From: Daniel Brockman <daniel@...>
Date: 2005-07-26T10:34:50+09:00
Subject: Re: An array updatable?

Hi EdUarDo,

> Why can I access cars and modify it if I have not declared
> it [with] attr_writer?

JEGII> The code you show is not changing cars, it's just
JEGII> calling methods on the Array cars holds.  If you want
JEGII> to disallow this, you'll need to do some forwarding,
JEGII> for the methods you wish to allow.  However, I say
JEGII> think and make sure this is strictly necessary before
JEGII> you bolt down the gates.

You might also ask yourself whether you really need to
expose the array object itself.  You may be able to get away
with defining #each and including Enumerable, for instance.

   class BunchaCars
     include Enumerable
   
     def initialize(name)
       @cars = Array.new
       @name = name
     end
   
     def each
       @cars.each { |x| yield x }
     end
   end

This approach may or may not be appropriate in your case.
(We'd need more information to be able to tell.)

-- 
Daniel Brockman <daniel@brockman.se>

    So really, we all have to ask ourselves:
    Am I waiting for RMS to do this?   --TTN.