On 01/02/2014 04:06 PM, Chris Angelico wrote:
Here's a crazy idea. Suppose we have a "sticky falseness" that can
quietly propagate through an expression the way a NaN can... then we
could just float that right through the .group() call.
class truth:
def __new__(cls, x):
if x: return x
return object.__new__(cls)
def __bool__(self):
return False
def __getattr__(self, name):
return self
def __call__(self, *args, **kwargs):
return self
def __repr__(self):
return repr(False)
Pass any object through truth() and it'll either stay the same (if
it's true) or become this object (if it's false). You can then carry
on with other method calls, and they'll all happily return false.
An interesting idea. You'd need to add (at least) __getitem__, and I'll
probably call it `maybe`, myself. ;)
(I'm not sure if I'm using __new__ correctly; I've never actually done
it in production code, and the info I found online was mainly Py2
examples. Should that be done with super(), or is that applicable only
once there's an actual instance with a real MRO?)
I haven't tested it, but your __new__ looks fine. The only thing you
lose by not calling super() is the inability for cooperative multiple
inheritance, except as the ultimate base class.
--
~Ethan~
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