[MacRuby-devel] Using the MacRuby framework to embed ruby in Objective-C

[Laurent Sansonetti]

Hi Luke,

On Nov 25, 2008, at 2:57 PM, Luke Evans wrote:

> Hi,
>
> Thanks for MacRuby, I'm going to follow its development closely.   
> While I wouldn't use Ruby (without static typing) for large-scale  
> development, IMHO, it is my favourite scripting language for those  
> "little jobs", and I'm currently interested in it as an embedded  
> language in my app.
>
> Given the interest, I thought I would try creating a mini obj-c  
> project, including the MacRuby framework, to attempt some simple  
> interactions with ruby from obj-c.  Accordingly, I created some toy  
> code:
>
> - (void)awakeFromNib {
> 	ruby_init();
> 	rb_eval_string("puts 'hello world'");
> 	ruby_finalize();
> }
>
> Running my little app, results in a series of messages of the form"
> warning: Could not find object file "/private/tmp/trunk/xxxxx.o" -  
> no debug information available for "xxxxx.c"
> where xxxxx are things like "array", "bignum", "class",  
> "compar", ... etc.
>
> The app then crashes with a stack walk back containing a huge number  
> of nested exceptions (it seems).
>
> Now, it's quite possible that I'm just not driving this right (to  
> date I've always scripted in Ruby, and never attempted to drive it  
> from C).  Equally, I'd imagine that it's possible that the 0.3  
> version of the framework isn't up to this yet.
> If I can get past this point, I can see the objective-c interfacing  
> functions in the header file, so things might be peachy from then  
> on :-)
>
> Can anyone enlighten me?

MacRuby trunk ships an Objective-C API that you can use to communicate  
with the interpreter.

See the include/ruby/objc.h file for the API:

http://www.macruby.org/trac/browser/MacRuby/trunk/include/ruby/objc.h

And the sample-macruby/EmbeddedMacRuby project for an example:

http://www.macruby.org/trac/browser/MacRuby/trunk/sample-macruby/EmbeddedMacRuby

Note that there are currently 2 known bugs about this "feature". These  
will be fixed for 0.4 (the next release).

http://www.macruby.org/trac/ticket/164
http://www.macruby.org/trac/ticket/165

Laurent