[Python-3000] Metaclasses in Python 3000: Draft 2

[Steven Bethard]

On 3/14/07, Talin <talin at acm.org> wrote:
> PEP: xxx
> Title: Metaclasses in Python 3000

Looks good.

>      # The metaclass
>      class OrderedClass(type):
>
>          # The custom dictionary
>          class member_table(dict):
>             def __init__(self):
>                self.member_names = []
>
>             def __setitem__(self, key, value):
>                # if the key is not already defined, add to the
>                # list of keys.
>                if key not in self:
>                   self.member_names.append( key )
>
>                # Call superclass
>                dict.setitem(self, key value)

Should probably be ``dict.__setitem__(self, key, value)``.

>          # The prepare function
>          @classmethod
>          def __prepare__(cls, name, bases):  # No keywords in this case
>             return self.member_table()

Should probably be:

@classmethod
def __prepare__(meta, name, bases):
    return meta.member_table()


Perhaps __prepare__ should be special-cased like __new__ so that it's
always a @classmethod?

STeVe
-- 
I'm not *in*-sane. Indeed, I am so far *out* of sane that you appear a
tiny blip on the distant coast of sanity.
        --- Bucky Katt, Get Fuzzy