On Wed, Nov 22, 2017 at 4:47 PM, Gregory Ewing
<greg.ew...@canterbury.ac.nz> wrote:
> Cameron Simpson wrote:
>>
>> one could change implementations such that applying a docstring to an
>> object _removed_ it from the magic-shared-singleton pool,
>
>
> That's not sufficient, though. Consider:
>
> BUFFER_SIZE = 256
> BUFFER_SIZE.__doc__ = "Size of the buffer"
>
> TWO_TO_THE_EIGHT = 256
> TWO_TO_THE_EIGHT.__doc__ = "My favourite power of two"
>
> Before the code is even run, the compiler may have merged the
> two occurences of the integer literal 256 into one entry in
> co_consts. By the time the docstrings are assigned, it's too
> late to decide that they really needed to be different objects.
>
> So, an int with a docstring needs to be explicitly created as
> a separate object to begin with, one way or another.
class Int(int):
def __new__(cls, *a, **kw):
__doc__ = kw.pop("doc", None)
self = super().__new__(cls, *a, **kw)
self.__doc__ = __doc__
return self
BUFFER_SIZE = Int(256, doc="Size of the buffer")
ChrisA
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