From: "David A. Black" <dblack@...>
Date: 2004-12-06T13:12:16+09:00
Subject: Re: Freezing Variable Assignment

Hi --

On Mon, 6 Dec 2004, Nicholas Van Weerdenburg wrote:

> Hi,
> 
> Is there a feature to freeze variable assignment?
> 
> e.g.
> a="hello"
> a.assignfreeze
> a="goodbye"  # ===> generates exception

I tend to think this would be a pretty radical reconceptualization of
how variable identifiers relate to objects, rather than just a
feature.  At the very least it would probably have to be something
like:

   freeze_identifier(:a)

as opposed to sending a message to the object referenced by 'a'.  (In
your example you'd be sending the message 'assignfreeze' to the string
"hello".)  

> Or, in a related vein, a type freeze, so that only similar objects can be added.

You'd have to define 'type' and/or 'similar object', which isn't
always easy :-)


David

-- 
David A. Black
dblack@wobblini.net