Łukasz Langa added the comment: Having all information in place, I think it's acceptable for both of us to implement preference for explicit registration, leaving both ways of implicit registration as equally binding. The latter is future proof in the sense that if we change our minds later, it's going to be easier to lift the dispatch conflict than to introduce conflicts where there weren't any before.
The point you're making about `Abc.register(Cls)` being external to the definition of Cls and thus somewhat dependant on import order and other machinery is what convinced me in the end. I also like the proposed terminology and think it should appear in the documentation. I created a modified patch. This wasn't as tricky as I feared but required me to formulate an explicit rule: all implicit ABCs are inserted in the MRO of a given class directly after the last explicit ABC in the MRO of said class. One open question is what to do with the algorithm described in PEP 443 which no longer describes the state of things exactly. Although the said PEP is final, some parts of the discussion on this issue just beg to be included in the "Abstract base classes" section. What do you think we should do? Answering your questions, neither scanning the source code nor using a private attribute on ABCMeta can be considered an *obvious* way to distinguish between registered and inferred ABCs. The former is static analysis which might involve opening (and understanding) a number of black boxes, the latter is fragile by definition and breaks the abstraction (again, opening a black box). This is why we introduced a public API to get the current cache token [1]_. As for dispatch differences between MutableMapping and dict, it's in my previous message (191947) on the issue, classes G and H. On an unrelated note, thank you for correcting my English. It seems that after achieving a level of fluency that is bearable to native speakers, nobody corrects my mistakes anymore. This in turn places me in an unfortunate plateau. And yes, I'm well aware that my gut would win no popularity contest, especially when the BDFL's one is a contender :-) I just hope this doesn't automatically make the feelings of my own gut invalid. .. [1] http://bugs.python.org/issue16832 ---------- Added file: http://bugs.python.org/file30733/issue18244.diff _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue18244> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
