[Python-Dev] PEP 435 - ref impl disc 2

[Ethan Furman]

On 05/04/2013 11:31 PM, Glenn Linderman wrote:
>
> x = NamedInt('the-x', 1 )
> y = NamedInt('the-y', 2 )
> # demonstrate that NamedInt propagates the names into an expression syntax
> print( repr( x ), repr( y ), repr( x+y ))
>
> from ref435 import Enum
>
> # requires redundant names, but loses names in the expression
> class NEI( NamedInt, Enum ):
>      x = NamedInt('the-x', 1 )
>      y = NamedInt('the-y', 2 )
>
> print( repr( NEI( 1 )), repr( NEI( 2 )), repr( NEI(1) + NEI(2)))

Well, my first question would be why are you using named anything in an enumeration, where it's going to get another name?

But setting that aside, if you

--> print(NEI.x.__name__)
'x'

not 'the-x'.

Now let's look for the clues:

class Enum...
     ...
     @StealthProperty
     def name(self):
         return self._name

class NamedInt...
     ...
     def __name__(self):
         return self._name  # look familiar?


When NamedInt goes looking for _name, it finds the one on `x`, not the one on `x.value`.

--
~Ethan~