From: dblack@...
Date: 2003-05-09T08:11:43+09:00
Subject: Re: Can a global be a constant?

Hi --

On Fri, 9 May 2003, Hal E. Fulton wrote:

> ----- Original Message -----
> From: "Brian Candler" <B.Candler@pobox.com>
> To: "ruby-talk ML" <ruby-talk@ruby-lang.org>
> Sent: Thursday, May 08, 2003 5:44 PM
> Subject: Re: Can a global be a constant?
>
>
> > On Fri, May 09, 2003 at 07:04:40AM +0900, Jim Freeze wrote:
> > > Ok. I didn't realize that $, @, and @@ were considered part
> > > of the name. Makes sense now.
> >
> > And you'll see this if you try to access one of these things using the
> > symbol:
> >
> >   class Foo; end
> >   a = Foo.new
> >   a.instance_variable_set(:@bar,1) #>> OK
> >   a.instance_variable_set(:bar,1)  #>> NameError: 'bar' is not an
> >                                        instance variable name
>
> Yet this is potentially confusing, because a
> line like attr_accessor :foo does create an
> accessor for @foo.
>
> I suppose the rationale is that you're specifying
> the symbol corresponding to the method name rather
> than the instance variable.

There are lots of fun things you can do with names when you start
setting them manually:

  $ cat weird.rb
  class << o=Object.new
    define_method("&!#?") { puts "Weird method name!" }
  end

  o.send("&!#?")

  $ ruby weird.rb
  Weird method name!

:-)


David

-- 
David Alan Black
home: dblack@superlink.net
work: blackdav@shu.edu
Web:  http://pirate.shu.edu/~blackdav