-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 04/03/2013 01:50 PM, Ethan Furman wrote: > On 04/03/2013 10:46 AM, Barry Warsaw wrote: >> On Apr 04, 2013, at 03:04 AM, Steven D'Aprano wrote: >> >>> On 04/04/13 01:16, Barry Warsaw wrote: >> >>>> the other built-in types-as-functions, so int() calls __int__() >>>> which must return a concrete integer. >> >>> Why must it? I think that's the claim which must be justified, not >>> just taken as a given. When we call n = int(something), what's >>> the use-case for caring that n is an instance of built-in int but >>> not of a subclass, and is that use-case so compelling that it must >>> be enforced for all uses of int() etc.? >> >> It's a consistency-of-implementation issue. Where built-in types >> are callable, they return concrete instances of themselves. This is >> true for e.g. list, tuple, dict, bytes, str, and should also be true >> of int.
Given that requirement, we still don't have to mandate that __int__ return an actual instance of the int type: the coercion could happen inside int() (as it would for any non-subclass). Tres. - -- =================================================================== Tres Seaver +1 540-429-0999 tsea...@palladion.com Palladion Software "Excellence by Design" http://palladion.com -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) Comment: Using GnuPG with undefined - http://www.enigmail.net/ iEYEARECAAYFAlFcgVcACgkQ+gerLs4ltQ4ScwCfScssK/Cv74lPitQxbygmk5h/ RGoAnj2yUEgmEgorJi8GZh0GEB/iJrN1 =0I+y -----END PGP SIGNATURE----- _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
