From: Andre Nathan <andre@...>
Date: 2009-03-30T01:52:49+09:00
Subject: Re: Passing block in C

Hi Peter,

On Sun, 2009-03-29 at 23:30 +0900, Peter Zotov wrote:
> Hi.
> 
> How can I call Ruby function from C with block?

You can use rb_iterate():

static VALUE
foo_i(VALUE x, VALUE dummy)
{
    rb_p(x);
    return Qnil;
}

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

static VALUE
call_foo(VALUE klass)
{
    return rb_funcall(klass, rb_intern("foo"), 0);
}

void
Init_myclass(void)
{
    VALUE klass = rb_define_class("MyClass", rb_cObject);
    rb_define_singleton_method(klass, "foo", rb_foo, 0);
    rb_iterate(call_foo, klass, foo_i, (VALUE)NULL);
}

Best,
Andre