Nick Coghlan wrote:
> On Thu, May 10, 2012 at 6:11 PM, Mark Shannon <m...@hotpy.org> wrote:
>> Finally, could you remind me how the proposed type.define differs from
>> builtins.__build_class__?
>> I can't see any difference (apart from parameter ordering and the extra name
>> parameter in builtins.__build_class__).

> It's the officially supported version of that API - the current
> version is solely a CPython implementation detail. The main change is
> moving exec_body to the end and making it optional, thus bringing the
> interface more in line with calling a metaclass directly. The name
> parameter is actually still there, I just forgot to include in the
> examples in the thread.

> You'll find there's no mention of __build_class__ in the language or
> library references, thus there's currently no official way to
> programmatically define a new type in a way that complies with PEP
> 3115.

> (This is explained in the tracker issue and the previous thread that
> proposed the name operator.build_class)

> I prefer type.define(), but if the descriptor protocol does cause
> problems (and making static methods callable doesn't fix them), then
> we'll move it somewhere else (probably types.define() with a new
> _types module).