Yes, canEqual implementation also make #= be commutative. On Tue, Oct 3, 2017 at 11:11 AM, Denis Kudriashov <dionisi...@gmail.com> wrote:
> > 2017-10-02 17:30 GMT+02:00 Denis Kudriashov <dionisi...@gmail.com>: > >> >> 2017-10-02 17:13 GMT+02:00 Vitor Medina Cruz <vitormc...@gmail.com>: >> >>> I am sorry, not species, but #isKindOf istead of #= to compare classes. >>> >> >> It is bad idea. #= should be transitive. >> > > Oh, I used wrong word, shame on me :). I tried to say commutative. > > >> How you will generate it with isKindOf: logic? You need to know common >> parent. >> >> Also I not remember cases where I was needed two instances of different >> classes to be equal. >> And I can imaging the problems which it will lead to. >> >> >>> >>> On Mon, Oct 2, 2017 at 11:57 AM, Denis Kudriashov <dionisi...@gmail.com> >>> wrote: >>> >>>> >>>> 2017-10-02 16:37 GMT+02:00 Sean P. DeNigris <s...@clipperadams.com>: >>>> >>>>> >>>>> Two questions/comments about the generated code: >>>>> 1. #= >>>>> ... >>>>> self class = anObject class "should compare #species instead?" >>>>> ifFalse: [ ^ false ]. >>>>> ... >>>>> Typically, I've seen #species instead of #class in the guard statement. >>>>> Should we change it to that? >>>>> >>>> >>>> I doubt that it is important for domain classes. Because I never saw >>>> the user of #species which is not a kind of Collection. And for collections >>>> this refactoring is not valid anyway. >>>> >>>> >>>>> >>>>> >>>>> 2. #hash >>>>> ^ var1 hash bitXor: (var2 hash bitXor: var3 hash) >>>>> Is this implementation always safe? It's what I usually hand roll >>>>> based on >>>>> what I've seen, but Andres Valloud wrote a whole (large) book on >>>>> hashing, so >>>>> I've always wondered if I was missing something… >>>>> >>>>> >>>>> >>>>> ----- >>>>> Cheers, >>>>> Sean >>>>> -- >>>>> Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html >>>>> >>>>> >>>> >>> >> >
