On Thu, Dec 28, 2017 at 4:51 AM, Victor Stinner <victor.stin...@gmail.com> wrote: > Hi, > > I like the new version of the PEP using "read only mapping" and > copy_context(). It's easier to understand.
Thanks, Victor! > > I'm ok with seeing a context as a mapping, but I am confused about a context > variable considered as a mapping item. I still see a context variable as a > variable, so something which has a value or not. I just propose to rename > the default parameter of the ContextVar constructor. As Nathaniel already explained, a 'default' for ContextVars is literally a default -- default value returned when a ContextVar hasn't been assigned a value in a context. So my opinion on this is that 'default' is the less ambiguous name here. [..] > > * a read-only attribute ``Token.old_value`` set to the value the > variable had before the ``set()`` call, or to ``Token.MISSING`` > if the variable wasn't set before. > > > Hum, I also suggest to rename Token.MISSING to Token.NOT_SET. It would be > more conistent with the last sentence. I like MISSING more than NOT_SET, but this is very subjective, of course. If Guido wants to rename it I rename it. > C API > ----- > > > Would it be possible to make this API private? We want _decimal and numpy to use the new API, and they will call ContextVar.get() on basically all operations, so it needs to be as fast as possible. asyncio/uvloop also want the fastest copy_context() and Context.run() possible, as they use them for *every* callback. So I think it's OK for us to add new C APIs here. > > 2. ``int PyContextVar_Get(PyContextVar *, PyObject *default_value, > PyObject **value)``: > (...) ``value`` is always a borrowed > reference. > > > I'm not sure that it's a good idea to add a new public C function which > returns a borrowed reference. I would prefer to only use (regular) strong > references in the public API. Sure, I'll change it. Yury _______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
