From: Brian Marick <marick@...>
Date: 2001-06-29T13:02:13+09:00
Subject: [ruby-talk:17042] rescuing qualified names

Does 'rescue' obey the scope operator ::?

Suppose I override the token "Exception" in a module:

module T
  class Exception < ::Exception
  end
end

Then, if I want a 'rescue' clause to catch all exceptions, I think I should
need to qualify it as "::Exception":

module T
  class Zow
    def raiser
      begin
        Zow.new.bogus
      rescue ::Exception
        puts 'rescued'   # parse error here
      end
    end
  end
end

However, this yields a parse error (in 1.6.3):

(irb):12: parse error
      rescue ::Exception
               ^

If I use an expression that returns the constant "::Exception", it parses:

module T
  class Zow
    def raiser
      ename = ::Exception
      begin
        Zow.new.bogus
      rescue ename
        puts "rescued #{$!.class}"
      end
    end
  end
end

Moreover, it does indeed catch all exceptions:

>  T::Zow.new.raiser
rescued NameError
nil

Is this a bug? I don't see it in the bug database or the 1.6.3->1.6.4 changes.

--
Brian Marick, marick@testing.com
www.testing.com - Software testing services and resources
www.testingcraft.com - Where software testers exchange techniques
www.visibleworkings.com - Adequate understanding of system internals