From: Christoph Rippel <crippel@...>
Date: 2001-02-23T13:56:57+09:00
Subject: [ruby-talk:11364] Re: Array bugs?

> From: ts [mailto:decoux@moulon.inra.fr]
[...]

> C> same problem is probably also in hash  - and it extends
> 
>  Not yet found
ruby -e 'a={};a[a] = a; b ={}; b[a] = b; b == a'
> 
> C> to arrays which contain object with non-id based #== 
> C> methods.
> 
>  Do you have an example for this.

class UnOrderedPair
def ==(other)
	return false  unless other.kind_of?  UnOrderedPair
      return true if id == other.id
      return true if (@l == other.l ) && (@r == other.r)
      return  (@l == other.r ) && (@r == other.l)
end
def initialize(ll,rr)
	  @l = ll; @r = rr
end	
protected 
attr_reader    :l, :r
end

l = []; r=[]

pl = UnOrderedPair.new l,r
pr = UnOrderedPair.new r,l

l << pl; r << pr

pl == pr


Christoph