On Thu, Nov 15, 2018 at 5:36 PM Eliot Miranda <eliot.miranda at gmail.com>
wrote:

> Hi Bert,
>
> On Thu, Nov 15, 2018 at 4:38 PM Bert Freudenberg <bert at freudenbergs.de>
> wrote:
>
>> Somehow I missed Eliot's version, but unsurprisingly he had exactly the
>> same idea (use "last" not "stop" for hash). I'd still think bitXor: is
>> preferable to bitOr, that is the standard way in almost all hash methods.
>> But ...
>>
>> BUT: I forgot about the super fallback in #=. That makes this discussion
>> pretty much moot, because since
>>
>> #(1 2 3) = (1 to: 3) "true"
>>
>> is true, this must also be true:
>>
>> #(1 2 3) hash = (1 to: 3) hash  "must be true"
>>
>> So the only proper fix IMHO is to remove #hash from Interval (or replace
>> it with ^super hash and a proper comment)
>>
>
>
> We discussed this a couple of weeks ago.  There is no need for
>     #(1 2 3) = (1 to: 3)
> to be true.
>     #(1 2 3) = #[1 2 3]
> isn’t true.  And we have hasEqualElements:.  So a more coherent approach
> is for the hack that makes intervals equal to arrays be discarded, and the
> hashes kept distinct.
>
>
And I agreed with you weeks ago, but looking at it closer, the code
specifically says Interval is a species of Array.
Interestingly, ByteArray, which is a subclass of ArrayedCollection, doesn't
set its species, so its species is ByteArray.  Which is desirable.

If we change the Interval #species to not be array, then many things break
with Interval - most notably #select: and #collect:, so a major overhaul
would be in store for that part of the code.

In line with Bert's allusion, if we removed the super = call, then #= is no
longer associative between Interval's and Arrays:
(1 to: 3) = #(1 2 3) "false"
#(1 2 3) = (1 to: 3)" true"

So, I'm just fixing the Interval only part and punting on the issue between
Interval and Array for now.

-cbc


>
>> - Bert -
>>
>>
>>
>
> --
> _,,,^..^,,,_
> best, Eliot
>
>
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