From: daz <dooby@...10.karoo.co.uk>
Date: 2005-11-07T00:17:11+09:00
Subject: Re: what does --can't define singleton method-- mean?


Sean O'Halpin wrote:
> On 11/6/05, Daniel Sch�le wrote:
> > irb(main):014:0* class << Complex
>
> You're using the wrong syntax here. To re-open a class, just use
> normal class definition syntax:
>

I think Daniel was, correctly, trying to limit his change
to his own object.  He didn't want to affect the class.

Using 'Coo' in place of 'Complex' works as he would have expected:

class Coo
  def angle
    90
  end
end

myc = Coo.new
def myc.angle
  88
end
p myc.angle  #-> 88


alt_myc = Coo.new
# alternative-style definition to def myc.angle
class << alt_myc
  def angle
    22
  end
end
p alt_myc.angle  #-> 22


# Coo class remains unaffected
c = Coo.new
p c.angle  #-> 90



Fortunately, the gurus stepped in with an explanation :-)


daz