ÿØÿàJFIFÿþ ÿÛC       ÿÛC ÿÀÿÄÿÄ"#QrÿÄÿÄ&1!A"2qQaáÿÚ ?Øy,æ/3JæݹÈ߲؋5êXw²±ÉyˆR”¾I0ó2—PI¾IÌÚiMö¯–þrìN&"KgX:Šíµ•nTJnLK„…@!‰-ý ùúmë;ºgµŒ&ó±hw’¯Õ@”Ü— 9ñ-ë.²1<yà‚¹ïQÐU„ہ?.’¦èûbß±©Ö«Âw*VŒ) `$‰bØԟ’ëXÖ-ËTÜíGÚ3ð«g Ÿ§¯—Jx„–’U/ÂÅv_s(Hÿ@TñJÑãõçn­‚!ÈgfbÓc­:él[ðQe 9ÀPLbÃãCµm[5¿ç'ªjglå‡Ûí_§Úõl-;"PkÞÞÁQâ¼_Ñ^¢SŸx?"¸¦ùY騐ÒOÈ q’`~~ÚtËU¹CڒêV  I1Áß_ÿÙ"""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. This can be subclassed to implement various kinds of meta-behavior. """ __helper__ = MetaHelper # For derived metaclasses to override __inited = 0 def __init__(self, name, bases, dict): try: ga = dict['__getattr__'] except KeyError: pass else: dict['__usergetattr__'] = ga del dict['__getattr__'] self.__name__ = name self.__bases__ = bases self.__realdict__ = dict self.__inited = 1 def __getattr__(self, name): try: return self.__realdict__[name] except KeyError: for base in self.__bases__: try: return base.__getattr__(name) except AttributeError: pass raise AttributeError, name def __setattr__(self, name, value): if not self.__inited: self.__dict__[name] = value else: self.__realdict__[name] = value def __call__(self, *args, **kw): inst = self.__helper__() inst.__helperinit__(self) try: init = inst.__getattr__('__init__') except AttributeError: init = lambda: None apply(init, args, kw) return inst Meta = MetaClass('Meta', (), {}) def _test(): class C(Meta): def __init__(self, *args): print "__init__, args =", args def m1(self, x): print "m1(x=%r)" % (x,) print C x = C() print x x.m1(12) class D(C): def __getattr__(self, name): if name[:2] == '__': raise AttributeError, name return "getattr:%s" % name x = D() print x.foo print x._foo ## print x.__foo ## print x.__foo__ if __name__ == '__main__': _test()