From: Shan-leung Maverick WOO <maverick@...>
Date: 2001-07-05T07:36:12+09:00
Subject: [ruby-talk:17254] extension and GC

Hello,

I am writing an extension X in C. It creates a new class which inherits from
Hash. So in Init_X(), instead of passing rb_cObject to rb_define_class, I
used rb_cHash. 

Here comes the two questions:

1. When the user creates the object, I want my own new routine to be called
first. I do this by defining a singleton method "new" mapping to my C
function X_new(). In my case, I believe I need to call super because Ruby
has to construct the hash. So I called:

    rb_enable_super(rb_cHash, "new");
    rb_call_super(argc, argv);

But the first line already generates an error:
> in `new': undefined method `new' for class `Hash' (NameError)

What's the correct way to call rb_enable_super?

2. In X_new(), I also allocated some memory. But since I am not wrapping a
structure, I don't know when to free the memory. Perhaps I am just plain
wrong extending Hash this way?

And if this helps: I am actually using Ruby as an extension language to my
app and so I want to create a "conf" object which is a Ruby hash with all
its existing methods and some of my own methods. That's why when I defined
the class I used rb_cHash as the parent (so that I get all the existing
methods).

Thanks!

-- 
All the best,
Maverick Woo