From: Daniel Nugent <nugend@...>
Date: 2006-02-24T10:08:39+09:00
Subject: Re: lazy.rb 0.9.5 -- transparent futures!

I don't think I understand what'sgoing on th... oh wait.  I see.

both table_name and name are pointing to "CUSTOMERS" and then only
table_name is pointing to "MONKEYS"

Yes, see, the thing that's important to consider is that I'm dumb.

*tries out Mental's examples, figures out how they work*

...

Woah, that's some powerful ju-ju.  Maybe I should go and futz with
GhostWriter again anyhow...

On 2/23/06, Jim Weirich <jim@weirichhouse.org> wrote:
> Daniel Nugent wrote:
> > table_name = "CUSTOMERS"
> > x = promise {table_name.dup}
> > table_name = "MONKEYS"
> > puts x
> > =>"CUSTOMERS"
> >
> > Would avoid the problem.  Though it's good to point out that you
> > likely want to avoid changing the state of any variable that's
> > captured by a promise closure (unless of course you plan on exploiting
> > just that).
>
> Hmmm ... I just tried it and got "MONKEYS" for the result.  It makes
> sense becase by the time table_name is dup'ed in the promise, it has
> already been modified.
>
> This would do it:
>
>    def table_promise(name)
>      promise { name }
>    end
>
>    table_name = "CUSTOMERS"
>    x = table_promise(table_name)
>    table_name = "MONKEYS"
>    puts x  # => "CUSTOMERS"
>
> --
> -- Jim Weirich
>
>
>
> --
> Posted via http://www.ruby-forum.com/.
>
>


--
-Dan Nugent