logo       

Re: reimplementing #= and #hash: msg#00124

lang.smalltalk.squeak.beginners

Subject: Re: reimplementing #= and #hash

Hi Janko,

Thanks for your help. Your code makes it clear.

Ching

On 9/23/07, Janko Mivšek <janko.mivsek@xxxxxxxxxx > wrote:
Hi Ching,

#= is test for equality while #== is test for identity. What do you
probably want is to override #= to compare two PoolQueues if they are
equal or not. But what "equal" means in your case is on you to define.
Maybe something like this:

PoolQueue>>= anotherPoolQueue

   ^(self member = anotherPoolQueue member)
        and: [self processor = anotherPoolQueue member]

But be sure that also member and processor instvars understand #= in a
correct way. All numbers, strings, symbols etc. understand equality as
expected.

I hope this helps a bit.
Janko


Ching de la Serna wrote:
> Hi List,
>
> I have a Class PoolQueue which has instvars 'member' and 'processor'. I
> find that an instance of PoolQueue when placed in an OrderedCollection
> can no longer be considered equal. I suppose I have to reimplement #=
> and #hash to allow PoolQueue instances to be compared.
>
> My problem: how do I implement #hash? Or stated another way, what does
> #hash accomplish?
>
> Thanks in advance.
>
> Ching.
>

--
Janko Mivšek
AIDA/Web
Smalltalk Web Application Server
http://www.aidaweb.si
_______________________________________________
Beginners mailing list
Beginners@xxxxxxxxxxxxxxxxxxxxxxxxxx
http://lists.squeakfoundation.org/mailman/listinfo/beginners

_______________________________________________
Beginners mailing list
Beginners@xxxxxxxxxxxxxxxxxxxxxxxxxx
http://lists.squeakfoundation.org/mailman/listinfo/beginners
<Prev in Thread] Current Thread [Next in Thread>
Google Custom Search

News | FAQ | advertise