[squeak-dev] SequenceableCollection #= method in current trunk differs from Squeak 5.2

Chris Muller asqueaker at gmail.com
Tue Jun 30 22:31:35 UTC 2020

Might be worth reopening this discussion.  ANY dependencies on #class seem
like a bad thing to me, especially while it's still an in-lined message.
Below is the MC version that did it.  Looks like the time to change this
19-year old core method went from "itch" to trunk in all but just a few

Name: Collections-nice.820
Author: nice
Time: 12 February 2019, 11:56:35.262017 pm
UUID: bb383133-067c-4133-987b-c481a7de69c7
Ancestors: Collections-ul.819, Collections-cbc.813

Definitively abandon SequenceableCollection equality tests based on equal

Old behaviour can still be obtained thru hasEqualElements: but the default
is to not try to support such trans-class equality feature because it is
much too complex.

Particularly Interval are no more equal to Arrays with same sequence. We
can thus optimize hash a bit more and fix the old bugs of equa objects with
different hashes. Merge Collections-cbc.813 for this and rehashAll in

There are not so many classes concerned by this change, mainly RunArray,
Interval and LinkedList:

Collection withAllSubclasses select: [:e | [e basicNew species ~= e] on:
Error do: [false]]
-> an OrderedCollection(WeakRegistry LinkedList Interval ByteCharacterSet
CharacterSetComplement LazyCharacterSet WideCharacterSet ShortRunArray
Semaphore Mutex TextLineInterval WeakArray Monitor MCVersionName ByteSymbol

We will have to change the tests that rely on such equality.

On Mon, Jun 29, 2020 at 3:42 AM Nikolay Suslov <nsuslovi at gmail.com> wrote:

> Thanks Levente,
> Yes, seems to be RFB/VNC from the SqueakSource-SqF project page
> is outdated (at least it is working in Squeak 5.2 and not in 5.3 and
> later). Your version works fine!
> However, it is interesting what was the reason for that change just in
> SequenceableCollection #=. As Set, Bitset, SortedCollection etc. classes
> still use species comparison in #= (checking they have the same set of
> keys)?
> Best regards,
> Nikolai
> On Mon, Jun 29, 2020 at 3:43 AM Levente Uzonyi <leves at caesar.elte.hu>
> wrote:
>> Hi Nikolai,
>> On Mon, 29 Jun 2020, Nikolay Suslov wrote:
>> > Hello all,
>> > Figuring out, could we go back to the previous version of
>> SequenceableCollection #= method (as in Squeak 5.2), to check if the
>> receiver is equivalent to the otherCollection by using "self species ==
>> otherCollection species",
>> > instead of "self class = otherCollection class"?
>> IIRC there was a good reason for that change though I can't recall
>> what it was. I'm sure the mailing list remembers.
>> > The current version of #= method breaks code in different places. For
>> example the RFB/VNC server gives wrong results starting from an
>> authentication process, where RFBMessage is the ByteArray subclass and
>> implements #species.
>> If you're looking for a fix, try this:
>> http://leves.web.elte.hu/squeak/RFB-ul.18.mcz
>> Levente
>> >
>> > Best regards,
>> > Nikolai
>> >
>> >
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