def simplegeneric(func):
    """Make a trivial single-dispatch generic function"""
    registry = {}
    def wrapper(*args, **kw):
        ob = args[0]
        try:
            cls = ob.__class__
        except AttributeError:
            cls = type(ob)
        try:
            mro = cls.__mro__
        except AttributeError:
            try:
                class cls(cls, object):
                    pass
                mro = cls.__mro__[1:]
            except TypeError:
                mro = object,   # must be an ExtensionClass or some such  :(
        for t in mro:
            if t in registry:
                return registry[t](*args, **kw)
        else:
            return func(*args, **kw)
    try:
        wrapper.__name__ = func.__name__
    except (TypeError, AttributeError):
        pass    # Python 2.3 doesn't allow functions to be renamed

    def register(typ, func=None):
        if func is None:
            return lambda f: register(typ, f)
        registry[typ] = func
        return func

    wrapper.__dict__ = func.__dict__
    wrapper.__doc__ = func.__doc__
    wrapper.register = register
    return wrapper
Make a trivial single-dispatch generic function
debugger/src/_pydev_imps/_pydev_pkgutil_old.py