Raymond Hettinger <rhettin...@users.sourceforge.net> added the comment:
This would be an important fix-up if we could find some way to implement it.
The basic problem is that the class object is defined after the class
definitions have been made, so the target of the Graph reference isn't known
when the method definitions are being compiled.
One approach to solving this problem is to use a deferred/resolved pattern
(creating a valid reference to Graph that is visible during method compilation,
but gets filled-in with the other methods afterwards).
I haven't thought this through completely but think it could be done if we let
the compiler write to the class dictionary (this is normally off-limits and
protected by a dict_proxy). If we let the system punch a hole in the proxy, it
is possible to resolve deferred class definitions.
Here's a concept sketch:
class Prepared(type):
'Preload the class with a reference to itself'
@classmethod
def __prepare__(mcl, name, bases):
return {name: type(name, bases, {})}
def __new__(mcl, name, bases, mapping):
tmpcls = super().__new__(mcl, name, bases, mapping)
deferred_class = mapping[name]
deferred_class.__dict__.update(tmpcls.__dict__) # XXX need writeable
dict_proxy
return deferred_class
class Graph(metaclass=Prepared):
----------
_______________________________________
Python tracker <rep...@bugs.python.org>
<http://bugs.python.org/issue11339>
_______________________________________
_______________________________________________
Python-bugs-list mailing list
Unsubscribe:
http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
