I redefine the '=:' and 'hash' methods of the elements contained in an
ordered collection. My aim is to check if anOrderedCollection contains any
duplicate object.
So I try the following code: 
(anOrderedCollection size ~~ anOrderedCollection asSet size)

I would be grateful if you might suggest another solution without using the
redefinition of the twin methods.

>I think that identity related issues is one of the most complex in OO
>Design.
I'll be interested in documents discussing these issues if any. 

Thanks,
Houssam
____
"Le paradis touche les pieds des mères..."
>>> http://csl.ensm-douai.fr/fakih
 

>-----Message d'origine-----
>De : squeak-dev-bounces at lists.squeakfoundation.org [mailto:squeak-dev-
>bounces at lists.squeakfoundation.org] De la part de stéphane ducasse
>Envoyé : vendredi 1 juillet 2005 12:27
>À : The general-purpose Squeak developers list
>Objet : Re: hash method
>
>Generally
>
>I use
>
>     iv hash bitXor: iv2 hash
>
>Following Kent beck best practices
>
>But now I learned that I want to avoid as much as possible to
>redefine = and hash
>and if this is just to sorted objects I used
>SortedCollection sortBlock: [:a :b| a iv > b iv] for example.
>
>I think that identity related issues is one of the most complex in OO
>Design.
>
>Stef
>
>Le 1 juil. 05 à 11:04, Houssam Fakih a écrit :
>
>> Hi,
>>
>>
>> When I redefine the = operation for a class I should redefine its
>> hash method.
>>
>> My question is about the definition of the hash method. I read that
>> the method must return a SmallInteger whose value is related to the
>> receiver. I would like to know if there is a general pattern
>> adopted in Squeak for that. I get a look in the Squeak classes but
>> it doesn’t help.
>>
>>
>> Thanks,
>>
>> Houssam
>>
>> ____
>>
>> "Le paradis touche les pieds des mères..."
>>
>> >>> http://csl.ensm-douai.fr/fakih
>>
>>
>>
>>
>