From: Jonathan Leighton <lists@...>
Date: 2006-03-26T23:25:26+09:00
Subject: Re: Noob: use of the double colon

On Sun, 2006-03-26 at 22:33 +0900, dblack@wobblini.net wrote:
> Hi --
> 
> On Sun, 26 Mar 2006, NuclearFusion wrote:
> 
> > Hi,
> >
> > there seems to be more than one way to execute class methods.
> > I've seen the form (I use the classmethod new as an example):
> >   newObject = Classname::new
> > but also
> >   newObject = Classname.new
> > Bothe seem to work OK.
> > Is there a difference? If yes, what is the difference?
> 
> They do both work.  I've never understood why the :: exists for this
> purpose, since the . is the normal way of sending messages to objects
> and works perfectly well whether or not the receiver is a class.  It's
> on my very short list of things I'd like to see removed from Ruby.
> 
> > Also I see :: being used in the context of modules. Can you tell me
> > about that as well?
> 
> That's for looking up names of constants in nested scopes:
> 
>    module M
>      X = 1
>    end
> 
>    puts M::X   # 1

While we're on the topic -- I've never exactly understood what placing
the double colon at the beginning does? eg...

::FooModule::FOO_CONSTANT

?

Cheers

-- 
Jonathan Leighton
http://turnipspatch.com/ | http://jonathanleighton.com/ | http://digital-proof.org/