From: David Pollak <pollak@...>
Date: 2006-05-04T01:07:02+09:00
Subject: Re: Constant in Ruby.

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You're freezing the Object that is assigned to X.  If you want to freeze th=
e
class that owns X, you can try:
class Foo
  X =3D "Hello".freeze # nobody can change the string out from under us
end

Foo.freeze # now, you can't change the Foo class

That should do what you want.

On 4/29/06, Charlie <peckcharlie@yahoo.com> wrote:
>
> Mike Fletcher wrote:
> > Charlie wrote:
> >> I'm new to Ruby programming and I saw this article which concerns me:
> >>
> >> http://www.bitwisemag.com/copy/features/opinion/ruby/ruby_debate.html
> >>
> >> Don't get me wrong, I love Ruby. But, the idea that a constant is not =
a
> >> constant is worrying isn't it? Or have I missed something? Please
> >> comment.
> >>
> >> X =3D 10
> >> Y =3D "hello world"
> >> Z =3D "hello world"
> >>
> >> X =3D 20
> >> Y =3D "byebye" << "abc"
> >> myvar =3D Z << "xyz"
> >>
> >> puts(X)
> >> 20
> >> puts(Y)
> >> byebyeabc
> >> puts(Z)
> >> hello worldxyz
> >> myvar
> >> "hello worldxyz"
> >
> > It's constant in that you can't reassign a different instance to the
> > same name (try setting X =3D 10 after you've set it to 20 and Ruby will
> > gripe).  The instances themselves may still be mutable (see
> > Object#freeze if you want to change that).
>
> okay, I just try this:
>
> X =3D 20
> X =3D 10
> puts(X)
> 10
> X.freeze
> X =3D 30
> puts(X)
> 30
>
>    Sorry, but I find it difficult to understand as I'm new to it. Would
> be helpful if you can enlighten me with some examples. Thanks.
>
>
>
>
> --
> Posted via http://www.ruby-forum.com/.
>
>


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--------
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