From: Robert Klemme <bob.news@...>
Date: 2004-06-10T19:58:44+09:00
Subject: Re: question about private method


"wang" <wwayya2004@hotmail.com> schrieb im Newsbeitrag
news:dc1b9b9.0406100210.2305b0e@posting.google.com...
> wwayya2004@hotmail.com (wang) wrote in message
news:<dc1b9b9.0406081833.6228ed2e@posting.google.com>...
> > In ruby FAQ :
> > The visibility keyword private makes a method callable only in a
> > function form, and so it can only have self as a receiver.
> > But,why i can't write like below?
> >
> > class Test
> >   def func
> >     self.test   #use self
> >   end
> >
> >   private
> >   def test
> >     p "test"
> >   end
> > end
> >
> > t=Test.new
> > t.func   >>in `func': private method `test' called for
> > #<Test:0x2ac7318>NoMethodError)
>
> Thanks all!
> Maybe i wasn't express my thought clearly.
> I read "...it can only have self as a receiver..." in FAQ, so i call
> "test" with "self" but wrong. What the really mean of "self" in FAQ?

The receiver is implicitely 'self' if you invoke a method without
explicitely stating the receiver.  There's a simple rule: there are no
functions in Ruby, only methods.  So 'self' points to a valid instance under
all circumstances (even in methods belonging to nil, which is different than
Java's 'null' and C's (void*)0).

>> class Foo; def test; p self; test2; end; private; def test2; p self; end;
end
=> nil
>> o=Foo.new
=> #<Foo:0x10181448>
>> o.test
#<Foo:0x10181448>
#<Foo:0x10181448>
=> nil

Regards

    robert