From: matz@... (Yukihiro Matsumoto)
Date: 2001-11-07T15:15:37+09:00
Subject: [ruby-talk:24486] Re: C Extension Help

Hi,

In message "[ruby-talk:24465] C Extension Help"
    on 01/11/07, Jason Voegele <jason@jvoegele.com> writes:

|I'm trying to write some additional collection classes for Ruby, such
|as Sets, Trees, Bags, Linked Lists, etc.  I've got a working Ruby
|version for some of them, but I'm currently attempting to implement a
|Set (backed by a Ruby Hash) as a C extension, but I'm not much of a C
|programmer and I got a run-time error I can't figure out.

rb_iterate calls block_proc with arguments (element, arg), so that
set_add is called as set_add(element, 0).

So I modified your source to:

  #include "ruby.h"

  static VALUE init_i(VALUE item, VALUE self)
  {
      VALUE hash = rb_iv_get(self, "@store");

      rb_funcall(hash, rb_intern("store"), 2, item, item);
      return item;
  }

  static VALUE set_initialize(int argc, VALUE *argv, VALUE self)
  {
      VALUE elements;
      VALUE store = rb_hash_new();

      rb_iv_set(self, "@store", store);
      rb_scan_args(argc, argv, "01", &elements);
      if (RTEST(elements)) {
          rb_iterate(rb_each, elements, init_i, self);
      }
      return self;
  }

  Init_set()
  {
      VALUE set = rb_define_class( "Set", rb_cObject);
      rb_define_method(set, "initialize", set_initialize, -1);
  }

And it seems to work.

							matz.