From: btricha@...
Date: 2008-05-07T11:01:26+09:00
Subject: Re: Yet another question about extending ruby with C

Hi Albert,

Thanks for responding. Sorry for not making things clear and easy to
follow... I was in a hurry when I wrote it. :/ I'll try and clear
things up when I have a chance. Thanks again!

--
Bryan

On 5/6/08, Albert Schlef <albertschlef@gmail.com> wrote:
> Bryan Richardson wrote:
> > Say I have the following:
> >
> > typedef struct {
> >   char* name;
> > } Foo;
> >
> > [...]
> >
> > static VALUE foo_init(VALUE self) {
> >   VALUE str;
> >   char* name = "Bryan";
> >   str = rb_str_new2(name);
> >   rb_iv_set(self, "@name", str);
> >   return self;
> > }
> >
> > static VALUE test(VALUE self, VALUE arg) {
> >   Foo* f;
> >   Data_Get_Struct(arg, Foo, f);
> >   printf("Name: %s\n", f->name);
> >   return Qnil;
> > }
> >
> > [...]
> >
> > If I do the following, everything works perfectly and I see my name
> > printed
> > on the screen:
> >
> > [...]
> > b.test(f)  // prints "Bryan"
>
> "works perfectly"? I don't see how it can print "Bryan", for two
> reasons:
>
> 1. It's supposed to print "Name: Bryan", not "Bryan".
>
> 2. But it can't print "Name: Bryan" either. That's because in foo_init()
> you aren't settings f->name to "Bryan". Instead, you're settings an
> instance variable, "@name", to "Bryan". It happens that "@name" has a
> similar name to char *name, but these two variables aren't related at
> all.
>
> Last but not least:
>
> If you want ppl to help you, you must make it easier for them to help
> you. Do that by choosing _sane_ names for your
> methods/structures/variables. I had a hard time following your code (and
> that in your previous question). 'test', 'Test' and 'Foo' aren't
> meaningful names. Change them to make_person, Person, and person_rec.
> --
> Posted via http://www.ruby-forum.com/.
>
>