Re: [Python-Dev] Slot for __trunc__
On Jan 29, 2008 11:34 AM, Raymond Hettinger [EMAIL PROTECTED] 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/) ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Slot for __trunc__
Raymond Hettinger 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. And if __trunc__ qualifies, what about __format__, which is similar? I'm not pushing for it, I just wonder how the decision is made. Eric. ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Slot for __trunc__
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.
On Jan 29, 2008 11:04 AM, Raymond Hettinger [EMAIL PROTECTED] wrote:
Should the implementation of __trunc__ have its own slot like we have for
nb_index?
Raymond
---
[EMAIL PROTECTED] ~/py26/Objects $ grep __trunc__ *.c
floatobject.c: {__trunc__, (PyCFunction)float_trunc, METH_NOARGS,
intobject.c:{__trunc__, (PyCFunction)int_int, METH_NOARGS,
longobject.c: {__trunc__, (PyCFunction)long_long, METH_NOARGS,
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--
--Guido van Rossum (home page: http://www.python.org/~guido/)
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[Python-Dev] Slot for __trunc__
Should the implementation of __trunc__ have its own slot like we have for
nb_index?
Raymond
---
[EMAIL PROTECTED] ~/py26/Objects $ grep __trunc__ *.c
floatobject.c: {__trunc__, (PyCFunction)float_trunc, METH_NOARGS,
intobject.c:{__trunc__, (PyCFunction)int_int, METH_NOARGS,
longobject.c: {__trunc__, (PyCFunction)long_long, METH_NOARGS,
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Re: [Python-Dev] Slot for __trunc__
[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. Raymond ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
