[Pyrex] A problem in generating Python extension types.

[Lenard Lindstrom]

Daehyok Shin wrote:
> I am trying to replace complex C structures with Python extension
> types generated from PyRex code. My purpose is to create Python
> extension types which allows other C programs to access structure
> variables inside the extension types.
>
> A problem I met during the development may be best explained with the
> following simple example.
>
> ---------  C Code --------------------------------
> struct child_object {
>   int ID;
> }
>
> struct parent_object {
>   struct child_object *child;
> }
>
> ----------   PyRex Code  ------------------------
> public Child[object child_object, type child_type]:
>   cdef public int ID
>
> public Parent[object parent_object, type parent_type]:
>   cdef Child child
>
>   def __new__(self)
>     self.child = Child() # I got an error message here when compiling
> generated C code.
>
>   def __dealloc_(self):
>     del self.child
>
>   
I can't comment on this code because it isn't value Pyrex.

"1:7: Syntax error in simple statement list"


> I succeeded in creating the same C structures from the above PyRex
> code, but when I compiled the generated C code, I got an error message
> because self.child expects a pointer to child_object  but Child()
> returns a pointer to PyObject.
> Is there any way I can solve this problem so that the extension types
> act as a commond data models for both Python programs and C programs.
> Thanks in advance.
>
>   
After converting everything into extension class declarations and 
removing the "del self.child" I got it to compile in Pyrex 0.9.4.1. My 
gcc 3.4.5 compiler only generated a warning when compiling the resulting 
C code. So this is likely a Pyrex bug since early versions expected a 
forgiving C compiler.


-- 
Lenard Lindstrom
<len-l at telus.net>