From: Yukihiro Matsumoto <matz@...>
Date: 2009-11-05T23:14:11+09:00
Subject: Re: Freeze not freezing

Hi,

In message "Re: Freeze not freezing"
    on Thu, 5 Nov 2009 23:05:28 +0900, Ralph Shnelvar <ralphs@dos32.com> writes:

|a) Is my reasoning correct?

#freeze protect an object from modification.  The reference is not the
target of freezing.

|b) Is there a way to do what I want? That is, freeze f or c[0] so that
|I get some sort of message/error/exception?

You can protect an array (or object) as a whole, since it is an
object, so that

  c=[0,1]
  c.freeze
  c[0]=2    # => can't modify frozen array (RuntimeError)

but you cannot freeze any variables.

|c) Do my examples violate POLS?

No.  Unlike C++, variables and references are not object in any sense
in Ruby.  From my viewpoint, C++ violates POLS. ;-)

							matz.