From: Wayne Vucenic <nightphotos@...>
Date: 2005-12-09T07:55:23+09:00
Subject: Re: rescue anything raised?

Hi Daniel,

On 12/8/05, Daniel Schierbeck <daniel.schierbeck@gmail.com> wrote:
> Jeffrey Moss wrote:
> > rescue Exception
> >
> > All exceptions descend from class Exception.
> >
> > -Jeff
>
> I actually think that's kinda non-rubyish. Why not simply require
> objects to have the basic methods of an exception (`exception', and
> maybe `message', `backtrace', etc.) to qualify as an exception?
>
>   class FooException
>     attr_reader :message
>
>     def initialize(message)
>       @message = message
>     end
>
>     def exception(message = nil)
>       if message.nil?
>         return self
>       else
>         self.new(message)
>       end
>     end
>   end

You can raise any object whose exception method returns an Exception. 
So your example would become:

class FooException
  def initialize(message)
    @message = message
  end

  def exception
    Exception.new(@message)
  end
end

begin
  raise FooException.new("I'm a foo exception")
rescue Exception => e
  p e
end

which outputs

#<Exception: I'm a foo exception>

Wayne

---
Wayne Vucenic
No Bugs Software
"Ruby and C++ Agile Contract Programming in Silicon Valley"