[Python-Dev] [Python-checkins] cpython: Move PyUnicode_WCHAR_KIND outside PyUnicode_Kind enum

"Martin v. Löwis" martin at v.loewis.de
Sun Dec 18 21:04:24 CET 2011

Am 18.12.2011 20:45, schrieb Victor Stinner:
> On 18/12/2011 20:34, "Martin v. Löwis" wrote:
>>>    Move PyUnicode_WCHAR_KIND outside PyUnicode_Kind enum
>> What's the rationale for that change? It's a valid kind value, after
>> all, and the C convention is that an enumeration lists all valid values
>> (else there wouldn't be a need for an enumeration in the first place).
> PyUnicode_KIND() only returns PyUnicode_1BYTE_KIND, PyUnicode_2BYTE_KIND
> or PyUnicode_4BYTE_KIND. Outside unicodeobject.c, you are not supposed
> to see PyUnicode_WCHAR_KIND.

Why do you say that? It can very well happen, assuming you call
PyUnicode_KIND on a string that is not ready. That would be a
bug in the module, but people do make bugs when programming.

> For switch/case, it avoids the need of adding a dummy
> PyUnicode_WCHAR_KIND case (or a default case).

... and thus hides a potential source of errors, as people may
forget to call ready, and then fall through the case, letting
god-knows-what happen.

If the rationale is to simplify silencing compiler errors, I
vote for reverting the enumeration back to a macro list.


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