[Python-Dev] Slot for __trunc__

[Guido van Rossum]

On Jan 29, 2008 11:34 AM, Raymond Hettinger <python at rcn.com> wrote:
> [GvR]
> > I don't see why. __index__ has a slot because its
> > primary use is to be called from C code, where slots
> > add a slight performance advantage.
> > __trunc__ doesn't get called from C AFAIK.
>
> I thought the __trunc__ method only gets called from
> the C code for the trunc() function which is currently
> implemented with PyObject_CallMethod(number, "__trunc__", "")
> instead of a fast call to a slot.

I see.

Well, it would bounce around a bit but it would never execute Python
byte codes. I don't see trunc() being all that performance critical.
The cost of adding a new slot is considerable -- for one, *all* type
objects become 4 (or 8) bytes longer.

-- 
--Guido van Rossum (home page: http://www.python.org/~guido/)