Possible incoherences on Py_TPFLAGS_HEAPTYPE.

[Boris Boutillier]

I don't know if this is the right place to ask my question, but if needed
I'll post it on the python-dev mailing list.

I'm writing a C-extension module for python 2.3.
I need to declare a new class, MyClass.
For this class I want two things :
1) redefine the setattr function on objects of this class
(ie setting a new tp_setattro)
2) I want that the python user can change attributes on MyClass (the
class itself).

Now I have a conflict on the Py_TPFLAGS_HEAPTYPE with new Python 2.3.
If I have Py_TPFLAGS_HEAPTYPE set on MyClass, I'll have problem with the
new hackcheck (Object/typeobject.c:3631), as I am a HEAPTYPE but I also
redefine tp_setattro.
If I don't have Py_TPFLAGS_HEAPTYPE, the user can't set new attributes on
my class because of a check in type_setattro (Object/typeobject.c:2047).

Have I missed something ?

Boris

 

[Michael Hudson]

I don't know if this is the right place to ask my question, but if needed
I'll post it on the python-dev mailing list.

I'm writing a C-extension module for python 2.3.
I need to declare a new class, MyClass.
For this class I want two things :
1) redefine the setattr function on objects of this class
(ie setting a new tp_setattro)
2) I want that the python user can change attributes on MyClass (the
class itself).

Now I have a conflict on the Py_TPFLAGS_HEAPTYPE with new Python 2.3.
If I have Py_TPFLAGS_HEAPTYPE set on MyClass, I'll have problem with the
new hackcheck (Object/typeobject.c:3631), as I am a HEAPTYPE but I also
redefine tp_setattro.
If I don't have Py_TPFLAGS_HEAPTYPE, the user can't set new attributes on
my class because of a check in type_setattro (Object/typeobject.c:2047).

Have I missed something ?

Not sure. You might want to consider a custom metaclass, but I
understand they're painful in C (and I'm not even sure that would
solve the problem).

Cheers,
mwh

--

> Touche! But this confirms you are composed of logic gates.

Crud, I thought those were neurons in there.
-- Thomas F. Burdick, Kenny Tilton, comp.lang.lisp

 

[Boris Boutillier]

Do you think this question should be sent to Python-Dev ?
I am subscribed to the Python-Dev mailing list but never posted on it.

Boris