From: Andre Nathan <andre@...>
Date: 2009-04-04T01:03:11+09:00
Subject: Re: Add a method as C extension to a class defined in Ruby

On Sat, 2009-04-04 at 00:45 +0900, I単aki Baz Castillo wrote:
> Hi, in case I want to add a method (using C) for a class I've created
> in pure Ruby, must I also create the class in C?

Something like this should work:

static VALUE
rb_foo(VALUE self)
{
    rb_p(INT2FIX(42));
    return Qnil;
}

void
Init_foo(void)
{
    VALUE klass = rb_const_get(rb_cObject, rb_intern("Foo"));
    rb_define_method(klass, "foo", rb_foo, 0);
}

Then you should be able to do

class Foo; end
require 'foo'
Foo.new.foo

HTH,
Andre