On Sat, Sep 10, 2016 at 5:23 PM, Guido van Rossum <gu...@python.org> wrote:
> No. PEP 505 actually solves the problem without ever catching > AttributeError. Please read it. > I read it again (I did a year ago, but reviewed it now). I hadn't been thinking that the *mechanism* of a new None-coalescing operator would actually be catching an exception. It could (and should) work differently if it becomes syntax. What I was getting at with "essentially" was that it would *do the same thing* that an AttributeError does. That is, if `x.foo` can't be evaluated (i.e. x doesn't have an attribute 'foo'), then access is informally "an error." The hypothetical "x?.foo" catches that "error" and substitutes a different value. The particular implementation under-the-hood is less important for most programmers who might use the construct (and I think documentation would actually give an informal equivalent as something similar to what I put in the NoneCoalesce class). -- Keeping medicines from the bloodstreams of the sick; food from the bellies of the hungry; books from the hands of the uneducated; technology from the underdeveloped; and putting advocates of freedom in prisons. Intellectual property is to the 21st century what the slave trade was to the 16th.
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