Message 397569 - Python tracker

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Author	serhiy.storchaka
Recipients	gvanrossum, kj, serhiy.storchaka
Date	2021-07-15.16:47:27
SpamBayes Score	-1.0
Marked as misclassified	Yes
Message-id	<1626367647.84.0.0409964892759.issue44642@roundup.psfhosted.org>
In-reply-to

Content
It is only reminder that our test for NewType is arbitrary. And it is not compatible with PR 9951. Possible solutions are: 1. Make NewType a class and add more strict test. Pro -- we can make arbitrary repr, contra -- it has small negative effect on performance. See issue34963. 2. Remove the test for NewType at all and allow or-ing types and arbitrary functions. 3. Introduce a special attribute to distinguish unionable objects. It will make the code of unionobject.c simpler. I lean towards option 1 (not excluding 3). Small performance losses seem inevitable.

It is only reminder that our test for NewType is arbitrary. And it is not compatible with PR 9951. Possible solutions are:

1. Make NewType a class and add more strict test. Pro -- we can make arbitrary repr, contra -- it has small negative effect on performance. See issue34963.

2. Remove the test for NewType at all and allow or-ing types and arbitrary functions.

3. Introduce a special attribute to distinguish unionable objects. It will make the code of unionobject.c simpler.

I lean towards option 1 (not excluding 3). Small performance losses seem inevitable.

History
Date	User	Action	Args
2021-07-15 16:47:27	serhiy.storchaka	set	recipients: + serhiy.storchaka, gvanrossum, kj
2021-07-15 16:47:27	serhiy.storchaka	set	messageid: <1626367647.84.0.0409964892759.issue44642@roundup.psfhosted.org>
2021-07-15 16:47:27	serhiy.storchaka	link	issue44642 messages
2021-07-15 16:47:27	serhiy.storchaka	create