From: Robert Klemme <bob.news@...>
Date: 2003-05-21T17:56:34+09:00
Subject: Re: An Object Going Out Of Scope


"Mauricio Fern�ndez" <batsman.geo@yahoo.com> schrieb im Newsbeitrag
news:20030521055137.GA6046@student.ei.uni-stuttgart.de...
> On Wed, May 21, 2003 at 05:14:06AM +0900, MikkelFJ wrote:
> >
> > "Jim Weirich" <jweirich@one.net> wrote in message
> > news:1053406677.17559.8.camel@traken...
> >
> > > How about this syntax ...
> > >
> > >    auto(foo=MyObject.new, :cleanup) do
> > >      # use foo
> > >    end
> >
> > fine if you can handle multiple objects this way. Mauricios suggestion
does
> > that, but does not allow you to specify cleanup method. This, of
course can
> > be done in many ways.
>
> It seems you overlooked the fact that it is not implementable in current
> Ruby, for it needs Procs to be rebound :)

I'm not sure, whether I understand you correctly.  The solution below does
work.  Why then is it not possible without rebinding procs?

> It'd be easy to change it to specify the cleanup method, should it run
> at all.
>
> def auto(hash)
> ..
> end
>
> and then
>
> auto( :a => :finalize, :file => close ) do
>  file = File.new("/tmp/bla")
>  a  = Something.new
> end

How about:

def auto2( hash )
  begin
    yield
  ensure
    hash.each do |obj, method|
      obj.send method
    end
  end
end

class Foo
  def cleanup
    puts "cleanup"
  end
end

auto2( Foo.new => :cleanup ) do
  puts "in block"
end

    robert