From: Robert Dober <robert.dober@...>
Date: 2006-06-26T21:23:34+09:00
Subject: Re: Ruby and Java equality usage

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On 6/26/06, Alexandru Popescu <the.mindstorm.mailinglist@gmail.com> wrote:
>
> Thanks Robert. I have used that information and I am even linking to
> it. The problem I was facing was to explain why == and eql? are both
> needed, and when their implementation may be different.
>
> Ok I knew I missed something.
Personally I find it quite useful to have "==" which I can adapt to my
needs, knowing that I can always count on "eql?" for object equality, I
might do things like this:

class MyString < String
     def ==( otherString )
            raise SomeException unless String === otherString
            self.downcase.eql?( otherString.downcase )
     end
end

x=MyString.new("Alfa")
x == "alfa" ==> true
x.eql?("alfa") ==> false

Now I think it is perfectly sane to say, no I think this is confusing I will
keep my "==" and my "eql?" identical.
However be prepared that others will not ;)

Cheers
Robert

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