From: "Brian Schröder" <ruby.brian@...>
Date: 2005-06-03T02:22:01+09:00
Subject: Re: Implementing a Read-Only array

On 02/06/05, Robert Klemme <bob.news@gmx.net> wrote:
> Gavin Kistner wrote:
> > On Jun 1, 2005, at 4:11 PM, Brian Schr�der wrote:
> >>> Gavin Kistner wrote:
> >>>>>> affectors = %w| << []= clear concat delete delete_at delete_if
> >>>>>> fill flatten! insert map! pack pop push reject! replace reverse!
> >>>>>> shift slice! sort! uniq! unshift |
> >>
> >> Though this means that you have to override all methods that can
> >> change the array. I'd shurely forget something in this case. You
> >> forgot e.g. #clear. Therefore I'd propose to explicitly delegate the
> >> needed methods for the application because this is easier to control.
> >
> > But again, that way prevents users' convenience methods for Arrays/
> > Enumerables from being available.
> 
> Yeah, I prefer the method to explicitely exclude mutators, too.  The
> reason being that IMHO there are more often non modifying convenience
> methods defined on Array than modifying methods.
> 

Just playing devils advocate here, but if you care about user added
methods, the user may also add something that acts in effekt like

class Array
  def mutate(i, v)
    self[i] = v
  end
end

which you certainly would like to remove. Though I have to disclaim
that I personally would simply stick with a simple array and a note
not to change its contents ;-) If it breaks, you will know it and if
it does not it's also good.

best regards,

Brian


-- 
http://ruby.brian-schroeder.de/

Stringed instrument chords: http://chordlist.brian-schroeder.de/