[Cython] [PATCH] Make __Pyx_ArgTypeTest() use "const char*" to suppress warning

[Dag Sverre Seljebotn]

Lisandro Dalcin wrote:
> On Wed, Sep 10, 2008 at 12:53 PM, Stefan Behnel <stefan_ml at behnel.de> wrote:
>> Lisandro Dalcin wrote:
>>> On Wed, Sep 10, 2008 at 11:35 AM, Stefan Behnel <stefan_ml at behnel.de>
>>> wrote:
>>>> This specific case is easy to handle as we can replace
>>>> PyObject_GetAttrString() by the equivalent PyObject_GetAttr() call and
>>>> create the Python string ourselves (which would normally happen inside
>>>> of PyObject_GetAttrString).
>>> As a reminder, please use PyString_InternFromString() (or the py3k
>>> equivalent).
>> I considered doing that and rejected it as I do not see the gain in
>> re-re-building the Python string instead of creating it once. Why do you
>> think this is necessary?
> 
> Well, this is the way that PyObject_GetAttrString() is implemented. If
> the call ends-up doing many dicts lookups (think about the chain
> instance->class->[intermediate_class]->base_class), then using a
> interned string is much faster (as string comparison ends-up being a
> pointer comparison). In short, I believe this is a good optimization
> if Cython wants its own version of PyObject_GetAttrString()
> implemented in terms of PyObject_GetAttr().

I think Stefan is referring to a different approach: The string will be 
created at module startup time and held on to. So your point is valid 
but there's an even better approach :-) (assuming here that the module 
startup interns the string, which seems very very likely but I didn't 
check it).

-- 
Dag Sverre