[Pyrex] How could I embed/inline a small piece of c code in pyrex file?

Mon Mar 13 16:04:12 CET 2006

Hi, guys,

In pyrex source file, how could I wrap the c struct like that:

typedef struct _xEvent {
    union {
        struct {
            BYTE type;
            BYTE detail;
            CARD16 sequenceNumber B16;
            } u;
        struct {
            CARD32 pad00 B32;
            Time time B32;
            Window root B32, event B32, child B32;
            INT16 rootX B16, rootY B16, eventX B16, eventY B16;
            ... ...
        } keyButtonPointer;
    ... ...
   }u;
}xEvent;

I found I can not use nested ctypedef in pyrex. Currently, I am doing 
like this way:

cdef extern from "X11/Xproto.h":
    ctypedef struct s1:
        unsigned char type
        unsigned char detail

    ctypedef struct s2:
        unsigned short rootX
        unsigned short rooty

    ctypedef union s3:
        s1 u
        s2 keyButtonPointer

    ctypedef struct xEvent:
        s3 u

Do you have cleaner and better solutions?

Regards,

Yong Sun wrote:
> Hi, Helmut,
>
> Thank you very much!
> However, I only want to embed a c code snippet instead of a c 
> function, I don't know whether pyrex will support this feature in 
> future :)
>
> BTW, how did you deal with the #define constant in C source? I use 
> "ctypedef enum:" block to re-declare them.
>
> Regards,
>
> Helmut Jarausch wrote:
>> I don't know any way of including inline code.
>> What I have done is this
>>
>> Put your inline code into a C function  'Myfct'
>> and put the complete function definition into
>> a file  'MyCcode.h'
>>
>> Then put the following 2 lines into your Pyrex code
>>
>> cdef extern from "MyCcode.h"
>>   <here repeat just the declaration of Myfct>
>>
>> Then you can call 'Myfct' in any of your Pyrex functions
>>
>> Helmut.
>>
>>
>> On 13 Mar, Yong Sun wrote:
>>  
>>> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
>>> <html>
>>> <head>
>>>   <meta content="text/html;charset=UTF-8" http-equiv="Content-Type">
>>> </head>
>>> <body bgcolor="#ffffff" text="#000000">
>>> Hi, guys,<br>
>>> <br>
>>> I am writing a python module for X record extension. I have a callback
>>> need to access the data member of xEvent:<br>
>>> <blockquote>cdef void _event_callback_wrapper (XPointer priv,
>>> XRecordInterceptData *hook):<br>
>>>     cdef xEvent *data<br>
>>>     data = &lt;xEvent*&gt; hook.data<br>
>>>     if (hook.category != XRecordFromServer):<br>
>>>         XRecordFreeData (hook)<br>
>>>         return<br>
>>>     ... ...<br>
>>> </blockquote>
>>> In order to access the members of one xEvent structure, I need declare
>>> it as:<br>
>>> <blockquote>cdef extern from "X11/Xproto.h":<br>
>>>     ctypedef struct xEvent<br>
>>>         ... ...<br>
>>>         ... ...<br>
>>> </blockquote>
>>> Then I could use xEvent.member instead of xEvent-&gt;member to access
>>> the members.<br>
>>> <br>
>>> However, the xEvent definition is too long and too complex, I am
>>> wondering could I directly inline a small piece of c code to access
>>> this structure, if I can ensure the reference counting or other issues?
>>> <br>
>>> <br>
>>> Just like the following:<br>
>>> <blockquote>cdef void _event_callback_wrapper (XPointer priv,
>>> XRecordInterceptData *hook):<br>
>>>     cdef xEvent *data<br>
>>>     data = &lt;xEvent*&gt; hook.data<br>
>>>     if (hook.category != XRecordFromServer):<br>
>>>         XRecordFreeData (hook)<br>
>>>         return<br>
>>>     ''' inline c code:<br>
>>>     switch (data-&gt;type) {<br>
>>>     case KeyPress:<br>
>>>     case KeyRelease:<br>
>>>     ... ...<br>
>>>     }<br>
>>>     '''<br>
>>> </blockquote>
>>> Regards,<br>
>>> <br>
>>> </body>
>>> </html>
>>>
>>>     
>>
>>   
>
>
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