source: trunk/essentials/dev-lang/python/Demo/metaclasses/Meta.py@ 3226

"""Generic metaclass.

XXX This is very much a work in progress.

"""

import types

class MetaMethodWrapper:

    def __init__(self, func, inst):
        self.func = func
        self.inst = inst
        self.__name__ = self.func.__name__

    def __call__(self, *args, **kw):
        return apply(self.func, (self.inst,) + args, kw)

class MetaHelper:

    __methodwrapper__ = MetaMethodWrapper # For derived helpers to override

    def __helperinit__(self, formalclass):
        self.__formalclass__ = formalclass

    def __getattr__(self, name):
        # Invoked for any attr not in the instance's __dict__
        try:
            raw = self.__formalclass__.__getattr__(name)
        except AttributeError:
            try:
                ga = self.__formalclass__.__getattr__('__usergetattr__')
            except (KeyError, AttributeError):
                raise AttributeError, name
            return ga(self, name)
        if type(raw) != types.FunctionType:
            return raw
        return self.__methodwrapper__(raw, self)

class MetaClass:

    """A generic metaclass.