Add a method as C extension to a class defined in Ruby


#1

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?

If not, how to fill MY_CLASS here?:

rb_define_method(MY_CLASS, “my_method”, my_method, arg_count);

Thanks.


#2

On Sat, 2009-04-04 at 00:45 +0900, Iñaki Baz C. 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


#3

2009/4/3 Andre N. removed_email_address@domain.invalid:

  return Qnil;

class Foo; end
require ‘foo’
Foo.new.foo

Thanks a lot!


#4

On Apr 3, 2009, at 09:03, Andre N. wrote:

return Qnil;
}

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

It’s better with RubyInline:

require ‘rubygems’
require ‘inline’

class Foo
inline :C do |builder|
builder.c <<-C
void foo() {
rb_p(INT2FIX(42));
}
C
end
end

Foo.new.foo