From: Chris Hulan <chris.hulan@...>
Date: 2010-04-07T02:10:08+09:00
Subject: Re: Custom Exceptions

On Apr 6, 11:56 am, Brian Candler <b.cand...@pobox.com> wrote:
> Chris Hulan wrote:
> > The default Exception:initialize is defined to take 1 parameter, a
> > string containing the error message
>
> But 'raise' also lets you pass an error message, in addition to the
> exception instance.
>
> Note that even the default constructor doesn't create an instance
> variable called @message.
>
> class Foo < StandardError
> end
>
> begin
>   raise Foo, "bar"
> rescue Foo => e
>   p e
>   p e.instance_variables
>   p e.instance_variable_get(:@message)
>   p e.message
>   p e.backtrace
> end
>
> #<Foo: bar>
> []              # << No instance variables!
> nil             # << No @message!
> "bar"
> ["ert.rb:5"]
> --
> Posted viahttp://www.ruby-forum.com/.

I should stop answering questions based on reading the docs at ruby-
docs.org, they are just not very clear...plus sloppy reading on my
part doesn't help ;)
So message is not an attribute so using @message is wrong.
It looks like overriding to_s, or maybe using super in the override of
message to get the parents input.

cheers