[MacRuby-devel] How to use custom C struct's?

[Laurent Sansonetti]

On Aug 5, 2009, at 8:41 AM, Eloy Duran wrote:

> Hi,
>
> On Aug 5, 2009, at 5:31 PM, Clay Bridges wrote:
>> The google didn't yield much guidance on this. Before I started a
>> deep-dive on the MacRuby source, and/or the standard ruby way to
>> handle this sort of thing, I thought I would ask a couple of
>> questions:
>>
>> 1) Any easy advice?
>
> Yes, use RubyCocoa
>
>> 2) Is this different in MacRuby than in ruby proper?
>
> RubyCocoa at least allows you to use BridgeSupport which would allow  
> you to map these. Afaik MacRuby doesn't fully support it yet.
>
>> 3) Any pointers into the MacRuby source that might help me?
>
> BridgeSupport needs to fully implemented.

FYI, BridgeSupport is mostly implemented in MacRuby, at least the part  
that deals with C structures. The only part that we didn't implement  
yet is C function pointers, the rest (roughly 90%) is done, and it is  
faster / more stable than the RubyCocoa code (you will have to believe  
me, since I wrote both :-)).

What Clay needs to do is describe his C structures in a .bridgesupport  
file.

You can read the BridgeSupport(5) man-page for more information.  
Unfortunately the gen_bridge_metadata(1) cannot generate C structures  
metadata without a template, and this part is not yet documented. So  
it may be faster to craft the .bridgesupport file by hand. There are  
plenty of .bridgesupport files in /System/Library/Frameworks that can  
be used as an example.

Once the file is created, it can loaded from MacRuby using:

   load_bridge_support_file 'foo.bridgesupport'

Laurent