[Python-Dev] Intricacies of calling __eq__

[Maciej Fijalkowski]

On Wed, Mar 19, 2014 at 3:26 PM, Antoine Pitrou <solipsis at pitrou.net> wrote:
> On Wed, 19 Mar 2014 15:21:16 +0200
> Maciej Fijalkowski <fijall at gmail.com> wrote:
>
>> On Wed, Mar 19, 2014 at 3:17 PM, Antoine Pitrou <solipsis at pitrou.net> wrote:
>> > On Wed, 19 Mar 2014 15:09:04 +0200
>> > Maciej Fijalkowski <fijall at gmail.com> wrote:
>> >>
>> >> I would like to point out that instructing people does not really
>> >> work. Besides, other examples like this:
>> >>
>> >> if d[x] >= 3:
>> >>    d[x] += 1 don't really work.
>> >
>> > That's a good point. But then, perhaps PyPy should analyze the __eq__
>> > method and decide whether it's likely to have side effects or not (the
>> > answer can be hard-coded for built-in types such as str).
>> >
>> > Regards
>> >
>> > Antoine.
>>
>> Ok. But then how is it valid to have "is" fast-path?
>
> What do you mean?
>

I mean that dict starts with "is" before calling __eq__, so the number
of calls to __eq__ can as well be zero.