From: Chris Hulan <hulachr@...>
Date: 2006-07-07T04:11:37+09:00
Subject: Re: Achieving Equality

unknown wrote:

>> I get a == rwd #=> true ?
> 
> Ah, it's simplified example of what I'm actually doing. So in this case
> the integers auto-coerce it seems. Try:
> 
>     a, b = "1", "1"
> 
> Which is probably a clue that can can be doen via #coerce, but I'm not
> sure how.
> 
> T.

I suggest modifying your == method to:
def ==( other )
    #p "#{@read.call} == #{other.inspect}"
    if other.kind_of?(RWDelegator)
      other == @read.call
    else
      @read.call == other
    end
end

To compare to other objects you can:
1) write conversion methods (i.e. to_s) and than convert the RWDelegator 
to the appropriate type when comparing (i.e. rwd.to_s == "1")

2) re-write the conversion methods of the other classes to handle your 
RWDelegator class appropriately:
class String
  alias old== ==
  def ==(other)
    if other.kind_of(RWDelegator)
      other == self
    else
      old==(other)
    end
  end


Cheers

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