[Python-Dev] C-level duck typing

[Robert Bradshaw]

On Wed, May 16, 2012 at 5:03 PM, Greg Ewing <greg.ewing at canterbury.ac.nz> wrote:
> Dag wrote:
>
>> I'm not asking you to consider the details of all that. Just to allow some
>> kind of high-performance extensibility of PyTypeObject, so that we can
>> *stop* bothering python-dev with specific requirements from our parallel
>> universe of nearly-all-Cython-and-Fortran-and-C++ codebases :-)
>
>
> Maybe you should ask for a bit more than that.
>
> Tp_flags bits are a scarce resource, and they shouldn't
> be handed out lightly to anyone who asks for one. Eventually
> they're going to run out, and then something else will have to
> be done to make further extensions of the type object possible.
>
> So maybe it's worth thinking about making a general mechanism
> available for third parties to extend the type object without
> them all needing to have their own tp_flags bits and without
> needing to collude with each other to avoid conflicts.

This is exactly what was proposed to start this thread (with minimal
collusion to avoid conflicts, specifically partitioning up a global ID
space).

- Robert