From: Hidetoshi NAGAI <nagai@...>
Date: 2004-05-06T13:41:07+09:00
Subject: Re: $SAFE = 3.5?

Hi, 

From: Tim Bates <tim@bates.id.au>
Subject: Re: $SAFE = 3.5?
Date: Tue, 4 May 2004 07:58:42 +0900
Message-ID: <4096CE96.7000702@bates.id.au>
>    class Safe
>      def level(lvl)
>        th = Thread.new do
>          $SAFE = lvl.to_i
>          yield
>        end
>        th.join
>      end
>    end

A proc object can be used as a safe-level wrapper. 
Please try the following script. 
===============================================================
###################
# sample part 1
###################
class Safe
  def self.level(lvl)
    proc{$SAFE=lvl.to_i; yield}.call
  end
end

p $SAFE
p Safe.level(2){puts '----';p $SAFE; puts '-----'; $SAFE}
p $SAFE
puts '========================='

###################
# sample part 2
###################
fp = open('hoge', 'w')
wp = proc{|s| p $SAFE; fp.print(s)}

puts '========================='
$SAFE = 4
wp.call("hoge hoge\n")
fp.print("fuge fuge\n")
===============================================================
-- 
                                  Hidetoshi NAGAI (nagai@ai.kyutech.ac.jp)