On Sun, May 13, 2012 at 8:35 PM, Dag Sverre Seljebotn <d.s.seljeb...@astro.uio.no> wrote: > On 05/12/2012 08:44 PM, Nathaniel Smith wrote: >> >> On Fri, May 11, 2012 at 2:25 PM, Dag Sverre Seljebotn >> <d.s.seljeb...@astro.uio.no> wrote: >>> >>> This comes from a refactor of the work on CEP 1000: A PEP proposal, with >>> a >>> hack for use in current Python versions and in the case of PEP rejection, >>> that allows 3rd party libraries to agree on extensions to PyTypeObject. >>> >>> http://wiki.cython.org/enhancements/cep1001 >>> >>> If this makes it as a PEP, I don't think we need to think about having >>> CEP >>> 1000 accepted as a PEP. >>> >>> Comments? >> >> >> There should probably be some discussion of memory management for the >> tpe_data pointers. (I assume it's "guaranteed to be valid for as long >> as the associated PyTypeObject, and the PyTypeObject is responsible >> for making sure any necessary cleanup happens if it gets deallocated", >> but a note to this effect would be good.) >> >> What happens if I want to inherit from PyTypeObject (a "metaclass") >> and also implement this interface? It is possible? What if I want to >> inherit from an existing subclass of PyTypeObject and add on this >> interface? I don't know enough gnarly details about how new style >> classes are implemented to tell. Would it make sense to make this >> memory-layout-equivalent to a PyTypeObject subclass with extra fields? > > > Hmm. You know what -- this whole thing could probably be a metaclass.
Well, yes, conceptually, that's exactly what it is -- the question is how and whether it relates to the Python metaclass machinery, since you are speed freaks :-). > Except > I think a PyObject_TypeCheck on the type would be a bit more expensive than > just checking a flag. I think I like having a flag better... A number of existing flags are actually used exactly to make type-checking faster for some key types (PY_TPFLAGS_INT_SUBCLASS, etc.). I guess doing it the same way would put the flag in obj->tp_class->tp_class->tp_flags, though, instead of obj->tp_class->tp_flags. - N _______________________________________________ cython-devel mailing list cython-devel@python.org http://mail.python.org/mailman/listinfo/cython-devel
