From: Ross Bamford <rosco@...>
Date: 2005-12-31T20:06:27+09:00
Subject: Re: Fixnums can have instance variables?  Cool.

On Fri, 30 Dec 2005 07:46:17 -0000, <gwtmp01@mac.com> wrote:

> This really surprises me:
>
> 3.instance_variable_set("@unbelievable", "believe it!")
>
> puts 3.instance_variable_get("@unbelievable")		# -> "believe it!"
>
> which led me to:
>
> class Fixnum
>    attr_accessor :note
> end
>
> 13.note = "a baker's dozen"
> 25.note = "5 squared"
>
> notes = [13, 21, 25].collect { |x| x.note }		# ["a baker's dozen", nil,  
> "5 squared"]
>
> Am I the only person with their jaw on the ground?
>

:D That one got me, too. I kind of hinted at it in some nuby code I wrote  
(http://roscopeco.co.uk/code/noob/bitwise.html). Also check out:

irb(main):001:0> class Symbol
irb(main):002:1> attr_accessor :too
irb(main):003:1> end
=> nil
irb(main):004:0> :foo.too
=> nil
irb(main):005:0> :foo.too = 66
=> 66
irb(main):006:0> :foo.too
=> 66

This struck me as pretty cool, too:

irb(main):007:0> SomethingElse = Symbol
=> Symbol
irb(main):008:0> :foo.is_a? SomethingElse
=> true

God, Ruby is *good*

-- 
Ross Bamford - rosco@roscopeco.remove.co.uk