have
> a proposal.  Ruby's naming rules exist for a really good reason:  To
> make it easy to use differently-scoped variables without ever declaring
> anything about them.  (Unless Matz says differently, I guess.)  Adding a
> new kind of variable that requires a declaration, as some have suggested,
> would be pretty inconsistent.  Adding a new prefix (@_a) would be
> consistent, but it adds to the confusion.  On the other hand, it would
> be easy to search for where it breaks old code.
> 
> After a lot of discussion about this, it seems clear to me that the point
> of instance local variables isn't about privacy so much as preventing
> accidental collisions.  That calls for a solution that makes it easy
> to access parents' instance locals, while still differentiating their
> namespaces.  The proposed use of "namespace" seems a bit syntactically
> heavy, though.  So, I'm going to propose something analogous to the
> case of Foo versus ::Foo:
> 
>      @a         instance local
>      @::a       parent's instance local
>      @Foo::a    ancestor-named-Foo's instance local
> 
> It doesn't add anything new, since :: already exists for similar things.
> It's lightweight and non-restrictive, and seems to blend into the
> language pretty well to me.  Here's an example:

[snip snip]

At first glance, I think I like this.

> (Please forgive me for delurking in this fashion.)

De-lurk more often. You seem to reason well, not to mention spelling
and punctuation. :)

Of course, someone else may point out why this isn't good. I certainly
have not thought it through yet.

Hal